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Copyright © 2008, New Age International (P) Ltd., Publishers Published by New Age International (P) Ltd., Publishers

All rights reserved. No part of this ebook may be reproduced in any form, by photostat, microfilm, xerography, or any other means, or incorporated into any information retrieval system, electronic or mechanical, without the written permission of the publisher. All inquiries should be emailed to [email protected]

ISBN (13) : 978-81-224-2627-4

PUBLISHING FOR ONE WORLD NEW AGE INTERNATIONAL (P) LIMITED, PUBLISHERS 4835/24, Ansari Road, Daryaganj, New Delhi - 110002 Visit us at www.newagepublishers.com Dedicated to

PROF. DR. F.V. MANVI SecretarySecretarySecretary KLE Society, BELGAUM KARNATAKA.

“To My First Pharmacy teacher with Love” This page intentionally left blank FOREWORD

Competitive Examinations are the order of the day. All Colleges conducting professional courses at PG level are admitting students based on common entrance examination, which is of objective type. In Pharmacy, M.Pharm admissions are based on qualifying the GATE enterance examination conducted by Govt. of India. In this book, The author has done good work in preparing several objective questions which help the students to face the subject in the examination with poise and confidence. The book is well balanced and consists of multiple choice questions from all the important topics like carbohydrate and other important Biochemical aspects. The typesetting and quality of printing is good. The author is also well experienced in taking up this type of work. I recommend this book to all the students preparing for GATE examination and also for Medical and Pharmacy College libraries.

PROF. B.G. SHIVANANDA Principal

AL-AMEEN COLLEGE OF PHARMACY BANGALORE. WATER AND ELECTROLYTE BALANCE 289

PREFPREFPREFAAACECECE

I have brought out this book basically for students who plan to appear for in the entrance examinations like JIPMER and other Medical, Pharmacy, Physiotherapy, Nursing and other Paramedical PG Entrance Examinations. There is a dearth of good entrance manual of Biochemistry for the above said examinations. Hence, I have prepared an exhaustive Question bank of around 5000 MCQs with answers covering a wide spectrum of basic Biochemical topics of the subject. Some of the important topics which are given a good coverage include Carbohydrate metabolism, metabo- lism, Lipid metabolism, Nucleic acids, , Vitamins and Mineral metabolism. The objective questions are prepared based on the background taken from previous question papers of Profes- sional medical and Paramedical competitive entrance examinations. The book serves as a ready reckoner for Biochemistry as far as objective pattern is concerned. I feel satisfied if the book serves the purpose for which it is intended. I have tried to minimize typographical errors but still some must have crept in. If they are brought to my notice, I will be rectifying them in the next edition. Constructive Criticism is always welcome G. Vidya Sagar AAACKNOWLEDGEMENTS

I wish to express my profound gratitude and benevolence to the following who were the inspiring force in making this book a reality • Prof. Dr. Kishor Pramod Bhusari • Sadhvi Shilapiji Principal, Nagpur College of Pharmacy Chair person, Veerayatan Vidyapeeth, Nagpur. Jakhaniya, Kutch, Gujarat • Prof. Dr. R. Rangari • Prof. Dr. R.K. Goyal Principal, J.N. Chaturvedi College of Pharmacy L.M. College of Pharmacy Nagpur Ahmedabad, Gujarat • Prof. Dr. Anant Naik Nagappa • Prof. Dr. A.K. Saluja Pharmacy group, Birla Institute of Technology & A.R. College of Pharmacy Sciences Vallabh Vidyanagar Pilani, Rajasthan Gujarat • Prof. Dr. Srinivas Rao • Prof. J.V.L.N. Sheshagiri Rao Principal, VEL’s College of Pharmacy Dept. of Pharmaceutical Sciences Chennai Andhra University, Vishakhapatnam, A.P. Finally, I express my gratitude to Mr. Saumya Gupta. MD, New Age International (P) Limited, New Delhi, for his encouragement and support. Dr. G.Vidya Sagar SOME VVSOME ALUALUALUABLE COMMENTS

This book is very useful for students appearing for GATE Exams. Recommended reading. Prof. Dr. Subhas C. Marihal Principal, Goa College of Pharmacy, Goa.

Biochemistry made simple in the form of multiple choice questions. Strongly recommended. Prof. Dr. Vijaykumar Ishwar Hukkeri Principal, KLE College of Pharmacy, Hubli

Dr. Vidya Sagar can be applauded for his untiring efforts in bringing out such a good book. Recommended for students and Library Dr. G. Devala Rao Principal, Sidhartha College of Pharmaceutical Sciences Vijaywada, A.P.

This book will be very useful companion for students appearing for PG Medical, Pharmacy, Nursing and Physiotherapy competitive exams. Prof. Dr. T.K. Ravi Principal, Sri Ramakrishna Institute of Pharmaceutical Science Coimbatore.

MCQs are well framed, mostly from previous entrance examinations. Commendable work. Prof. Madhukar R. Tajne Deptt. of Pharmaceutical Sciences, Nagpur University, Nagpur CCCONTENTSONTENTSONTENTS

Preface (x) Chapter 1 INTRODUCTION TO BIOCHEMISTRY 111 CHAPTER 2 CARBOHYDRATES AND CARBOHYDRATE METMETTE ABOLISMABOLISMABOLISM 555 CHAPTER 3 PROPROPROTEINS & PROTEIN METMETTEIN ABOLISMABOLISMABOLISM 272727 CHAPTER 4 FFFAAATS & FFTS AAATTY AATTY CID METMETCID ABOLISMABOLISMABOLISM 757575 CHAPTER 5 VITVITVITAMINSAMINSAMINS 113113113 CHAPTER 6 ENZYMESENZYMESENZYMES 141141141 CHAPTER 7 MINERAL METABOLISMABOLISMABOLISM 183183183 CHAPTER 8 HORMONE METABOLISMABOLISMABOLISM 209209209 CHAPTER 9 NUCLEIC ACIDSCIDSCIDS 237237237 CHAPTER 10 WWWAAATER & ELECTROLYTE BALANCE 281281281 This page intentionally left blank CHAPTER 111

I INTRODUCTION TOTOTO BBBIOCHEMISTRY

1. A drug which prevents uric acid synthesis 8. Which are the cholesterol esters that enter by inhibiting the xanthine cells through the receptor-mediated is endocytosis of lipoproteins hydrolyzed? (A) Aspirin (B) Allopurinol (A) Endoplasmin reticulum (C) Colchicine (D) Probenecid (B) Lysosomes (C) Plasma membrane receptor 2. Which of the following is required for crystallization and storage of the (D) Mitochondria hormone insulin? 9. Which of the following phospholipids is (A) Mn++ (B) Mg++ localized to a greater extent in the outer leaflet of the membrane lipid bilayer? (C) Ca++ (D) Zn++ (A) Choline phosphoglycerides 3. Oxidation of which substance in the body (B) Ethanolamine phosphoglycerides yields the most calories (C) Inositol phosphoglycerides (A) Glucose (B) Glycogen (D) phosphoglycerides (C) Protein (D) Lipids 10. All the following processes occur rapidly 4. Milk is deficient in which vitamins? in the membrane lipid bilayer except (A) Vitamin C (B) Vitamin A (A) Flexing of fatty acyl chains

(C) Vitamin B2 (D) Vitamin K (B) Lateral diffusion of phospholipids 5. Milk is deficient of which mineral? (C) Transbilayer diffusion of phopholipids (D) Rotation of phospholipids around their long (A) Phosphorus (B) Sodium axes (C) Iron (D) Potassium 11. Which of the following statement is 6. Synthesis of prostaglandinsis is inhibited correct about membrane cholesterol? by (A) The hydroxyl group is located near the centre (A) Aspirin (B) Arsenic of the lipid layer (C) Fluoride (D) Cyanide (B) Most of the cholesterol is in the form of a 7. HDL is synthesized and secreted from cholesterol ester (C) The steroid nucleus form forms a rigid, planar (A) Pancreas (B) Liver structure (C) Kidney (D) Muscle 2 MCQs IN BIOCHEMISTRY

(D) The hydrocarbon chain of cholesterol projects (C) Dihydrolipoyl into the extracellular fluid (C) All of these 12. Which one is the heaviest particulate 21. The most of protein synthesis component of the cell? is the (A) Nucleus (B) Mitochondria (A) Nucleus (B) Ribosome (C) Cytoplasm (D) Golgi apparatus (C) Mitochondrion (D) Cell sap 13. Which one is the largest particulate of the 22. The fatty acids can be transported into cytoplasm? and out of mitochondria through (A) Lysosomes (A) Active transport (B) Mitochondria (B) Facilitated transfer (C) Golgi apparatus (C) Non-facilitated transfer (D) Entoplasmic reticulum (D) None of these 14. The degradative Processess are categorized 23. Mitochondrial DNA is under the heading of (A) Circular double stranded (A) Anabolism (B) Catabolism (B) Circular single stranded (C) Metabolism (D) None of the above (C) Linear double helix 15. The exchange of material takes place (D) None of these (A) Only by diffusion 24. The absorption of intact protein from the (B) Only by active transport gut in the foetal and newborn animals (C) Only by pinocytosis takes place by (D) All of these (A) Pinocytosis (B) Passive diffusion (C) Simple diffusion (D) Active transport 16. The average pH of Urine is (A) 7.0 (B) 6.0 25. The cellular organelles called “suicide bags” are (C) 8.0 (D) 0.0 (A) Lysosomes (B) Ribosomes 17. The pH of blood is 7.4 when the ratio (C) Nucleolus (D) Golgi’s bodies between H2CO3 and NaHCO3 is (A) 1 : 10 (B) 1 : 20 26. From the biological viewpoint, solutions can be grouped into (C) 1 : 25 (C) 1 : 30 (A) Isotonic solution 18. The phenomenon of osmosis is opposite (B) Hypotonic solutions to that of (C) Hypertonic solution (A) Diffusion (B) Effusion (D) All of these (C) Affusion (D) Coagulation 27. Bulk transport across cell membrane is 19. The surface tension in intestinal lumen accomplished by between fat droplets and aqueous (A) Phagocytosis (B) Pinocytosis medium is decreased by (C) Extrusion (D) All of these (A) Bile Salts (B) Bile acids 28. The ability of the cell membrane to act as (C) Conc. H2SO4 (D) Acetic acid a selective barrier depends upon 20. Which of the following is located in the (A) The lipid composition of the membrane mitochondria? (B) The pores which allows small molecules (A) Cytochrome oxidase (C) The special mediated transport systems (B) (D) All of these INTRODUCTION TO BIOCHEMISTRY 3

29. Carrier protein can 35. Enzymes catalyzing electron transport (A) Transport only one substance are present mainly in the (B) Transport more than one substance (A) Ribosomes (C) Exchange one substance to another (B) Endoplasmic reticulum (D) Perform all of these functions (C) Lysosomes (D) Inner mitochondrial membrane 30. A lipid bilayer is permeable to (A) Urea (B) Fructose 36. Mature erythrocytes do not contain (C) Glucose (D) Potassium (A) Glycolytic enzymes(B) HMP shunt enzymes (C) Pyridine nucleotide(D) ATP 31. The Golgi complex (A) Synthesizes 37. In mammalian cells rRNA is produced mainly in the (B) Produces ATP (C) Provides a pathway for transporting chemicals (A) Endoplasmic reticulum (D) Forms glycoproteins (B) Ribosome (C) Nucleolus 32. The following points about microfilaments (D) Nucleus are true except (A) They form cytoskeleton with microtubules 38. Genetic information of nuclear DNA is transmitted to the site of protein synthesis (B) They provide support and shape by (C) They form intracellular conducting channels (A) rRNA (B) mRNA (D) They are involved in muscle cell contraction (C) tRNA (D) Polysomes 33. The following substances are cell inclusions except 39. The power house of the cell is (A) Melanin (B) Glycogen (A) Nucleus (B) Cell membrane (C) Lipids (D) Centrosome (C) Mitochondria (D) Lysosomes 34. Fatty acids can be transported into and 40. The digestive enzymes of cellular out of cell membrane by compounds are confined to (A) Active transport (B) Facilitated transport (A) Lysosomes (B) Ribosomes (C) Diffusion (D) Osmosis (C) Peroxisomes (D) Polysomes

ANSWERS 1. B 2. D 3. D 4. A 5. C 6. A 7. B 8. B 9. A 10. C 11. C 12. A 13. B 14. B 15. D 16. B 17. B 18. A 19. A 20. D 21. B 22. B 23. A 24. A 25. A 26. D 27. D 28. D 29. D 30. A 31. D 32. C 33. D 34. B 35. D 36. C 37. C 38. D 39. C 40. A This page intentionally left blank CHAPTER 2

CCCARBOHYDRATESTESTES ANDANDAND CCCARBOHYDRATETETE MMMETETETABOLISMABOLISMABOLISM

1. The general formula of monosaccharides 9. Two sugars which differ from one another is only in configuration around a single carbon atom are termed (A) CnH2nOn (B) C2nH2On

(C) CnH2O2n (D) CnH2nO2n (A) Epimers (B) Anomers 2. The general formula of polysaccharides (C) Optical isomers (D) Stereoisomers is 10. Isomers differing as a result of variations (A) (C6H10O5)n (B) (C6H12O5)n in configuration of the —OH and —H on

(C) (C6H10O6)n (D) (C6H10O6)n carbon atoms 2, 3 and 4 of glucose are known as 3. The aldose sugar is (A) Glycerose (B) Ribulose (A) Epimers (B) Anomers (C) Erythrulose (D) Dihydoxyacetone (C) Optical isomers (D) Steroisomers 4. A triose sugar is 11. The most important epimer of glucose is (A) Glycerose (B) Ribose (A) Galactose (B) Fructose (C) Erythrose (D) Fructose (C) Arabinose (D) Xylose 5. A pentose sugar is 12. ααα-D-glucose and β -D-glucose are (A) Dihydroxyacetone (B) Ribulose (C) Erythrose (D) Glucose (A) Stereoisomers (B) Epimers (C) Anomers (D) Keto-aldo pairs 6. The pentose sugar present mainly in the heart muscle is 13. ααα-D-glucose + 1120 → + 52.50 ← + 190 βββ- (A) Lyxose (B) Ribose D-glucose for glucose above represents (C) Arabinose (D) Xylose (A) Optical isomerism (B) Mutarotation 7. Polysaccharides are (C) Epimerisation (D) D and L isomerism (A) Polymers (B) Acids 14. Compounds having the same structural (C) Proteins (D) Oils formula but differing in spatial configuration are known as 8. The number of isomers of glucose is (A) Stereoisomers (B) Anomers (A) 2 (B) 4 (C) 8 (D) 16 (C) Optical isomers (D) Epimers 6 MCQs IN BIOCHEMISTRY

15. In glucose the orientation of the —H and (C) Glucose + galactose —OH groups around the carbon atom 5 (D) Glucose + mannose adjacent to the terminal primary alcohol carbon determines 25. The monosaccharide units are linked by 1 →→→ 4 glycosidic linkage in (A) D or L series (A) Maltose (B) Sucrose (B) Dextro or levorotatory (C) Cellulose (D) Cellobiose (C) α and β anomers (D) Epimers 26. Which of the following is a non-reducing sugar? 16. The carbohydrate of the blood group substances is (A) Isomaltose (B) Maltose (C) Lactose (D) Trehalose (A) Sucrose (B) Fucose (C) Arabinose (D) Maltose 27. Which of the following is a reducing sugar? 17. Erythromycin contains (A) Sucrose (B) Trehalose (A) Dimethyl amino sugar (C) Isomaltose (D) Agar (B) Trimethyl amino sugar (C) Sterol and sugar (D) Glycerol and sugar 28. A dissaccharide formed by 1,1-glycosidic linkage between their monosaccharide 18. A sugar alcohol is units is (A) Mannitol (B) Trehalose (A) Lactose (B) Maltose (C) Xylulose (D) Arabinose (C) Trehalose (D) Sucrose 19. The major sugar of insect hemolymph is 29. A dissaccharide formed by 1,1-glycosidic (A) Glycogen (B) Pectin linkage between their monosaccharide (C) Trehalose (D) Sucrose units is (A) Lactose (B) Maltose 20. The sugar found in DNA is (C) Trehalose (D) Sucrose (A) Xylose (B) Ribose (C) Deoxyribose (D) Ribulose 30. Mutarotation refers to change in (A) pH (B) Optical rotation 21. The sugar found in RNA is (C) Conductance (D) Chemical properties (A) Ribose (B) Deoxyribose (C) Ribulose (D) Erythrose 31. A polysacchharide which is often called animal starch is 22. The sugar found in milk is (A) Glycogen (B) Starch (A) Galactose (B) Glucose (C) Inulin (D) Dextrin (C) Fructose (D) Lactose 32. The homopolysaccharide used for 23. Invert sugar is intravenous infusion as plasma substitute (A) Lactose (B) Sucrose is (C) Hydrolytic products of sucrose (A) Agar (B) Inulin (D) Fructose (C) Pectin (D) Starch 24. Sucrose consists of 33. The polysaccharide used in assessing the glomerular fittration rate (GFR) is (A) Glucose + glucose (B) Glucose + fructose (A) Glycogen (B) Agar (C) Inulin (D) Hyaluronic acid CARBOHYDRATES AND CARBOHYDRATE METABOLISM 7

34. The constituent unit of inulin is 43. A polymer of glucose synthesized by the (A) Glucose (B) Fructose action of leuconostoc mesenteroids in a sucrose medium is (C) Mannose (D) Galactose (A) Dextrans (B) Dextrin 35. The polysaccharide found in the (C) Limit dextrin (D) Inulin exoskeleton of invertebrates is 44. Glucose on reduction with sodium (A) Pectin (B) Chitin amalgam forms (C) Cellulose (D) Chondroitin sulphate (A) Dulcitol (B) Sorbitol 36. Which of the following is a heteroglycan? (C) Mannitol (D) Mannitol and sorbitol (A) Dextrins (B) Agar 45. Glucose on oxidation does not give (C) Inulin (D) Chitin (A) Glycoside (B) Glucosaccharic acid 37. The glycosaminoglycan which does not (C) Gluconic acid (D) Glucuronic acid contain uronic acid is 46. Oxidation of galactose with conc HNO3 (A) Dermatan sulphate yields (B) Chondroitin sulphate (A) Mucic acid (B) Glucuronic acid (C) Keratan sulphate (C) Saccharic acid (D) Gluconic acid (D) Heparan sulphate 47. A positive Benedict’s test is not given by 38. The glycosaminoglycan which does not (A) Sucrose (B) Lactose contain uronic acid is (C) Maltose (D) Glucose (A) Hyaluronic acid 48. Starch is a (B) Heparin (C) Chondroitin sulphate (A) Polysaccharide (B) Monosaccharide (C) Disaccharide (D) None of these (D) Dermatan sulphate 49. A positive Seliwanoff’s test is obtained 39. Keratan sulphate is found in abundance with in (A) Glucose (B) Fructose (A) Heart muscle (B) Liver (C) Lactose (D) Maltose (C) Adrenal cortex (D) Cornea 50. Osazones are not formed with the 40. Repeating units of hyaluronic acid are (A) Glucose (B) Fructose (A) N-acetyl glucosamine and D-glucuronic acid (C) Sucrose (D) Lactose (B) N-acetyl galactosamine and D-glucuronic acid 51. The most abundant carbohydrate found (C) N-acetyl glucosamine and galactose in nature is (D) N-acetyl galactosamine and L- iduronic acid (A) Starch (B) Glycogen (C) Cellulose (D) Chitin 41. The approximate number of branches in amylopectin is 52. Impaired renal function is indicated when the amount of PSP excreted in the first 15 (A) 10 (B) 20 minutes is (C) 40 (D) 80 (A) 20% (B) 35% 42. In amylopectin the intervals of glucose (C) 40% (D) 45% units of each branch is 53. An early feature of renal disease is (A) 10–20 (B) 24–30 (C) 30–40 (D) 40–50 (A) Impairment of the capacity of the tubule to perform osmotic work 8 MCQs IN BIOCHEMISTRY

(B) Decrease in maximal tubular excretory 62. Fructose is present in hydrolysate of capacity (A) Sucrose (B) Inulin (C) Decrease in filtration factor (C) Both of the above (D) None of these (D) Decrease in renal plasma flow 63. A carbohydrate found in DNA is 54. ADH test is based on the measurement of (A) Ribose (B) Deoxyribose (A) Specific gravity of urine (C) Ribulose (D) All of these (B) Concentration of urea in urine 64. Ribulose is a these (C) Concentration of urea in blood (A) Ketotetrose (B) Aldotetrose (D) Volume of urine in ml/minute (C) Ketopentose (D) Aldopentose 55. The specific gravity of urine normally 65. A carbohydrate, commonly known as ranges from dextrose is (A) 0.900–0.999 (B) 1.003–1.030 (A) Dextrin (B) D-Fructose (C) 1.000–1.001 (D) 1.101–1.120 (C) D-Glucose (D) Glycogen 56. Specific gravity of urine increases in 66. A carbohydrate found only in milk is (A) Diabetes mellitus (A) Glucose (B) Galactose (B) Chronic glomerulonephritis (C) Lactose (D) Maltose (C) Compulsive polydypsia 67. A carbohydrate, known commonly as (D) Hypercalcemia invert sugar, is 57. Fixation of specific gravity of urine to (A) Fructose (B) Sucrose 1.010 is found in (C) Glucose (D) Lactose (A) Diabetes insipidus 68. A heteropolysacchraide among the (B) Compulsive polydypsia following is (C) Cystinosis (A) Inulin (B) Cellulose (D) Chronic glomerulonephritis (C) Heparin (D) Dextrin 58. Addis test is the measure of 69. The predominant form of glucose in solution is (A) Impairment of the capacity of the tubule to perform osmotic work (A) Acyclic form (B) Secretory function of liver (B) Hydrated acyclic form (C) Excretory function of liver (C) Glucofuranose (D) Activity of parenchymal cells of liver (D) Glucopyranose 70. An L-isomer of monosaccharide formed in 59. Number of stereoisomers of glucose is human body is (A) 4 (B) 8 (A) L-fructose (B) L-Erythrose (C) 16 (D) None of these (C) L-Xylose (D) L-Xylulose 60. Maltose can be formed by hydrolysis of 71. Hyaluronic acid is found in (A) Starch (B) Dextrin (A) Joints (B) Brain (C) Glycogen (D) All of these (C) Abdomen (D) Mouth 61. α –D–Glucuronic acid is present in 72. The carbon atom which becomes (A) Hyaluronic acid (B) Chondroitin sulphate asymmetric when the straight chain form of monosaccharide changes into ring (C) Heparin (D) All of these form is known as CARBOHYDRATES AND CARBOHYDRATE METABOLISM 9

(A) Anomeric carbon atom 82. Lactate formed in muscles can be utilised (B) Epimeric carbon atom through (C) Isomeric carbon atom (A) Rapoport-Luebeling cycle (D) None of these (B) Glucose- cycle 73. The smallest monosaccharide having (C) Cori’s cycle furanose ring structure is (D) cycle (A) Erythrose (B) Ribose 83. Glucose-6- is not present in (C) Glucose (D) Fructose (A) Liver and kidneys 74. Which of the following is an epimeric pair? (B) Kidneys and muscles (A) Glucose and fructose (C) Kidneys and adipose tissue (B) Glucose and galactose (D) Muscles and adipose tissue (C) Galactose and mannose 84. is regulated by (D) Lactose and maltose (A) Induction (B) Repression 75. ααα-Glycosidic bond is present in (C) (D) All of these (A) Lactose (B) Maltose 85. Fructose-2, 6-biphosphate is formed by (C) Sucrose (D) All of these the action of 76. Branching occurs in glycogen approxi- (A) -1 mately after every (B) Phosphofructokinase-2 (A) Five glucose units (C) Fructose biphosphate (B) Ten glucose units (D) Fructose-1, 6-biphosphatase (C) Fifteen glucose units 86. The highest concentrations of fructose are (D) Twenty glucose units found in 77. N–Acetylglucosamnine is present in (A) Aqueous humor (B) Vitreous humor (C) Synovial fluid (D) Seminal fluid (A) Hyaluronic acid (B) Chondroitin sulphate (C) Heparin (D) All of these 87. Glucose uptake by liver cells is 78. Iodine gives a red colour with (A) Energy-consuming (B) A saturable process (C) Insulin-dependent (D) Insulin-independent (A) Starch (B) Dextrin (C) Glycogen (D) Inulin 88. Renal threshold for glucose is decreased in 79. Amylose is a constituent of (A) Diabetes mellitus (B) Insulinoma (A) Starch (B) Cellulose (C) Renal glycosuria (D) Alimentary glycosuria (C) Glycogen (D) None of these 89. Active uptake of glucose is inhibited by 80. Synovial fluid contains (A) Ouabain (B) Phlorrizin (A) Heparin (C) Digoxin (D) Alloxan (B) Hyaluronic acid (C) Chondroitin sulphate 90. Glucose-6-phosphatase is absent or (D) sulphate deficient in (A) Von Gierke’s disease 81. Gluconeogenesis is decreased by (B) Pompe’s disease (A) Glucagon (B) Epinephrine (C) Cori’s disease (C) Glucocorticoids (D) Insulin (D) McArdle’s disease 10 MCQs IN BIOCHEMISTRY

91. Debranching enzyme is absent in 100. An amphibolic pathway among the (A) Cori’s disease following is (B) Andersen’s disease (A) HMP shunt (B) (C) Von Gierke’s disease (C) Citirc acid cycle (D) Gluconeogenesis (D) Her’s disease 101. Cori’s cycle transfers 92. McArdle’s disease is due to the deficiency (A) Glucose from muscles to liver of (B) Lactate from muscles to liver (A) Glucose-6-phosphatase (C) Lactate from liver to muscles (B) Phosphofructokinase (D) Pyruvate from liver to muscles (C) Liver 102. Excessive intake of ethanol increases the (D) muscle phosphorylase ratio: 93. Tautomerisation is (A) NADH : NAD+ (B) NAD+ : NADH

(A) Shift of hydrogen (B) Shift of carbon (C) FADH2 : FAD (D) FAD : FADH2 (C) Shift of both (D) None of these 103. Ethanol decreases gluconeogenesis by 94. In essential pentosuria, urine contains (A) Inhibiting glucose-6-phosphatase (A) D-Ribose (B) D-Xylulose (B) Inhibiting PEP carboxykinase (C) L-Xylulose (D) D-Xylose (C) Converting NAD+ into NADH and decreasing the availability of pyruvate 95. Action of salivary on starch leads (D) Converting NAD+ into NADH and decreasing to the formation of the availability of lactate (A) Maltose (B) Maltotriose 104. is (C) Both of the above (D) Neither of these (A) Uncoupler of oxidative phosphorylation 96. Congenital galactosaemia can lead to (B) Polymer of glycogen molecules (A) Mental retardation (C) Protein primer for glycogen synthesis (B) Premature cataract (D) Intermediate in glycogen breakdown (C) Death 105. During starvation, ketone bodies are used (D) All of the above as a fuel by 97. Uridine diphosphate glucose (UDPG) is (A) Erythrocytes (B) Brain (A) Required for metabolism of galactose (C) Liver (D) All of these (B) Required for synthesis of glucuronic acid 106. Animal fat is in general (C) A for glycogen synthetase (A) Poor in saturated and rich in polyunsaturated (D) All of the above fatty acids 98. Catalytic activity of salivary amylase (B) Rich in saturated and poor in polyunsaturated requires the presence of fatty acids (A) Chloride ions (B) Bromide ions (C) Rich in saturated and polyunsaturated fatty (C) Iodide ions (D) All of these acids (D) Poor in saturated and polyunsaturated fatty 99. The following is actively absorbed in the acids intestine: (A) Fructose (B) Mannose 107. In the diet of a diabetic patient, the recommended carbohydrate intake (C) Galactose (D) None of these should preferably be in the form of CARBOHYDRATES AND CARBOHYDRATE METABOLISM 11

(A) Monosaccharides (B) Dissaccharides 116. Heavy proteinuria occurs in (C) Polysaccharides (D) All of these (A) Acute glomerulonephritis 108. Obesity increases the risk of (B) Acute pyelonephritis (C) Nephrosclerosis (A) Hypertension (D) Nephrotic syndrome (B) Diabetes mellitus 117. Mucopolysaccharides are (C) Cardiovascular disease (D) All of these (A) Hamopolysaccharides (B) Hetropolysaccharides 109. Worldwide, the most common vitamin (C) Proteins deficiency is that of (D) Amino acids (A) Ascorbic acid (B) Folic acid 118. Bence-Jones protein precipitates at (C) Vitamin A (D) Vitamin D (A) 20°–40° C (B) 40–-60° C 110. Consumption of iodised salt is recom- (C) 60°–80° C (D) 80°–100° C mended for prevention of 119. Serum cholesterol is decreased in (A) Hypertension (B) Hyperthyroidism (A) Endemic goitre (B) Thyrotoxicosis (C) Endemic goitre (D) None of these (C) Myxoedema (D) Cretinism 111. Restriction of salt intake is generally 120. The heptose ketose sugar formed as a recommended in result of in HMP shunt: (A) Diabetes mellitus (B) Hypertension (A) Sedoheptulose (B) Galactoheptose (C) Cirrhosis of liver (D) Peptic ulcer (C) Glucoheptose (D) Mannoheptose 112. Polyuria can occur in 121. The general formula for polysaccharide is

(A) Diabetes mellitus (A) (C6H12O6)n (B) (C6H10O5)n

(B) Diarrhoea (C) (C6H12O5)n (D) (C6H19O6)n (C) Acute glomerulonephritis 122. The number of isomers of glucose is (D) High fever (A) 4 (B) 8 113. Normal specific gravity of urine is (C) 12 (D) 16 (A) 1.000–1.010 (B) 1.012–1.024 123. The epimers of glucose is (C) 1.025–1.034 (D) 1.035–1.045 (A) Fructose (B) Galactose 114. Specific gravity of urine is raised in all of (C) Ribose (D) Deoxyribose the following except 124. The intermediate in hexose monophos- (A) Diabetes mellitus phate shunt is (B) Diabetes insipidus (A) D-Ribolose (B) D-Arobinose (C) Dehydration (C) D-xylose (D) D-lyxose (D) Acute glomerulonephritis 125. Honey contains the hydrolytic of 115. Specific gravity of urine is decreased in (A) Lactose (B) Maltose (C) Inulin (D) Starch (A) Diabetes mellitus (B) Acute glomerulonephritis 126. On boiling Benedict’s solution is not (C) Diarrhoea reduced by (D) Chronic glomerulonephritis (A) Sucrose (B) Lactose (C) Maltose (D) Fructose 12 MCQs IN BIOCHEMISTRY

127. Glycosides are found in many 138. The component of cartilage and cornea is (A) Vitamins (B) Drugs (A) Keratosulphate (C) Minerals (D) Nucleoproteins (B) Chondroitin sulphate (C) Cadmium sulphate 128. Galactose on oxidation with conc. HNO 3 (D) Antimony sulphate produces (A) Gluconic acid (B) Saccharic acid 139. Benedict’s test is less likely to give weakly positive results with concentrated urine (C) Saccharo Lactone (D) Mucic acid due to the action of 129. The distinguishing test between mono- (A) Urea (B) Uric acid saccharides and dissaccharides is (C) Ammonium salts (D) Phosphates (A) Bial’s test (B) Selwanoff’s test 140. Active transport of sugar is depressed by (C) Barfoed’s test (D) Hydrolysis test the agent: 130. Cellulose is made up of the molecules of (A) Oxaloacetate (B) Fumarate (A) α-glucose (B) β-glucose (C) Malonate (D) Succinate (C) Both of the above (D) None of these 141. The general test for detection of 131. Iodine solution produces no color with carbohydrates is (A) Iodine test (B) Molisch test (A) Cellulose (B) Starch (C) Barfoed test (D) Osazone test (C) Dextrin (D) Glycogen 142. Glucose absorption may be decreased in 132. Glycogen structure includes a branch in between–glucose units: (A) Oedema (B) Nephritis (C) Rickets (D) Osteomalitis (A) 6–12 (B) 8–14 (C) 6–10 (D) 12–18 143. Glycogen synthetase activity is depressed by 133. Amylose contains glucose units (A) Glucose (B) Insulin (A) 100–200 (B) 200–300 (C) Cyclic AMP (D) (C) 300–400 (D) 500–600 144. The branching enzyme acts on the 134. Each branch of amylopectin is at an glycogen when the glycogen chain has interval of glucose units: been lengthened to between glucose units: (A) 14–20 (B) 24–30 (A) 1 and 6 (B) 2 and 7 (C) 34–40 (D) 44–50 (C) 3 and 9 (D) 6 and 11 135. N-acetylneuraminic acid is an example of 145. Cyclic AMP is formed from ATP by the (A) Sialic acid (B) Mucic acid enzyme adenylate cyclase which is activated by the hormone: (C) Glucuronic acid (D) Hippuric acid (A) Insulin (B) Epinephrine 136. In place of glucuronic acid chondroitin (C) Testosterone (D) Progesterone sulphate B contains (A) Gluconic acid (B) Gulonic acid 146. has a high affinity for glucose than (C) Induronic acid (D) Sulphonic acid (A) Fructokinase (B) 137. Blood group substances consist of (C) (D) All of the above (A) Lactose (B) Maltose (C) Fructose (D) Mucose 147. Dihydroxyacetone phosphate and glyceraldehyde-3-phosphate are intercoverted by CARBOHYDRATES AND CARBOHYDRATE METABOLISM 13

(A) Triose isomerase 156. Which of the following metabolite inte- (B) Phosphotriose isomerase grates glucose and fatty acid metabolism? (C) Diphosphotriose isomerase (A) Acetyl CoA (B) Pyruvate (D) Dihydroxyacetone phosphorylase (C) Citrate (D) Lactate 148. Citrate is converted to isocitrate by 157. Cerebrosides consist of mostly of this which contains sugar: (A) Ca++ (B) Fe++ (A) Glucose (B) Fructose (C) Zn++ (D) Mg++ (C) Galactose (D) Arabinose 149. The reaction succinyl COA to succinate 158. Glucose will be converted into fatty acids requires if the diet has excess of (A) CDP (B) ADP (A) Carbohydrates (B) Proteins (C) GDP (D) NADP+ (C) Fat (D) Vitamins 150. The carrier of the citric acid cycle is 159. The purple ring of Molisch reaction is due (A) Succinate (B) Fumarate to (C) Malate (D) Oxaloacetate (A) Furfural 151. UDPG is oxidized to UDP glucuronic acid (B) Furfural + α Napthol by UDP dehydrogenase in presence of (C) °C Napthol (A) FAD+ (B) NAD+ (D) Furfurol + H2SO4 + α -Naphthol (C) NADP+ (D) ADP+ 160. One of the following enzymes does not change glycogen a to b. 152. Galactose is phosphorylated by galacto- to form (A) 3, 4, 5 2+ (A) Galactose-6-phosphate (B) Ca calmodulin 2+ (B) Galactose-1, 6 diphosphate (C) Ca calmodulin dependent (C) Galactose-1-phosphate (D) a (D) All of these 161. In EM pathway -2-phosphoglycerate is 153. The conversion of alanine to glucose is converted to termed (A) Phospho enol pyruvate (A) Glycolysis (B) Enol pyruvate (B) Oxidative decarboxylation (C) Di hydroxy acetone phosphate (DHAP) (C) Specific dynamic action (D) 1,3 bisphosphoglycerate (D) Gluconeogenesis 162. An aneplerotic reaction which sustains the 154. The blood sugar raising action of the availability of oxaloacetate is the carbo- xylation of hormones of suprarenal cortex is due to (A) Glutamate (B) Pyruvate (A) Gluconeogenesis (C) Citrate (D) Succinate (B) Glycogenolysis (C) Glucagon-like activity 163. Specific test for ketohexoses: (D) Due to inhibition of glomerular filtration (A) Seliwanoff’s test (B) Osazone test (C) Molisch test (D) None of these 155. Under anaerobic conditions the glycolysis one mole of glucose yields __ moles of ATP. 164. Two important byproducts of HMP shunt are (A) One (B) Two (C) Eight (D) Thirty (A) NADH and pentose sugars (B) NADPH and pentose sugars 14 MCQs IN BIOCHEMISTRY

(C) Pentose sugars and 4 membered sugars 172. Conversion of glucose to glucose-6- (D) Pentose sugars and sedoheptulose phosphate in human liver is by (A) Hexokinase only 165. complex and ααα-ketoglutarate dehydrogenase complex (B) Glucokinase only require the following for their oxidative (C) Hexokinase and glucokinase decarboxylation: (D) Glucose-6-phosphate dehydrogenase (A) COASH and Lipoic acid 173. The following is an enzyme required for (B) NAD+ and FAD glycolysis: (C) COASH and TPP (A) + (D) COASH, TPP,NAD ,FAD, Lipoate (B) Pyruvate carboxylase 166. The four membered aldose sugar (C) Glucose-6-phosphatose phosphate formed in HMP shunt pathway (D) Glycerokinase is 174. The normal glucose tolerance curve (A) Xylulose P (B) Erythrulose P reaches peak is (C) Erythrose P (D) Ribulose P (A) 15 min (B) 1 hr 167. Cane sugar (Sucrose) injected into blood (C) 2 hrs (D) 2 ½ hrs is 175. Oxidative decarboxylation of pyruvate (A) changed to fructose requires (B) changed to glucose (A) NADP+ (C) undergoes no significant change (B) Cytichromes (D) changed to glucose and fructose (C) pyridoxal phosphate 168. Pentose production is increased in (D) COASH (A) HMP shunt 176. Glucose tolerance is increased in (B) Uromic acid pathway (A) Diabetes mellitus (B) Adrenalectomy (C) EM pathway (C) Acromegaly (D) Thyrotoxicosis (D) TCA cycle 177. Glucose tolerance is decreased in 169. Conversion of Alanine to carbohydrate is (A) Diabetes mellitus (B) Hypopituitarisme termed: (C) Addison’s disease (D) Hypothyroidism (A) Glycogenesis (B) Gluconeogenesis (C) Glycogenolysis (D) Photosynthesis 178. During glycolysis, Fructose 1, 6 diphos- phate is decomposed by the enzyme: 170. The following is an enzyme required for glycolysis: (A) Enolase a (B) Fructokinase (A) Pyruvate kinase (C) Aldolase (B) Pyruvate carboxylase (C) Glucose-6-phosphatase (D) Diphosphofructophosphatose (D) Glycerokinase 179. The following enzyme is required for the hexose monophosphate shunt pathway: 171. Our body can get pentoses from (A) Glycolytic pathway (A) Glucose-6-phosphatase (B) Uromic acid pathway (B) Phosphorylase (C) TCA cycle (C) Aldolase (D) HMP shunt (D) Glucose-6-phosphate dehydrogenase CARBOHYDRATES AND CARBOHYDRATE METABOLISM 15

180 Dehydrogenase enzymes of the hexose 189. The oxidation of lactic acid to monophosphate shunt are requires the following vitamin derivative (A) NAD+ specific (B) NADP+ specific as the hydrogen carrier. (C) FAD specific (D) FMN specific (A) Lithium pyrophosphate (B) Coenyzme A 181. Under anaerobic conditions the glycolysis + of one mole of glucose yields ______moles (C) NAD of ATP. (D) FMN (A) One (B) Two 190. Physiological glycosuria is met with in (C) Eight (D) Thirty (A) Renal glycosuria 182. Glycogen is converted to glucose-1- (B) Alimentary glycosuria phosphate by (C) Diabetes Mellitus (A) UDPG (B) Branching enzyme (D) Alloxan diabetes (C) Phosphorylase (D) Phosphatase 191. Two examples of substrate level phospho- rylation in EM pathway of glucose metab- 183. Which of the following is not an enzyme olism are in the reactions of involved in glycolysis? (A) 1,3 bisphosphoglycerate and phosphoenol (A) Euolase (B) Aldolose pyruvate (C) Hexokinase (D) (B) Glucose-6 phosphate and Fructo-6-phosphate 184. Tricarboxylic acid cycle to be continuous (C) 3 phosphoglyceraldehyde and phospho- requires the regeneration of enolpyruvate (A) Pyruvic acid (B) (D) 1,3 diphosphoglycerate and 2-phosphogly- (C) α-oxoglutaric acid (D) Malic acid cerate 185. Dehydrogenation of succinic acid to 192. The number of molecules of ATP produced requires the following by the total oxidation of acetyl CoA in hydrogen carrier: TCA cycle is + (A) NAD+ (B) NADP (A) 6 (B) 8 (C) flavoprotein (D) (C) 10 (D) 12

186. The tissues with the highest total glycogen 193. Substrate level phosphorylation in TCA content are cycle is in step: (A) Muscle and kidneys (A) (B) Kidneys and liver (B) (C) Liver and muscle (C) Aconitase (D) Brain and Liver (D) Succinate thiokinase

187. Rothera test is not given by 194. Fatty acids cannot be converted into carbohydrates in the body as the (A) β-hydroxy butyrate (B) bile salts following reaction is not possible. (C) Glucose (D) None of these (A) Conversion of glucose-6-phosphate into glucose 188. Gluconeogenesis is increased in the (B) Fructose 1,6-bisphosphate to fructose-6- following condition: phosphate (A) Diabetes insipidus (B) Diabetes Mellitus (C) Transformation of acetyl CoA to pyruvate (C) Hypothyroidism (D) Liver diseases (D) Formation of acetyl CoA from fatty acids 16 MCQs IN BIOCHEMISTRY

195. Tissues form lactic acid from glucose. This 202. Amylo 1, 6 glucosidase is called phenomenon is termed as (A) Branching enzyme (A) Aerobic glycolysis (B) debranching enzyme (B) Oxidation (C) Glucantransferase (C) Oxidative phosphorylation (D) Phosphorylase (D) Anaerobic glycolysis 203. Glucose enters the cells by 196. One molecule of glucose gives ______(A) insulin independent transport molecules of CO2 in EM-TCA cycle. (A) 6 (B) 3 (B) insulin dependent transport (C) 1 (D) 2 (C) enzyme mediated transport (D) Both (A) and (B) 197. One molecule of glucose gives ______

molecules of CO2 in one round of HMP 204. Glycogen while being acted upon by ac- shunt. tive phosphorylase is converted first to (A) 6 (B) 1 (A) Glucose (C) 2 (D) 3 (B) Glucose 1-phosphate and Glycogen with 1 198. The 4 rate limiting enzymes of carbon less gluconeogenesis are (C) Glucose-6-phosphate and Glycogen with 1 carbon less (A) Glucokinase, Pyruvate carboxylae phosphoenol pyruvate carboxykinase and (D) 6-Phosphogluconic acid glucose-6-phosphatase 205. When O2 supply is inadequate, pyruvate (B) Pyruvate carboxylase, phosphoenol pyruvate is converted to carboxykinase, fructose1,6 diphosphatase and glucose-6-phosphatase (A) Phosphopyruvate (B) Acetyl CoA (C) Pyruvate kinase, pyruvate carboxylase, (C) Lactate (D) Alanine phosphoenol pyruvate carboxykinase and 206. Reactivation of inactive liver phosphory- glucose-6-phosphatase lase is normally favoured by (D) Phospho fructokinase, pyruvate carboxylase, phosphoenol pyruvate carboxykinase and (A) Insulin (B) Epinephrine fructose 1, 6 diphosphatase (C) ACTH (D) Glucagon 199. For glycogenesis, Glucose should be con- 207. Before pyruvic acid enters the TCA cycle it verted to must be converted to (A) Glucuronic acid (B) Pyruvic acid (A) Acetyl CoA (B) Lactate (C) UDP glucose (D) Sorbitol (C) α-ketoglutarate (D) Citrate 200. Fluoride inhibits ______and arrests gly- 208. The hydrolysis of Glucose-6-phosphate is colysis. catalysed by a specific phosphatase (A) Glyceraldehyde-3-phosphate dehydrogenase which is found only in (B) Aconitase (A) Liver, intestines and kidneys (C) Enolose (B) Brain, spleen and adrenals (D) Succinate dehydrogenase (C) Striated muscle 201. One of the following statement is correct: (D) Plasma (A) Glycogen synthase ‘a’ is the phosphorylated 209. The formation of citrate from oxalo (B) cAMP converts glycogen synthase b to ‘a’ acetate and acetyl CoA is (C) Insulin converts glycogen synthase b to a (A) Oxidation (B) Reduction (D) UDP glucose molecules interact and grow into (C) Condensation (D) Hydrolysis a Glycogen tree CARBOHYDRATES AND CARBOHYDRATE METABOLISM 17

210. Which one of the following is a rate 218. Acetyl CoA is not used for the synthesis limiting enzyme of gluconeogenesis? of (A) Hexokinase (A) Fatty acid (B) Cholesterol (B) Phsophofructokinase (C) Pyruvic acid (D) Citric acid (C) Pyruvate carboxylase 219. The total glycogen content of the body is (D) Pyruvate kinase about ______gms. 211. The number of ATP produced in the (A) 100 (B) 200 succinate dehydrogenase step is (C) 300 (D) 500 (A) 1 (B) 2 220. The total Glucose in the body is ______(C) 3 (D) 4 gms. 212. Which of the following reaction gives (A) 10–15 (B) 20–30 lactose? (C) 40–50 (D) 60–80 (A) UDP galactose and glucose 221. Pyruvate kinase requires ______ions for (B) UDP glucose and galactose maximum activity. (C) Glucose and Galactose (A) Na+ (B) K+ (D) Glucose, Galactose and UTP (C) Ca2+ (D) Mg2+ 213. UDP Glucuronic acid is required for the 222. ATP is ‘wasted’ in Rapoport-Lueberring biosynthesis of cycle in RBCs as otherwise it will inhibit (A) Chondroitin sulphates (A) (B) Glycogen (B) Phosphohexo isomerase (C) Lactose (C) Phosphofructo kinase (D) Starch (D) Phosphoenol pyruvate carboxy kinase 214. Which one of the following can covert 223. The following co-enzyme is needed for the glucose to vitamin C? oxidative decarboxylation of ketoacids: (A) Albino rats (B) Humans (A) NADP+ (B) TPP (C) Monkeys (D) Guinea pigs (C) coenzyme (D) Biotin coenzyme 215. Which one of the following cannot convert 224. Synthesis of Glucose from amino acids is glucose to Vitamin C? termed as (A) Albino rats (B) Dogs (A) Glycolysis (B) Gluconeogenesis (C) Monkeys (D) Cows (C) Glycogenesis (D) Lipogenesis 216. has the coenzyme: 225. The following examples are important (A) NAD+ (B) FP heteropolysaccharides except (C) TPP (D) Pyridoxol phosphate (A) Amylopectin (B) Heparin (C) Peptidoglycan (D) Hyaluronic acid 217. Two conditions in which gluconeogenesis is increased are 226. Whcih of the following features are common to monosaccharides? (A) Diabetes mellitus and atherosclerosis (B) Fed condition and thyrotoxicosis (A) Contain asymmetric centres (C) Diabetes mellitus and Starvation (B) Are of 2 types – aldoses and ketoses (C) Tend to exist as ring structures in solution (D) Alcohol intake and cigarette smoking (D) Include glucose, galactose and raffinose 18 MCQs IN BIOCHEMISTRY

227. Polysaccharides 234. Which of the following compound is a (A) Contain many monosaccharide units which positive allosteric modifier of the enzyme may or may not be of the same kind pyruvate carboxylase? (B) Function mainly a storage or structural (A) Biotin (B) Acetyl CoA compounds (C) Oxaloacetate (D) ATP (C) Are present in large amounts in connective 235. A specific inhibitor for succinate tissue dehydrogenase is (D) All of these (A) Arsinite (B) Melouate 228. The absorption of glucose in the digestive (C) Citrate (D) Cyanide tract (A) Occurs in the small intestine 236. Most of the metabolic pathways are either anabolic or catabolic. Which of the (B) Is stimulated by the hormone Glucagon following pathways is considered as (C) Occurs more rapidly than the absorption of “amphibolic” in nature? any other sugar (A) Glycogenesis (B) Glycolytic pathway (D) Is impaired in cases of diabetes mellitus (C) Lipolysis (D) TCA cycle 229. UDP-Glucose is converted to UDP- Glucuronic acid by 237. Transketolase activity is affected in (A) ATP (B) GTP (A) Biotin deficiency (C) NADP+ (D) NAD+ (B) Pyridoxine deficiency (C) PABA deficiency 230. The enzymes involved in Phosphorylation of glucose to glucose 6- phosphate are (D) Thiamine deficiency (A) Hexokinase 238. The following metabolic abnormalities (B) Glucokinase occur in Diabetes mellitus except (C) Phosphofructokinase (A) Increased plasma FFA (D) Both (A) and (B) (B) Increased pyruvate carboxylase activate 231. In conversion of Lactic acid to Glucose, (C) Decreased lipogenesis three reactions of Glycolytic pathway are (D) Decreased gluconeogenesis circumvented, which of the following 239. A substance that is not an intermediate enzymes do not participate? in the formation of D-glucuronic acid from (A) Pyruvate Carboxylase glucose is (B) Phosphoenol pyruvate carboxy kinase (A) Glucoss-1-p (C) Pyruvate kinase (B) 6-Phosphogluconate (D) Glucose-6-phosphatase (C) Glucose-6-p 232. The normal resting state of humans, most (D) UDP-Glucose of the blood glucose burnt as “fuel” is consumed by 240. The hydrolysis of Glucose-6-P is catalysed by a phosphatase that is not formed in (A) Liver (B) Brain which of the following? (C) Kidneys (D) Adipose tissue (A) Liver (B) Kidney 233. A regulator of the enzyme Glycogen (C) Muscle (D) Small intestine synthase is 241. An essential for converting Glucose to (A) Citric acid Glycogen in Liver is (B) 2, 3 bisphosphoglycerate (A) Lactic acid (B) GTP (C) Pyruvate (C) CTP (D)UTP (D) GTP CARBOHYDRATES AND CARBOHYDRATE METABOLISM 19

242. Which of the following is a substrate for 249. Which of the following statements aldolase activity in Glycolytic pathway? regarding T.C.A cycle is true? (A) Glyceraldehyde-3-p (A) It is an anaerobic process (B) Glucose-6-p (B) It occurs in cytosol (C) Fructose-6-p (C) It contains no intermediates for Gluconeogen- (D) Fructose1, 6-bisphosphate esis 243. The ratio that approximates the number (D) It is amphibolic in nature of net molecule of ATP formed per mole 250. An responsible for of Glucose oxidized in presence of O2 to controlling the rate of T.C.A cycle is the net number formed in abscence of (A) Malate dehydrogenase O2 is (B) Isocitrate dehydrogenase (A) 4 : 1 (B) 10 : 2 (C) (C) 12 : 1 (D) 18 : 1 (D) Aconitase 244. The “Primaquin sensitivity types of haemolytic anaemia has been found to 251. The glycolysis is regulated by relate to reduced R.B.C activity of which (A) Hexokinase (B) Phosphofructokinase enzyme? (C) Pyruvate kinase (D) All of these (A) Pyruvate kinase deficiency 252. How many ATP molecules will be required (B) Glucose-6-phosphatase deficiency for conversion of 2-molecules of Lactic acid (C) Glucose-6-p dehydrogenase deficiency to Glucose? (D) Hexokinase deficiency (A) 2 (B) 4 245. Which of the following hormones is not (C) 8 (D) 6 involved in carbohydrate metabolism? 253. Which of the following enzyme is not (A) Cortisol (B) ACTH involved in HMP shunt? (C) Glucogen (D) Vasopressin (A) Glyceraldehyde-3-p dehydrogenase 246. involved in HMP shunt (B) Glucose-6-p-dehydrogenase are specific for (C) Transketolase + + (A) NADP (B) NAD (D) Phosphogluconate dehydrogenase (C) FAD (D) FMN 254. In presence of the following , 247. Which of the following enzymes in Glyco- pyruvate carboxylase converts pyruvate lytic pathway is inhibited by fluoride? to oxaloacetate: (A) Glyceraldehyde-3-p dehydrogenase (A) ATP, Protein and CO2 (B) (B) CO2 and ATP (C) Pyruvate kinase (C) CO2 (D) Enolase (D) Protein 248. Out of 24 mols of ATP formed in TCA cycle, 255. For conversion of oxaloacetate to 2 molecules of ATP can be formed at phosphoenol pyruvate, high energy “substrate level” by which of the molecule is required in the form of following reaction ? (A) GTP only (B) ITP only (A) Citric acid Isocitric acid → (C) GTP (or) ITP (D) None of these (B) Isocitrate→ Oxaloacetate (C) Succinic acid→ Fumarate 256. If the more negative standard reduction potential of a redox pair, the greater the (D) Succinylcat→ Succinic acid tendency to 20 MCQs IN BIOCHEMISTRY

(A) To lose electrons (C) The free energy change, ∆G°, is equal to the (B) To gain electrons standard free energy change, ∆G° (C) To lose/gain electrons (D) Keq is equal to 1 (D) To lose and gain electrons 264. An uncoupler of oxidative phosphoryla- tion such as dinitrophenol 257. Electron transport and phosphorylation can be uncoupled by compounds that (A) Inhibits electron transport and ATP synthesis increase the permeability of the inner (B) Allow electron transport to proceed without mitochondrial membrane to ATP synthesis (A) Electrons (B) Protons (C) Inhibits electron transport without impairment of ATP synthesis (C) Uncouplers (D) All of these (D) Specially inhibits cytochrome b

258. The more positive the E0, the greater the tendency of the oxidant member of that 265. All of the following statements about the enzymic complex that carries out the pair to synthesis of ATP during oxidative (A) Lose electrons phosphorylation are correct except (B) Gain electrons (A) It is located on the matrix side of the inner (C) Lose (or) gain electrons mitochondrial membrane (D) Lose and gain electrons (B) It is inhibited by oligomycin 259. The standard free energy of hydrolysis (C) It can exhibit ATPase activity of terminal phosphate group of ATP is (D) It can bind molecular O2 (A) –7,300 cal/mol (B) –8,300 cal/mol 266. Glucokinase (C) 10,000 cal/mol (D) +7,300 cal/mol (A) Is widely distributed and occurs in most mammalian tissues 260. The transport of a pair of electrons from (B) Has a high km for glucose and hence is NADH to O2 via the electron transport chain produces important in the phosphorylation of glucose primarily after ingestion of a carbohydrate (A) –52,580 cal (B) –50,580 cal rich meal (C) 21,900 cal (D) +52,580 cal (C) Is widely distributed in Prokaryotes 261. Sufficient energy required to produce 3 (D) None of these ATP from 3 ADP and 3 pi is 267. The reaction catalysed by phosphofruc- (A) –21,900 cal (B) 29,900 cal tokinase (C) 31,900 cal (D) 39,900 cal (A) Is activated by high concentrations of ATP and citrate 262. The free energy change, AG (B) Uses fruitose-1-phosphate as substrate (A) Is directly proportional to the standard free (C) Is the rate-limiting reaction of the glycolytic energy change, AG pathway (B) Is equal to zero at equilibrium (D) Is inhibited by fructose 2, 6-bisphosphate (C) Can only be calculated when the reactants and products are present at 1mol/1 268. Compared to the resting state, vigorously concentrations contracting muscle shows (D) Is equal to –RT in keq (A) An increased conversion of pyruvate to lactate (B) Decreased oxidation of pyruvate of CO and 263. Under standard conditions 2 water (A) The free energy change ∆G°, is equal to 0 (C) A decreased NADH/NAD+ ratio (B) The standard free energy change ∆G, is (D) Decreased concentration of AMP equal to 0 CARBOHYDRATES AND CARBOHYDRATE METABOLISM 21

269. Which one of the following would be 275. Pasteur effect is expected in pyruvate kinase deficiency? (A) Inhibition of glycolysis (A) Increased levels of lactate in the R.B.C (B) Oxygen is involved (B) Hemolytic anemia (C) Inhibition of enzyme phosphofructokinase (C) Decreased ratio of ADP to ATP in R.B.C (D) All of these (D) Increased phosphorylation of Glucose to Glucose-6-phosphate 276. How many ATPs are produced in the conversion of phosphoenol pyruvate to 270. Which one of the following statements citrate? concerning glucose metabolism is correct? (A) 1 (B) 2 (A) The conversion of Glucose to lactate occurs (C) 4 (D) 6 only in the R.B.C (B) Glucose enters most cells by a mechanism in 277. Reduced glutathione functions in R.B.Cs which Na+ and glucose are co-transported to (C) Pyruvate kinase catalyses an irreversible (A) Produce NADPH reaction (B) Reduce methemoglobin to hemoglobin (D) An elevated level of insulin leads to a (C) Produce NADH decreased level of fructose 2, 6-bisphosphate (D) Reduce oxidizing agents such as H2O2 in hepatocyte 278. is the precursor of 271. Which one of the following compounds (A) L-DOPA (B) Histamine cannot give rise to the net synthesis of Glucose? (C) (D) Throxine (A) Lactate (B) Glycerol 279. D-Mannose is present in some plant (C) α-ketoglutarate (D) Acetyl CoA products like 272. Which of the following reactions is unique (A) Resins (B) Pectins to gluconeogenesis? (C) Mucilage (D) Gums (A) Lactate Pyruvate 280. Galactose is a main constituent of (B) Phosphoenol pyruvate pyruvate (A) Milk sugar (B) Honey (C) Oxaloacetate phosphoenol pyruvate (C) Cane sugar (D) Chitin (D) Glucose-6-phosphate Fructose-6-phosphate 281. Glucosamine is an important constituent 273. The synthesis of glucose from pyruvate of by gluconeogenesis (A) Homopolysaccharide (A) Requires the participation of biotin (B) Heteropolysaccharide (B) Occurs exclusively in the cytosol (C) Mucopolysaccharide (C) Is inhibited by elevated level of insulin (D) Dextran (D) Requires oxidation/reduction of FAD 282. Glycogen is present in all body tissues 274. The conversion of pyruvate to acetyl CoA except and CO 2 (A) Liver (B) Brain (A) Is reversible (C) Kidney (D) Stomach (B) Involves the participation of lipoic acid 283. Iodine test is positive for starch, dextrin and (C) Depends on the coenzyme biotin (D) Occurs in the cytosol (A) Mucoproteins (B) Agar (C) Glycogen (D) Cellulose 22 MCQs IN BIOCHEMISTRY

284. The general formula for polysaccharide is 294. α−α−α−D-Glucose and β−β−β−D-glucose are related by (A) (C6H10O5)n (B) (C6H12C6)n (A) Epimers (B) Anomers (C) (C6H12O5)n (D) (C5H10O5)n (C) Multirotation (D) Ketoenol pair 285. Epimers of glucose is (A) Fructose (B) Galactose 295. The stable ring formation in D-Glucose (C) Ribose (D) Deoxyribose involves (A) C-1 and C-4 (B) C-1 and C-2 286. Human heart muscle contains (C) C-1 and C-5 (D) C-2 and C-5 (A) D-Arabinose (B) D-Ribose ++ (C) D-Xylose (D) L-Xylose 296. Reduction of Glucose with Ca in water produces 287. The intermediate n hexose monophos- phate shunt is (A) Sorbitol (B) Dulcitol (C) Mannitol (D) Glucuronic acid (A) D-Ribulose (B) D-Arabinose (C) D-xylose (D) D-Lyxose 297. Starch and glycogen are polymers of 288. On boiling Benedict’s solution is not (A) Fructose (B) Mannose reduced by (C) α−D-Glucose (D) Galactose (A) Sucrose (B) Lactose 298. Reducing ability of carbohydrates is due (C) Maltose (D) Fructose to 289. The distinguishing test between monosac- (A) Carboxyl group (B) Hydroxyl group charides and dissaccharide is (C) Enediol formation (D) Ring structure (A) Bial’s test (B) Seliwanoff’s test 299. Which of the following is not a polymer (C) Barfoed’s test (D) Hydrolysis test of glucose? 290. Barfoed’s solution is not reduced by (A) Amylose (B) Inulin (A) Glucose (B) Mannose (C) Cellulose (D) Dextrin (C) Sucrose (D) Ribose 300. Invert sugar is 291. Cori cycle is (A) Lactose (A) Synthesis of glucose (B) Mannose (B) reuse of glucose (C) Fructose (C) uptake of glycose (D) Hydrolytic product of sucrose (D) Both (A) & (B) 301 The carbohydrate reserved in human 292. Cane sugar is known as body is (A) Galactose (B) Sucrose (A) Starch (B) Glucose (C) Fructose (D) Maltose (C) Glycogen (D) Inulin 293. Which of the following is not reducing 302 A dissaccharide linked by α -1-4 Glycosi- sugar? deic linkages is (A) Lactose (B) Maltose (A) Lactose (B) Sucrose (C) Sucrose (D) Fructose (C) Cellulose (D) Maltose CARBOHYDRATES AND CARBOHYDRATE METABOLISM 23

ANSWERS 1. A 2. A 3. A 4. A 5. B 6. A 7. A 8. D 9. A 10. A 11. A 12. C 13. B 14. A 15. A 16. B 17. A 18. A 19. C 20. C 21. A 22. D 23. C 24. B 25. A 26. D 27. C 28. C 29. B 30. B 31. D 32. A 33. C 34. B 35. B 36. B 37. C 38. B 39. D 40. A 41. D 42. B 43. A 44. B 45. A 46. A 47. A 48. A 49. B 50. C 51. C 52. A 53. A 54. A 55. B 56. A 57. D 58. A 59. C 60. D 61. C 62. C 63. B 64. C 65. C 66. C 67. B 68. C 69. D 70. D 71. A 72. A 73. B 74. B 75. B 76. B 77. A 78. C 79. A 80. B 81. D 82. C 83. D 84. D 85. B 86. D 87. D 88. C 89. B 90. A 91. A 92. D 93. A 94. C 95. C 96. D 97. D 98. A 99. C 100. C 101. B 102. A 103. C 104. C 105. B 106. B 107. C 108. D 109. B 110. C 111. B 112. B 113. B 114. D 115. B 116. B 117. A 118. B 119. B 120. A 121. B 122. D 123. B 124. A 125. C 126. A 127. B 128. D 129. C 130. A 131. A 132. D 133. C 134. B 135. C 136. C 137. C 138. A 139. B 140. C 141. B 142. A 143. C 144. D 145. B 146. C 147. B 148. B 149. B 150. D 151. B 152. C 153. D 154. A 155. B 156. A 157. C 158. A 159. B 160. D 161. A 162. B 163. A 164. B 165. D 166. C 167. C 168. A 169. B 170. A 171. D 172. C 173. A 174. B 175. D 176. B 177. A 178. C 179. D 180. B 181. B 182. C 183. D 184. B 185. C 186. C 187. A 188. B 189. C 190. B 191. A 192. D 193. D 194. C 195. D 196. A 197. B 198. B 199. C 200. C 201. C 202. B 203. D 204. C 205. C 206. D 207. A 208. A 209. C 210. C 211. B 212. A 213. A 214. A 215. C 216. C 217. C 218. C 219. C 220. B 221. B 222.C 223. B 224. B 225. A 226. C 227. D 228. A 229. B 230. D 231. C 232. B 233. C 234. A 235. B 236. D 237. B 238. B 239. B 240. C 241. D 242. D 243. B 244. C 245. D 246. A 247. D 248. D 249. D 250. B 251. D 252. D 24 MCQs IN BIOCHEMISTRY

253. A 254. A 255. C 256. A 257. B 258. B 259. A 260. D 261. A 262. B 263. C 264. B 265. D 266. B 267. C 268. A 269. B 270. C 271. B 272. C 273. A 274. B 275. D 276. C 277. D 278. C 279. D 280. A 281. C 282. B 283. C 284. A 285. B 286. C 287. A 288. A 289. C 290. C 291. D 292. B 293. C 294. B 295. C 296. A 297. C 298. A 299. B 300. D 301. C 302. D

EXPLANATIONS FOR THE ANSWERS 7. A Polysaccharides are polymers of monosac- get dehydrated to form furfural (from pentoses) charides. They are of two types– hompolysac- or hydroxy methylfurfural (from hexoses) which charides that contain a single type of condense with α-naphthol to form a violet monosaccharide (e.g., starch, insulin, cellulose) coloured complex. and heteropolysaccharides with two or more 163. A Seliwanoff’s test: this is a specific test for different types of monosaccharides (e.g., heparin, ketohexoses. Concentrated hydrochloric acid chondroitin sulfate). dehydrates ketohexoses to form furfural 30. B Mutorotation refers to the change in the specific derivatives which condense with resorcinol to optical rotation representing the interconversion of give a cherry red complex. α- and β- anomers of D-glucose to an equilibrium. 187. A Rothera’s test: Nitroprosside in alkaline medium 48. A Starch is a polysaccharide composed of D- reacts with keto group of ketone bodies (acetone glucose units held together by α-glycosidic and acetoacetate) to form a purple ring. This bonds, (α 1→ 4 linkages; at branching points test is not given by β-hydroxybutyrate. α 1→ 6 linkages). 203. D Two specific transport systems are recognized 71. A Hyaluronic acid is the ground substance of for the entry of glucose into the cells. synovial fluid of joints. It serves as lubricants (a) Insulin-independent transport: This is a carrier and shock absorbant in joints. mediated uptake of glucose which is not 93. A The process of shifting a hydrogen atom from dependent on the hormone inslulin. This operates one carbon to another to produce enediols is in hepatocytes, erythrocytes and brain. referred to as tautomerization. (b) Insulin-dependent transport: This occurs in 117. A Mucopolysaccharides (commonly known as muscle and adipose tissue. glycosaminoglycans) are heteropolysaccharides 230. D Hexokinase and glucokinase are involved in composed of sugar derivatives (mainly amino the phosphorylation of glucose to glucose 6- sugars and uronic acids). The important phosphate. The enzyme hexokinase, present mucopolysaccharides include hyaluronic acid, in almost all the tissues, catalyses the heparin, chondroitin sulfate, dermatan sulfate phosphorylation of other hexose also (fructose, and keratan sulfate. mannose). It has low Km for substrates (about 141. B Molisch test: It is a general test for the detection 0.1 mM) and is inhibited by glucose 6-

of carbohydrates. The strong H2SO4 hydrolyses phosphate. In contrast, glucokinase is present carbohydrates (poly- and disaccharides) to lib- in liver, catalyses the phosphorylation of only

erate monosaccharides. The monosaccharides glucose, has high Km for glucose (10 mM) CARBOHYDRATES AND CARBOHYDRATE METABOLISM 25

and is not inhibited by glucose 6-phosphate. referred to as Pasteur effect. This is due to 251. D The three enzymes namely hexokinase (or inhibition of the enzyme phosphofructokinase glucokinase), phosphofructokinase and by ATP and citrate (formed in the presence of pyruvate kinase, catalyzing the irreversible O2) reactions regulate glycolysis. Among these, 291. D The cycle involving the synthesis of glucose in phosphofructokinase is the most regulatory. It liver from the skeletal muscle lactate and the is an allosteric enzyme inhibited by ATP, citrate reuse of glucose thus synthesized by the muscle and activated by AMP and Pi. for energy purposes is known as Cori Cycle. 275. D The inhibition of glycolysis by oxygen is This page intentionally left blank CHAPTER 3

PPPROROROTEINSTEINSTEINS ANDANDAND PPPROROROTEINTEINTEIN MMMETETETABOLISMABOLISMABOLISM

1. All proteins contain the (D) All amino acids contain negatively charged (A) Same 20 amino acids side chains (B) Different amino acids 6. pH (isoelectric pH) of alanine is (C) 300 Amino acids occurring in nature (A) 6.02 (B) 6.6 (D) Only a few amino acids (C) 6.8 (D) 7.2 2. Proteins contain 7. Since the pK values for aspartic acid are (A) Only L- α - amino acids 2.0, 3.9 and 10.0, it follows that the (B) Only D-amino acids isoelectric (pH) is (C) DL-Amino acids (A) 3.0 (B) 3.9 (D) Both (A) and (B) (C) 5.9 (D) 6.0 3. The optically inactive is 8. Sulphur containing amino acid is (A) (B) Serine (A) (B) (C) (D) (C) Valine (D) Asparagine 4. At neutral pH, a mixture of amino acids 9. An example of sulphur containing amino in solution would be predominantly: acid is (A) Dipolar ions (A) 2-Amino-3-mercaptopropanoic acid (B) Nonpolar molecules (B) 2-Amino-3-methylbutanoic acid (C) Positive and monovalent (C) 2-Amino-3-hydroxypropanoic acid (D) Hydrophobic (D) Amino acetic acid 5. The true statement about solutions of 10. All the following are sulphur containing amino acids at physiological pH is amino acids found in proteins except (A) All amino acids contain both positive and (A) (B) Cystine negative charges (C) Methionine (D) Threonine (B) All amino acids contain positively charged 11. An aromatic amino acid is side chains (C) Some amino acids contain only positive (A) (B) Tyrosine charge (C) Taurine (D) 28 MCQs IN BIOCHEMISTRY

12. The functions of plasma are 21. An amino acid that does not form an ααα- (A) Osmosis (B) Transport helix is (C) Immunity (D) both (A )and (B) (A) Valine (B) 13. Amino acid with side chain containing (C) Tyrosine (D) basic groups is 22. An amino acid not found in proteins is (A) 2-Amino 5-guanidovaleric acid (A) β-Alanine (B) Proline (B) 2-Pyrrolidine carboxylic acid (C) Lysine (D) (C) 2-Amino 3-mercaptopropanoic acid 23. In mammalian tissues serine can be a (D) 2-Amino propanoic acid biosynthetic precursor of 14. An example of ααα-amino acid not present (A) Methionine (B) Glycine in proteins but essential in mammalian (C) Tryptophan (D) Phenylalanine metabolism is 24. A vasodilating compound is produced by (A) 3-Amino 3-hydroxypropanoic acid the decarboxylation of the amino acid: (B) 2-Amino 3-hydroxybutanoic acid (A) Arginine (B) Aspartic acid (C) 2-Amino 4-mercaptobutanoic acid (C) Glutamine (D) Histidine (D) 2-Amino 3-mercaptopropanoic acid 25. Biuret reaction is specific for 15. An essential amino acid in man is (A) –CONH-linkages (B) –CSNH2 group (A) Aspartate (B) Tyrosine (C) –(NH)NH2 group (D) All of these (C) Methionine (D) Serine 26. Sakaguchi’s reaction is specific for 16. Non essential amino acids (A) Tyrosine (B) Proline (A) Are not components of tissue proteins (C) Arginine (D) Cysteine (B) May be synthesized in the body from essential amino acids 27. Million-Nasse’s reaction is specific for the amino acid: (C) Have no role in the metabolism (D) May be synthesized in the body in diseased (A) Tryptophan (B) Tyrosine states (C) Phenylalanine (D) Arginine

17. Which one of the following is semi- 28. Ninhydrin with evolution of CO2 forms a essential amino acid for humans? blue complex with (A) Valine (B) Arginine (A) Peptide bond (B) α -Amino acids (C) Lysine (D) Tyrosine (C) Serotonin (D) Histamine 18. An example of polar amino acid is 29. The most of the ultraviolet absorption of proteins above 240 nm is due to their (A) Alanine (B) Leucine content of (C) Arginine (D) Valine (A) Tryptophan (B) Aspartate 19. The amino acid with a nonpolar side chain (C) Glutamate (D) Alanine is 30. Which of the following is a dipeptide? (A) Serine (B) Valine (C) Asparagine (D) Threonine (A) Anserine (B) Glutathione (C) Glucagon (D) -Lipoprotein 20. A ketogenic amino acid is β (A) Valine (B) Cysteine 31. Which of the following is a tripeptide? (C) Leucine (D) Threonine (A) Anserine (B) Oxytocin (C) Glutathione (D) Kallidin PROTEINS AND PROTEIN METABOLISM 29

32. A peptide which acts as potent smooth 43. The amino acid from which synthesis of muscle hypotensive agent is the protein of takes place is (A) Glutathione (B) Bradykinin (A) Alanine (B) Methionine (C) Tryocidine (D) Gramicidin-s (C) Proline (D) Hydroxyproline 33. A tripeptide functioning as an important 44. In one molecule of albumin the number reducing agent in the tissues is of amino acids is (A) Bradykinin (B) Kallidin (A) 510 (B) 590 (C) Tyrocidin (D) Glutathione (C) 610 (D) 650 34. An example of metalloprotein is 45. Plasma proteins which contain more than (A) Casein (B) 4% hexosamine are (C) (D) Salmine (A) Microglobulins (B) Glycoproteins (C) Mucoproteins (D) Orosomucoids 35. is an example of 46. After releasing O at the tissues, (A) Lipoprotein (B) Phosphoprotein 2 hemoglobin transports (C) Metalloprotein (D) Chromoprotein (A) CO2 and protons to the lungs 36. An example of chromoprotein is (B) O2 to the lungs (A) Hemoglobin (B) Sturine (C) CO2 and protons to the tissue (C) Nuclein (D) Gliadin (D) Nutrients 37. An example of scleroprotein is 47. Ehlers-Danlos syndrome characterized by (A) Zein (B) Keratin hypermobile joints and skin abnormalities (C) Glutenin (D) Ovoglobulin is due to (A) Abnormality in gene for procollagen 38. Casein, the milk protein is (B) Deficiency of (A) Nucleoprotein (B) Chromoprotein (C) Deficiency of prolyl hydroxylase (C) Phosphoprotein (D) Glycoprotein (D) Deficiency of 39. An example of phosphoprotein present 48. Proteins are soluble in in egg yolk is (A) Anhydrous acetone(B) Aqueous alcohol (A) Ovoalbumin (B) Ovoglobulin (C) Anhydrous alcohol (D) Benzene (C) Ovovitellin (D) Avidin 49. A cereal protein soluble in 70% alcohol 40. A simple protein found in the nucleopro- but insoluble in water or salt solution is teins of the sperm is (A) Glutelin (B) Protamine (A) Prolamine (B) Protamine (C) Albumin (D) Gliadin (C) Glutelin (D) 50. Many globular proteins are stable in 41. Histones are solution inspite they lack in (A) Identical to protamine (A) Disulphide bonds (B) Hydrogen bonds (B) Proteins rich in lysine and arginine (C) Salt bonds (D) Non polar bonds (C) Proteins with high molecular weight (D) Insoluble in water and very dilute acids 51. The hydrogen bonds between peptide linkages of a protein molecules are inter- 42. The protein present in hair is fered by (A) Keratin (B) (A) Guanidine (B) Uric acid (C) Myosin (D) Tropocollagen (C) Oxalic acid (D) Salicylic acid 30 MCQs IN BIOCHEMISTRY

52. Globular proteins have completely folded, 60. At the lowest energy level ααα-helix of coiled polypeptide chain and the axial polypeptide chain is stabilised ratio (ratio of length to breadth) is (A) By hydrogen bonds formed between the H of (A) Less than 10 and generally not greater than peptide N and the carbonyl O of the residue 3–4 (B) Disulphide bonds (B) Generally 10 (C) Non polar bonds (C) Greater than 10 and generally 20 (D) Ester bonds (D) Greater than 10 61. Both ααα-helix and βββ-pleated sheet confor- 53. Fibrous proteins have axial ratio mation of proteins were proposed by (A) Less than 10 (A) Watson and Crick (B) Less than 10 and generally not greater than (B) Pauling and Corey 3–4 (C) Waugh and King (C) Generally 10 (D) Y.S.Rao (D) Greater than 10 62. The primary structure of fibroin, the 54. Each turn of α -helix contains the amino principal protein of silk worm fibres acid residues (number): consists almost entirely of (A) 3.6 (B) 3.0 (A) Glycine (B) Aspartate (C) 4.2 (D) 4.5 (C) Keratin (D) Tryptophan

55. Distance traveled per turn of α−α−α−helix in 63. Tertiary structure of a protein describes nm is (A) The order of amino acids (A) 0.53 (B) 0.54 (B) Location of disulphide bonds (C) 0.44 (D) 0.48 (C) Loop regions of proteins (D) The ways of 56. Along the ααα-helix each amino acid residue advances in nm by 64. In a protein molecule the disulphide bond (A) 0.15 (B) 0.10 is not broken by (C) 0.12 (D) 0.20 (A) Reduction 57. The number of helices present in a (B) Oxidation molecule is (C) Denaturation (A) 1 (B) 2 (D) X-ray diffraction (C) 3 (D) 4 65. The technique for purification of proteins that can be made specific for a given 58. In proteins the ααα-helix and βββ-pleated sheet protein is are examples of (A) Gel filtration chromotography (A) Primary structure (B) Secondary structure (B) Ion exchange chromatography (C) Tertiary structure (D) Quaternary structure (C) Electrophoresis 59. The a-helix of proteins is (D) Affinity chromatography (A) A pleated structure 66. Denaturation of proteins results in (B) Made periodic by disulphide bridges (A) Disruption of primary structure (C) A non-periodic structure (B) Breakdown of peptide bonds (D) Stabilised by hydrogen bonds between NH and CO groups of the main chain (C) Destruction of hydrogen bonds (D) Irreversible changes in the molecule PROTEINS AND PROTEIN METABOLISM 31

67. Ceruloplasmin is 77. A lipoprotein inversely related to the incidence of coronary artherosclerosis is (A) α1-globulin (B) α2-globulin (C) β-globulin (D) None of these (A) VLDL (B) IDL 68. The lipoprotein with the fastest electro- (C) LDL (D) HDL phoretic mobility and the lowest triglyc- 78. The primary biochemical lesion in ho- eride content is mozygote with familial hypercholester- (A) Chylomicron (B) VLDL olemia (type IIa) is (C) IDL (D) HDL (A) Loss of feed back inhibition of HMG 69. The lipoprotein associated with activation of LCAT is (B) Loss of apolipoprotein B (A) HDL (B) LDL (C) Increased production of LDL from VLDL (C) VLDL (D) IDL (D) Functional deficiency of plasma membrane receptors for LDL 70. The apolipoprotein which acts as activator of LCAT is 79. In abetalipoproteinemia, the biochemical (A) A-I (B) A-IV defect is in (C) C-II (D)D (A) Apo-B synthesis 71. The apolipoprotein which acts as actiator (B) Lipprotein activity of extrahepatic lipoprotein is (C) Cholesterol ester (A) Apo-A (B) Apo-B (D) LCAT activity (C) Apo-C (D) Apo-D 80. Familial hypertriaacylglycerolemia is 72. The apolipoprotein which forms the associated with integral component of chylomicron is (A) Over production of VLDL (A) B-100 (B) B-48 (B) Increased LDL concentration (C) C (D)D (C) Increased HDL concentration 73. The apolipoprotein which from the (D) Slow clearance of chylomicrons integral component of VLDL is 81. For synthesis of prostaglandins, the (A) B-100 (B) B-48 essential fatty acids give rise to a fatty (C) A (D)D acid containing 74. The apolipoprotein which acts as (A) 12 carbon atoms (B) 16 carbon atoms for LDL receptor is (C) 20 carbon atoms (D) 24 carbon atoms (A) B-48 (B) B-100 82. All active prostaglandins have at least one (C) A (D)C double bond between positions 75. Serum LDL has been found to be increased (A) 7 and 8 (B) 10 and 11 in (C) 13 and 14 (D) 16 and 17 (A) Obstructive jaundice 83. Normal range of plasma total phospho- (B) Hepatic jaundice lipids is (C) Hemolytic jaundice (D) Malabsorption syndrome (A) 0.2–0.6 mmol/L (B) 0.9–2.0 mmol/L (C) 1.8–5.8 mmol/L (D) 2.8–5.3 mmol/L 76. A lipoprotein associated with high

incidence of coronary atherosclerosis is 84. HDL2 have the density in the range of (A) LDL (B) VLDL (A) 1.006–1.019 (B) 1.019–1.032 (C) IDL (D) HDL (C) 1.032–1.063 (D) 1.063–1.125 32 MCQs IN BIOCHEMISTRY

85. βββ-lipoproteins have the density in the 96 acts on denatured proteins to range of produce (A) 0.95–1.006 (B) 1.006–1.019 (A) Proteoses and peptones (C) 1.019–1.063 (D) 1.063–1.125 (B) Polypeptides (C) Peptides 86. IDL have the density in the range of (D) Dipeptides (A) 0.95–1.006 (B) 1.006–1.019 97. converts casein to paracasein in (C) 1.019–1.032 (D) 1.032–1.163 presence of 87. Aspirin inhibits the activity of the enzyme: (A) Ca++ (B) Mg++ + + (A) (B) (C) Na (D) K

(C) Phospholipae A1 (D) Phospholipase A2 98. An expopeptidase is 88. A ’suicide enzyme’ is (A) (B) (C) (D) Elastase (A) Cycloxygenase (B) Lipooxygenase

(C) (D) Phospholipase A2 99. The enzyme trypsin is specific for peptide bonds of 89. In adipose tissue prostaglandins (A) Basic amino acids decrease (B) Acidic amino acids (A) Lipogenesis (B) Lipolysis (C) Aromatic amino acids (C) Gluconeogenesis (D) Glycogenolysis (D) Next to small amino acid residues 90 The optimal pH for the enzyme pepsin is 100. Chymotrypsin is specific for peptide bonds (A) 1.0–2.0 (B) 4.0–5.0 containing (C) 5.2–6.0 (D) 5.8–6.2 (A) Uncharged amino acid residues (B) Acidic amino acids 91. Pepsinogen is converted to active pepsin (C) Basic amino acid by (D) Small amino acid residues (A) HCl (B) Bile salts (C) Ca++ (D) Enterokinase 101. The end product of protein digestion in G.I.T. is 92. The optimal pH for the enzyme rennin is (A) Dipeptide (B) Tripeptide (A) 2.0 (B) 4.0 (C) Polypeptide (D) Amino acid (C) 8.0 (D) 6.0 102. Natural L-isomers of amino acids are 93. The optimal pH for the enzyme trypsin is absorbed from intestine by (A) 1.0–2.0 (B) 2.0–4.0 (A) Passive diffusion (B) Simple diffusion (C) 5.2–6.2 (D) 5.8–6.2 (C) Faciliated diffusion(D) Active process 103. Abnormalities of blood clotting are 94. The optimal pH for the enzyme chymo- trypsin is (A) Haemophilia (B) Christmas disease (C) Gout (D) Both (A) and (B) (A) 2.0 (B) 4.0 (C) 6.0 (D) 8.0 104. An important reaction for the synthesis of amino acid from carbohydrate 95 is converted to active trypsin intermediates is transamination which by requires the cofactor: (A) Enterokinase (B) Bile salts (A) Thiamin (B) Riboflavin (C) HCl (D) Mg++ (C) Niacin (D) Pyridoxal phosphate PROTEINS AND PROTEIN METABOLISM 33

105. The main sites for oxidative deamination 113. Control of involves the enzyme: are (A) Carbamoyl phosphate synthetase (A) Liver and kidney (B) transcarbamoylase (B) Skin and pancreas (C) Argininosuccinase (C) Intestine and mammary gland (D) (D) Lung and spleen 114. Transfer of the carbamoyl moiety of 106. A positive nitrogen balance occurs carbamoyl phosphate to ornithine is catalysed by a liver mitochondrial enzyme: (A) In growing infant (A) Carbamoyl phosphate synthetase (B) Following surgery (B) Ornithine transcarbamoylase (C) In advanced cancer (C) N-acetyl glutamate synthetase (D) In kwashiorkar (D) N-acetyl glutamate hydrolase 107. The main site of urea synthesis in mam- 115. A compound serving a link between citric mals is acid cycle and urea cycle is (A) Liver (B) Skin (A) Malate (B) Citrate (C) Intestine (D) Kidney (C) Succinate (D) Fumarate 108. The enzymes of urea synthesis are found 116. The 2 nitrogen atoms in urea are in contributed by (A) Mitochondria only (A) Ammonia and glutamate (B) Cytosol only (B) Glutamine and glutamate (C) Both mitochondria and cytosol (C) Ammonia and aspartate (D) Nucleus (D) Ammonia and alanine

109. The number of ATP required for urea 117. In carcinoid syndrome the argentaffin synthesis is tissue of the abdominal cavity over- produce (A) 0 (B) 1 (A) Serotonin (B) Histamine (C) 2 (D) 3 (C) Tryptamine (D) Tyrosine 110. Most of the ammonia released from L-ααα- 118. Tryptophan could be considered as amino acids reflects the coupled action of precursor of and (A) Melanotonin (B) Thyroid hormones (A) L- (C) Melanin (D) Epinephrine (B) L-amino acid oxidase (C) Histidase 119. Conversion of tyrosine to dihydroxyphe- nylalanine is catalysed by tyrosine hy- (D) Serine dehydratase droxylase which requires 111. In urea synthesis, the amino acid function- (A) NAD (B) FAD ing solely as an : (C) ATP (D) Tetrahydrobiopterin (A) N-acetyl glutamate (B) Ornithine 120. The rate limiting step in the biosynthesis (C) (D) Arginine of catecholamines is 112. The enzyme carbamoyl phosphate (A) Decarboxylation of dihydroxyphenylalanine synthetase requires (B) Hydroxylation of phenylalanine (A) Mg++ (B) Ca++ (C) Hydroxylation of tyrosine (C) Na+ (D) K+ (D) Oxidation of dopamine 34 MCQs IN BIOCHEMISTRY

121. The enzyme dopamine βββ-oxidase which 130 Chemical score of protein zein is catalyses conversion of dopamine to (A) 0 (B) 57 norepinephrine requires (C) 60 (D) 70 (A) Vitamin A (B) Vitamin C 131. Biological value of egg white protein is (C) Vitamin E (D) Vitamin B12 (A) 94 (B) 83 122. In humans the sulphur of methionine and (C) 85 (D) 77 cysteine is excreted mainly as (A) Ethereal sulphate 132. Net protein utilisation of egg protein is (B) Inorganic sulphate (A) 75% (B) 80% (C) Sulphites (C) 91% (D) 72% (D) Thioorganic compound 133. Net protein utilization of milk protein is 123. Small amount of urinary oxalates is (A) 75% (B) 80% contributed by the amino acid: (C) 86% (D) 91% (A) Glycine (B) Tyrosine 134. A limiting amino acid is an essential (C) Alanine (D) Serine amino acid 124. The amino acid which detoxicated benzoic (A) That is most deficient in proteins acid to form hippuric acid is (B) That is most excess in proteins (A) Glycine (B) Alanine (C) That which increases the growth (C) Serine (D) (D) That which increases the weight gain

125. The amino acids involved in the synthesis 135. The limiting amino acid of rice is of creatin are (A) Lysine (B) Tryptophan (A) Arginine, glycine, active methionine (C) Phenylalanine (D) Tyrosine (B) Arginine, alanine, glycine 136. The limiting amino acid of fish proteins is (C) Glycine, lysine, methionine (D) Arginine, lysine, methionine (A) Tryptophan (B) Cysteine (C) Lysine (D) Threonine 126. Chemical score of egg proteins is consid- ered to be 137. Pulses are deficient in (A) 100 (B) 60 (A) Lysine (B) Threonine (C) 50 (D) 40 (C) Methionine (D) Tryptophan

127. Chemical score of milk proteins is 138. A trace element deficient in the milk is (A) 70 (B) 65 (A) Magnesium (B) Copper (C) 60 (D) 40 (C) Zinc (D) Chloride

128. Chemical score of proteins of bengal gram 139. A conjugated protein present in the egg is yolk is (A) 70 (B) 60 (A) Vitellin (B) Livetin (C) 44 (D) 42 (C) Albuminoids (D) Ovo-mucoid

129. Chemical score of protein gelatin is 140. The chief protein of cow’s milk is (A) 0 (B) 44 (A) Albumin (B) Vitellin (C) 57 (D) 60 (C) Livetin (D) Casein PROTEINS AND PROTEIN METABOLISM 35

141. A water soluble vitamin deficient in egg is 153. In the total proteins, the percentage of (A) Thiamin (B) Ribofalvin albumin is about (C) Ascrobic acid (D) Cobalamin (A) 20–40 (B) 30–45 (C) 50–70 (D) 80–90 142. Pulses are rich in 154. In the total proteins percentage of (A) Lysine (B) Methionine α1 globulin is about (C) Tryptophan (D) Phenylalanine (A) 0.2–1.2% (B) 1.2–2.0% 143. Milk is deficient in (C) 2.4–4.4% (D) 5.0–10.0% (A) Vitamin B (B) Vitamin B 1 2 155. In the total proteins the percentage of (C) Sodium (D) Potassium γ globulin is about 144. Milk is deficient in (A) 2.4–4.4% (B) 10.0–21.0% (A) Calcium (B) Iron (C) 6.1–10.1% (D) 1.2–2.0% (C) Sodium (D) Potassium 156. Most frequently the normal albumin 145. When net protein utilization (NPU) is low, globulin ratioratio (A : G) is the requirements for proteins are (A) 1.0 : 0.8 (B) 1.5 : 1.0 (A) High (B) Moderate (C) 2.0 : 1.0 (D) 2.4 : 1.0 (C) Low (D) Supplementary 157. In Thymol turbidity test the protein 146. Protein content of human milk is about involved is mainly (A) Albumin (B) -Globulin (A) 1.4% (B) 2.4% α1

(C) 3.4% (D) 4.4% (C) α2-Globulin (D) β Globulin 147. Protein content of cow’s milk is about 158. In quaternary structure, subunits are (A) 2.5% (B) 3.5% linked by (C) 4.5% (D) 5.5% (A) Peptide bonds (B) Disulphide bonds (C) Covalent bonds (D) Non-covalent bonds 148. Protein content of soyabean is about (A) 30% (B) 40% 159. Molecular weight of human albumin is about (C) 50% (D) 60% (A) 156,000 (B) 90,000 149. Lipid content of egg white is (C) 69,000 (D) 54,000 (A) 12% (B) 33% 160. At isoelectric pH, an amino acid exists as (C) 10–11% (D) Traces (A) Anion (B) Cation 150. The recommended daily allowance (RDA) (C) Zwitterion (D) None of these of proteins for an adult man is 161. A disulphide bond can be formed (A) 70 gms (B) 50 gms between (C) 40 gms (D) 30 gms (A) Two methionine residues 151. The basic amino acids are (B) Two cysteine residues (A) Lysine (B) Bile acids (C) A methionine and a cysteine residue (C) Glycine (D) Alanine (D) All of these 152. The daily caloric requirement for the 162 A coagulated protein is normal adult female is about (A) Insoluble (A) 1500 (B) 2100 (B) Biologically non-functional (C) 2500 (D) 2900 (C) Unfolded (D) All of the above 36 MCQs IN BIOCHEMISTRY

163. At a pH below the isoelectric point, an (C) Chaperonins amino acid exists as (D) All of these

(A) Cation 172. Primary structure of a protein is formed by (B) Anion (A) Hydrogen bonds (B) Peptide bonds (C) Zwitterion (C) Disulphide bonds (D) All of these (D) Undissociated molecule 173. ααα-Helix is formed by 164. An amino acid having a hydrophilic side chain is (A) Hydrogen bonds (B) Hydrophobic bonds (A) Alanine (B) Proline (C) Electrostatic bonds (C) Methionine (D) Serine (D) Disulphide bonds 165. An amino acid that does not take part in ααα helix formation is 174. Glutelins are present in (A) Histidine (B) Tyrosine (A) Milk (B) Eggs (C) Proline (D) Tryptophan (C) Meat (D) Cereals

166. A protein rich in cysteine is 175. Aromatic amino acids can be detected by (A) Collagen (B) Keratin (A) Sakaguchi reaction (C) Haemoglobin (D) Gelatin (B) Millon-Nasse reaction (C) Hopkins-Cole reaction 167. Primary structure of proteins can be (D) Xanthoproteic reaction determined by the use of (A) Electrophoresis (B) Chromatography 176. Two amino groups are present in (C) Ninhydrin (D) Sanger’s reagent (A) Leucine (B) Glutamate (C) Lysine (D) Threonine 168. Electrostatic bonds can be formed between the side chains of 177. During denaturation of proteins, all of the (A) Alanine and leucine following are disrupted except (B) Leucine and valine (A) Primary structure (B) Secondary structure (C) Asparate and glutamate (C) Tertiary structure (D) Quaternary structure (D) Lysine and aspartate 178. All the following are branched chain 169. Sanger’s reagent contains amino acids except (A) Phenylisothiocyanate (A) (B) Alanine (B) Dansyl chloride (C) Leucine (D) Valine (C) 1-Fluoro-2, 4-dinitrobenzene 179. An –OH group is present in the side chain of (D) Ninhydrin (A) Serine (B) Arginine 170. The most abundant protein in mammals is (C) Lysine (D) Proline (A) Albumin (B) Haemoglobin 180. Edman’s reagent contains (C) Collagen (D) Elastin (A) Phenylisothiocyanate 171. Folding of newly synthesized proteins is (B) 1-Fluoro-2, 4-dinitrobenzene accelerated by (C) Dansyl Chloride (A) Protein disulphide isomerase (D) tBOC azide (B) Prolyl cis-trans isomerase PROTEINS AND PROTEIN METABOLISM 37

181. Edman’s reaction can be used to 190. Apolipoproteins C-I, C-II and C-III are (A) Determine the number of tyrosine residues in present in a protein (A) Chylomicrons (B) VLDL (B) Determine the number of aromatic amino acid (C) HDL (D) All of these residues in a protein (C) Determine the amino acid sequence of a 191. Apolipoprotiens C-I, C-II and C-III are protein present in all of the following except (D) Hydrolyse the peptide bonds in a protein (A) Chylomicrons (B) VLDL 182. Inherited deficiency of β−β−β−glucosidase causes (C) LDL (D) HDL (A) Tay-Sachs disease 192. Apolipoprotein A-I acts as (B) Metachromatic leukodystrophy (A) Enzyme activator (B) Ligand for receptor (C) Gaucher’s disease (C) Both (A) and (B) (D) None of these (D) Multiple sclerosis 193. Apolipoprotien B-100 acts as 183. Tay-Sachs disease results from inherited (A) Enzyme activator (B) Ligand for receptor deficiency of (C) Both (A) and (B) (D) None of these (A) Arylsulphatase A (B) A 194. Apolipoprotein C-II is an activator of (C) Sphingomyelinase (A) Lecithin cholesterola acyl transferase (D) (B) (C) Extrahepatic 184. The largest alpolipoprotein is (D) Hepatic lipoprotein lipase (A) Apo E (B) Apo B-48 (C) Apo B-100 (D) Apo A-I 195. Nascent chylomicron receives apolipopro- teins C and E from 185. Apolipoprotein B-100 is synthesised in (A) VLDL remnant (B) VLDL (A) Adipose tissue (B) Liver (C) LDL (D) HDL (C) Intestine (D) Liver and intestine 196. Terminal transferase 186. Apolipoprotein B-48 is synthesized in (A) Removes nucleotides from 3’ end (A) Adipose tissue (B) Liver (B) Adds nucleotides at 3’ end (C) Intestine (D) Liver and intestine (C) Removes nucleotides from 3’end 187. Apolipoproteins A-I and A-II are present (D) Adds nucleotides at 3’end in 197. S1 hydrolyses (A) LDL only (B) LDL and VLDL (A) DNA of somatic cells (C) HDL only (B) DNA of sperms (D) HDL and chylomicrons (C) Any double stranded DNA (D) Any single stranded DNA 188. Apolipoprotein B-48 is present in 198. Positive nitrogen balance is seen in (A) Chylomicrons (B) VLDL (C) LDL (D) HDL (A) Starvation (B) Wasting diseases 189. Apolipoprotein B-100 is present in (C) Growing age (A) Chylomicrons (B) VLDL only (D) Intestinal malabsorption (C) LDL only (D) VLDL and LDL 38 MCQs IN BIOCHEMISTRY

199. Alanine can be synthesized from 207. All the following statement about (A) Glutamate and α-ketoglutarate hydroxyproline are true except (B) Pyruvate and glutamate (A) There is no codon for hydroxyproline (C) Pyruvate and α-ketoglutarate (B) It is present in large amounts in collagen (D) Asparate and α-ketoglutarate (C) Free proline cannot be hydroxylated to hydroxyproline 200. All of the following are required for (D) Hydroxylation of proline residues is catalysed synthesis of alanine except by a (A) Pyruvate (B) α-ketoglutarate 208. All of the following are required for (C) Glutamate (D) Pyridoxal phosphate hydroxylation of proline residues except 201. All of the following statements about (A) Ascorbic acid (B) Glutamate aspartate are true except (C) Ferrous ions (D) Molecular oxygen (A) It is non-essential amino acid 209. Cysteine can be synthesized from (B) It is a dicarboxylic amino acid methionine and (C) It can be synthesized from pyruvate and glutamate (A) Serine (B) Homoserine (D) It can be converted into asparagine (C) (D) Threonine 202. Glycine can be synthesized from 210. Methionine is synthesized in human body from (A) Serine (B) Choline (C) Betaine (D) All of these (A) Cysteine and homoserine (B) Homocysteine and serine 203. All of the following are required for (C) Cysteine and serine synthesis of glutamine except (D) None of these (A) Glutamate (B) Ammonia 211. Hydroxylation of phenylalanine requires all of the following except (C) Pyridoxal phosphate (D) ATP (A) Phenylalanine hydroxylase (B) Tetrahydrobiopterin 204. A coenzyme required for the synthesis of (C) NADH glycine from serine is (D) Molecular oxygen (A) ATP (B) Pyridoxal phosphate 212. Non-Protein amino acids are (C) Tetrahydrofolate (A) Ornithine (D) NAD (B) β-alanine (C) γ-amino butyric acid 205. All of the following statements about proline are true except (D) All of these (A) It is an imino acid 213. The amino acid that undergoes oxidative (B) It can be synthesized from glutamate deamination at significant rate is (C) It can be catabolised to glutamate (A) Alanine (B) Aspartate (D) Free proline can be hydroxylated to (C) Glutamate (D) Glutamine hydroxyproline 214. Allosteric inhibitor of glutamate dehydro- 206. A protein rich in hydroxyproline is genase is (A) Prolamin (B) Procollagen (A) ATP (B) ADP (C) Collagen (D) Proinsulin (C) AMP (D)GMP PROTEINS AND PROTEIN METABOLISM 39

215. Allsoteric activator of glutamate dehydro- (A) Synthesis of carbamoyl phosphate and genase is citrulline (A) ATP (B) GTP (B) Synthesis of citrulline and argininosuccinate (C) ADP and GDP (D) AMP and GMP (C) Synthesis of argininosuccinate and arginine (D) Synthesis of carbamoyl phosphate and 216. Free ammonia is released during argininosuccinate (A) Oxidative deamination of glutamate 224. Daily excretion of nitrogen by an adult (B) Catabolism of purines man is about (C) Catabolism of pyrimidines (A) 15–20 mg (B) 1.5–2 gm (D) All of these (C) 5–10 gm (D) 15–20 gm 217. An organ which is extremely sensitive to 225. Maple syrup urine diseases is an inborn ammonia toxicity is error of metabolism of (A) Liver (B) Brain (A) Sulphur-containing amino acids (C) Kidney (D) Heart (B) Aromatic amino acids 218. Ammonia is transported from muscles to (C) Branched chain amino acids liver mainly in the form of (D) Dicarboxylic amino acids (A) Free ammonia (B) Glutamine 226. Cystinuria results from inability to (C) Asparagine (C) Alanine (A) Metabolise cysteine 219. The major site of urea synthesis is (B) Convert cystine into cysteine (C) Incorporate cysteine into proteins (A) Brain (B) Kidneys (D) Reabsorb cystine in renal tubules (C) Liver (D) Muscles 227. The defective enzyme in histidinemia is 220. Carbamoyl phosphate required for urea synthesis is formed in (A) Histidine carboxylase (B) (A) Cytosol (B) Mitochondria (C) Histidase (C) Both (A) and (B) (D) None of these (D) Histidine oxidase 221. Cytosolic and mitochondrial carbamoyl 228. All the following statements about phosphate synthetase have the following phenylketonuria are correct except similarity: (A) Phenylalanine cannot be converted into (A) Both use ammonia as a substance tyrosine (B) Both provide carbamoyl phosphate for urea (B) Urinary excretion of phenylpyruvate and synthesis phenyllactate is increased (C) Both require N-acetylglutamate as an (C) It can be controlled by giving a low- activator phenylalanine diet (D) Both are allosteric enzymes (D) It leads to decreased synthesis of thyroid 222. The following enzyme of urea cycle is hormones, catecholamines and melanin present in cytosol: 229. All the following statements about (A) Argininosuccinic acid synthetase albinism are correct except (B) Argininosuccinase (A) () is absent or (C) Arginase deficient in melanocytes (D) All of these (B) Skin is hypopigmented (C) It results in mental retardation 223. ATP is required in following reactions of (D) Eyes are hypopigmented urea cycle: 40 MCQs IN BIOCHEMISTRY

230. Glycine is not required for the formation themselves of (C) When combined with some other large (A) Taurocholic acid (B) molecule, they can elicit an immune response (C) Purines (D) Pyrimidines (D) Once an immune response develops, the free hapten can be recognized by the antibody 231. Histamine is formed from histidine by 238. Antigens and haptens have the following (A) Deamination (B) Dehydrogenation similarity: (C) Decarboxylation (D) Carboxylation (A) They have high molecular weights 232. DOPA is an intermediate in the synthesis (B) They can elicit immune response by themselves of (C) They can elicit an immune response only in (A) Thyroid hormones association with some other large molecule (B) Catecholamines (D) Once an immune response develops, free (C) Melanin antigen and free hapten can be recognized by the antibody (D) Catecholamines and melanin 239. The minimum number of polypeptide 233. All the following statements about pepsin chains in an immunoglobulin is are correct except (A) Two (B) Four (A) It is smaller than pepsinogen (C) Five (D) Six (B) It is formed by the action of HCl on its precursor (C) Its optimum pH is 1.0–2.0 240. Light chains of immunoglobulins are of following types: (D) It hydrolyses the C-terminal and N-terminal peptide bonds of proteins (A) Alpha and kappa (B) Alpha and gamma (C) Lambda and delta(D) Kappa and lambda 234. Pancreatic juice contains the precursors of all of the following except 241 Immunoglobulins are classified on the basis of (A) Trypsin (B) Chymotrypsin (C) Carboxypeptidase (D) (A) Type of light chains (B) Type of heavy chains 235. The only correct statement about chymo- (C) Types of light and heavy chains trypsin is (D) Molecular weight (A) It is formed from trypsin (B) Carboxypeptidase converts trypsin into 242. The molecular weight of light chains is chymotrypsin (A) 10,000–15,000 (B) 20,000–25,000 (C) Its optimum pH is around 7 (C) 25,000–50,000 (D) 50,000–75,000 (D) It hydrolyses peptide bonds involving basic 243. The molecular weight of heavy chains is amino acids (A) 20,000–25,000 (B) 25,000–50,000 236. The portion of the antigen molecule which (C) 50,000–70,000 (D) 70,000–1,00,000 is recognized by antibody is known as 244. Secretory component is present in (A) Hapten (B) Epitope (A) IgA (B) IgG (C) Complement (D) Variable region (C) IgM (D) All of these 237. All the following statements about haptens are true except 245. The variable region of light chains is the (A) They have high molecular weights (A) N-terminal quarter (B) N-terminal half (C) C-terminal quarter (D) C-terminal half (B) They cannot elicit an immune response by PROTEINS AND PROTEIN METABOLISM 41

246. The variable region of light chain is the 256. The immunoglobulin having the longest (A) N-terminal quarter half-life is (B) N-terminal half (A) IgA (B) IgG (C) C-terminal quarter (C) IgM (D) IgE (D) C-terminal half 257. The half-life of IgG is 247. The variable region of light chains has (A) 2–3 days (B) 5–6 days (A) One hypervariable region (C) 8–10 days (D) 20–25 days (B) Two hypervariable regions (C) Three hypervariable regions 258. Recognition of antigen is the function of (D) Four hypervariable regions (A) Variable region of light chains 248. The variable region of heavy chains has (B) Variable regions of light and heavy chains (C) Constant region of heavy chains (A) One hypervariable region (D) Constant regions of light and heavy chains (B) Two hypervariable regions (C) Three hypervariable regions 259. The effector function of antibody is (D) Four hypervariable regions performed by 249. The most abundant immunoglobulin in (A) Variable region of light chains plasma is (B) Constant region of heavy chains (A) IgA (B) IgG (C) Variable regions of light and heavy chains (C) IgM (D) IgD (D) Constant regions of light and heavy chains 250. The largest immunoglobulin is 260. Complement system can be activated by (A) IgA (B) IgG binding of antigen to (C) IgM (D) IgD (A) IgA (B) IgD 251. The plasma concentration of IgA is (C) IgE (D) IgM (A) 1–5 mg/dl (B) 40–200 mg/dl 261. C1 component of classical complement (C) 60–500 mg/dl (D) 700–1,500 mg/dl pathway is made up of 252. An immunoglobulin found in exocrine (A) Complements 1q and 1r secretions is (B) Complements 1q and 1s (A) IgA (B) IgG (C) Complements 1r and 1s (C) IgM (D) IgE (D) Complements 1q, 1r and 1s 253. Allergic reactions are mediated by 262. The components of complement system (A) IgA (B) IgG are activated by (C) IgD (D) IgE (A) Microsomal hydroxylation 254. An immunoglobulin which can cross the (B) Phosphorylation placental barrier is (C) Glycosylation (A) IgA (B) IgM (D) Proteloysis (C) IgD (D) None of these 263. The component system forms a membrane 255. IgM possesses attack complex made up of (A) Two light chains and two heavy chains (A) Complements 1q, 1r and 1s (B) Four light chains and four heavy chains (B) Complements 1, 2, 3 and 4 (C) Six light chains and six heavy chains (C) Complements 5b, 6, 7 and 8 (D) Ten light chains and ten heavy chains (D) Factors B and D 42 MCQs IN BIOCHEMISTRY

264. Factors B and D are required in 272. Gamma heavy chains are present in (A) The classical pathway of complement fixation (A) IgA (B) IgG (B) The alternate complement pathway (C) IgM (D) IgD (C) Both (A) and (B) 273. Heavy chains in IgD are of following type: (D) None of these (A) Alpha (B) Gamma 265. The alternate complement pathway (C) Delta (D) Epsilon doesn’t involve (A) Antigen-antibody complex 274. On exposure to any antigen, the first antibody to be formed is of the following (B) Complement 3 class: (C) Factors B and D (D) Membrane attack unit (A) IgA (B) IgG (C) IgM (D) IgE 266. Antibody diversity arises from 275. Constant segment genes of heavy chains (A) Gene amplification are present in a cluster in which the first (B) Gene re-arrangement gene on side is (C) Alternative splicing (A) Alpha (B) Gamma (D) All of these (C) Delta (D) None of these 267. A light chain gene is constructed from the following segments: 276. Cell-mediated immunity is the function of (A) Variable and constant segments (A) B lymphocytes (B) T lymphocytes (B) Variable, joining and constant segments (C) Plasma cells (D) Basophils (C) Variable, diversity and constant segments 277. The most abundant T cells are (D) Variable, joining, diversity and constant (A) Cytotoxic T cells (B) Helper T cells segments (C) Suppressor T cells (D) Memory T cells 268. In metabolic point of view, amino acids are classified as 278. T cells can recognise (A) Glycogenic (A) Free antigens (B) Ketogenic (B) Antigens bound to cells (C) Glycogenic or Ketogenic (C) Antigens bound to antibodies (D) All of these (D) Antigens bound to MHC proteins 269. Diversity segments are present in 279. MHC proteins are unique to (A) Light chain genes (A) Each cell (B) Each organ (B) Heavy chain genes (C) Each individual (D) Each species (C) Light and heavy chain genes 280. MHC class I proteins are present on the (D) None of these surface of 270. Constant segments of heavy chains are (A) B cells only (B) T cells only of (C) Macrophages only(D) All cells (A) Five types (B) Six types 281. MHC class I proteins, in conjunction with (C) Seven types (D) Eight types antigens are recognised by 271. Gamma heavy chains are of (A) Cytotoxic T cells (B) Helper T cells (A) Two types (B) Three types (C) Suppressor T cells (D) Memory T cells (C) Four types (D) Five types PROTEINS AND PROTEIN METABOLISM 43

282. MHC class II proteins are present on the 290. Human immunodeficiency virus destroys surface of (A) Cytotoxic T cells (B) Helper T cells (A) All cells (C) B cells (D) Plasma cells (B) B lymphocytes only 291. In allergic diseases, the concentration of (C) Macrophages only the following is increased in plasma: (D) Macrophages and B lymphocytes (A) IgA (B) IgG 283. MHC Class II proteins, in conjunction with (C) IgD (D) IgE antigens, are recognised by 292. IgE has a tendency to attach to (A) Cytotoxic T cells (A) Basophils (B) Mast cells (B) Helper T cells (C) Both (A) and (B) (D) None of these (C) Suppressor T cells 293. Reaginic antibody is (D) Memory T cells (A) IgA (B) IgG 284. CD 8 is a transmembrane glycoprotein (C) IgD (D) IgE present in 294. Active immunity can be produced by (A) Cytotoxic T cells administration of (B) Helper T cells (A) Killed bacteria or viruses (C) Suppressor T cells (B) Live attenuated bacteria or viruses (D) Memory T cells (C) Toxoids 285. CD 4 is a transmembrane glycoprotein (D) All of these present in 295. Passive immunity can be produced by (A) Cytotoxic T cells (B) Helper T cells administration of (C) Suppressor T cells (D) Memory T cells (A) Pure antigens 286. CD 3 complex and p 56lck proteins are (B) Immunoglobulins present in (C) Toxoids (A) Cytotoxic T cells (B) Helper T cells (D) Killed bacteria or viruses (C) Both (A) and (B) (D) None of these 296. Helper T cells release all the following except 287. Cytotoxic T cells release (A) Interleukins (A) Perforins (B) Colony stimulating factors (B) Interleukins (C) Perforins (C) Colony stimulating factors (D) Tumour necrosis factor (D) Tumour necrosis factor 297. IgG cleaved by into 288. Helper T cells release (A) Two light and two heavy chains (A) Interleukins (B) Two Fab and one Fc fragments (B) Colony stimulating factors (C) Two pairs of one light and one heavy chain (C) Tumour necrosis factor each

(D) All of these (D) One Fab and two Fc fragments 289. MHC Class III proteins include 298. Bence-Jones protein is (A) Immunoglobulins (A) An immunoglobulin (B) Components of complement system (B) A dimer of heavy chains (C) T cells receptors (C) A dimer of light chains (D) CD4 and CD8 proteins (D) A dimer of one heavy and one light chains 44 MCQs IN BIOCHEMISTRY

299. Bence-Jones proteins possess all the 306. The recommended energy intake for an following properties except adult sedentary Indian man is (A) They are dimers of light chains (A) 1,900 kcal/day (B) 2,400 kcal/day (B) Their amino acids sequences are identical (C) 2,700 kcal/day (D) 3,000 kcal/day (C) Their N-terminal halves have variable amino 307. The recommended energy intake for an acid sequences adult sedentary Indian woman is (D) Their C-terminal halves have constant amino (A) 1,900 kcal/day (B) 2,200 kcal/day acid sequences (C) 2,400 kcal/day (D) 2,700 kcal/day 300. A Zwitterion is 308. During pregnancy, the following should (A) Positive ion (B) Negative ion be added to the calculated energy (C) Both (A) and (C) (D) None of these requirement: (A) 300 kcal/day (B) 500 kcal/day 301. After accounting for SDA, the net gain of (C) 700 kcal/day (D) 900 kcal/day energy from 25 gm of proteins is about (A) 70 kcal (B) 100 kcal 309. During first six months of lactation, the following increment in energy intake is (C) 130 kcal (D) 200 kcal recommended: 302. After accounting for SDA, the net gain of (A) 200 kcal/day (B) 300 kcal/day energy from 25 gm of carbohydrates is (C) 550 kcal/day (D) 1,000 kcal/day about 310. The proximate principles of diet are (A) 70 kcal (B) 95 kcal (A) Vitamins and minerals (C) 100 kcal (D) 105 kcal (B) Proteins 303. After accounting for SDA, the net gain of (C) Carbohydrates and fats energy from 100 gm of fat is about (D) Carbohydrates, fats and proteins (A) 600 kcal (B) 780 kcal 311. The limiting amino acid in wheat is (C) 900 kcal (D) 1020 kcal (A) Leucine (B) Lysine 304. If proteins, carbohydrates and fats are (C) Cysteine (D) Methionine consumed together: 312. The limiting amino acid in pulses is (A) The total SDA is the sum of individual SDAs (A) Leucine (B) Lysine of proteins, carbohydrates and fats (C) Tryptophan (D) Methionine (B) The total SDA is more than the sum of individual SDAs of proteins, carbohydrates 313. Maize is poor in and fats (A) Lysine (C) Carbohydrates and fats lower the SDA of (B) Methionine proteins (C) Tryptophan (D) Proteins raise the SDA of carbohydrates and (D) Lysine and tryptophan fats 314. The percentage of ingested protein/ 305. After calculating the energy requirement nitrogen absorbed into blood stream is of a person: known as (A) 10% kcal are subtracted on account of SDA (A) Net protein utilisation (B) 10% kcal are added on account of SDA (B) Protein efficiency ratio (C) 20% kcal are subtracted on account of SDA (C) Digestibility coefficient (D) 20% kcal are subtracted on account of SDA (D) Biological value of protein PROTEINS AND PROTEIN METABOLISM 45

315. Biological value of a protein is 323. Protein content of meat is about (A) The percentage of ingested protein/nitrogen (A) 10% (B) 13% absorbed into circulation (C) 16% (D) 20% (B) The percentage of ingested protein/nitrogen 324. Protein content of rice is about in the body (C) The percentage of ingested protein utilised (A) 7% (B) 12% for protein synthesis in the body (C) 15% (D) 20% (D) The gain in body weight (gm) per gm of 325. The calorific value of wheat is about protein ingested (A) 2.5 kcal/gm (B) 3.5 kcal/gm 316. Net protein utilisation depends upon (C) 4.5 kcal/gm (D) 5.5 kcal/gm (A) Protein efficiency ratio 326. For vegetarians, pulses are an important (B) Digestibility coefficient source of (C) Digestibility coefficient and protein efficiency (A) Carbohydrates (B) Proteins ratio (C) Fat (D) Iron (D) Digestibility coefficient and biological value 327. The amino acids present in pulses can 317. The gain in body weight (gm) per gm of supplement the limiting amino acids of protein ingested is known as (A) Cereals (B) Milk (A) Net protein utilisation (C) Fish (D) Nuts and beans (B) Protein efficiency ratio (C) Digestibility coefficient 328. Milk is a good source of (D) Biological value of protein (A) Proteins, calcium and iron 318. The following is considered as reference (B) Proteins, calcium and ascorbic acid standard for comparing the nutritional (C) Proteins, lactose and retinol quality of proteins: (D) Proteins, lactose and essential fatty acids (A) Milk proteins (B) Egg proteins 329. Milk is a good source of all of the following (C) Meat proteins (D) Fish proteins except 319. Biological value of egg proteins is about (A) Essential amino acids (A) 70 % (B) 80 % (B) Vitamin C (C) 86 % (D) 94 % (C) Galactose (D) Calcium and phosphorous 320. The following has the highest protein efficiency ratio: 330. Milk is poor in (A) Milk proteins (B) Egg proteins (A) Cholesterol (B) Retinol (C) Meat proteins (D) Fish proteins (C) Calcium (D) Iron 321. The following has the lowest protein 331. Egg is rich in all of the following except efficiency ratio: (A) Cholesterol (B) Saturated fatty acids (A) Maize proteins (B) Wheat proteins (C) Ascorbic acid (D) Calcium (C) Milk proteins (D) Rice proteins 332. A phosphoprotein present in egg is 322. Protein content of egg is about (A) Casein (B) Albumin (A) 10% (B) 13% (C) Ovoglobulin (D) Ovovitellin (C) 16% (D) 20% 46 MCQs IN BIOCHEMISTRY

333. Consumption of raw eggs can cause (C) Muscle wasting occurs in marasmus but not deficiency of kwashiorkor (A) Calcium (B) Lipoic acid (D) Subcutaneous fat disappears in marasmus (C) Biotin (D) Vitamin A but not in kwashiorkor 334. Egg is poor in 342. Energy reserves of an average well-fed adult man are about (A) Essential amino acids (A) 50,000 kcal (B) 100,000 kcal (B) Carbohydrates (C) 200,000 kcal (D) 300,000 kcal (C) Avidin (D) Biotin 343. During starvation, the first reserve nutrient to be depleted is 335. Cholesterol is present in all the following except (A) Glycogen (B) Proteins (C) Triglycerides (D) Cholesterol (A) Milk (B) Fish (C) Egg white (D) Egg yolk 344. Synthesis of the following enzymes is increased during starvation. 336. Meat is rich in all of the following except (A) Digestive enzymes (A) Iron (B) Fluorine (B) Gluconeogenic enzymes (C) Copper (D) Zinc (C) Urea cycle enzymes 337. Kwashiorkor occurs when the diet is (D) Glucokinase severely deficient in 345. In hypoparathyroidism (A) Iron (B) Calories (C) Proteins (D) Essential fatty acids (A) Plasma calcium and inorganic phosphorous are low 338. Clinical features of Kwashiorkor include (B) Plasma calcium and inorganic phosphorous all of the following except are high (A) Mental retardation (B) Muscle wasting (C) Plasma calcium is low and inorganic (C) Oedema (D) Anaemia phosphorous high (D) Plasma calcium is high and inorganic 339. Kwashiorkor usually occurs in phosphorous low (A) The post-weaning period (B) Pregnancy 346. The number of amino acid residues in calcitonin in (C) Lactation (D) Old age (A) 9 (B) 32 (C) 51 (D) 84 340. Marasmus occurs from deficient intake of 347. Calcitonin is synthesised in (A) Essential amino acids (B) Essential fatty acids (A) Parathyroid glands (C) Calories (B) Thyroid gland (D) Zinc (C) Pars intermedia of pituitary (D) Adrenal cortex 341. Marasmus differs from Kwashiorkor in the which of these following respect 348. Plasma calcium is lowered by (A) Mental retardation occurs in kwashiorkor but (A) Parathormone (B) Calcitonin not in marasmus (C) Aldosterone (D) Deoxycorticosterone (B) Growth is retarded in kwashiorkor but not in marasmus PROTEINS AND PROTEIN METABOLISM 47

349. ααα Cells of Islets of Langerhans secrete 357. Gastrin stimulates (A) Insulin (B) Glucagon (A) Gastric motility (B) Gastric secretion (C) Somatostatin (D) Cholecystokinin (C) Both (A) and (B) (D) None of these 350. A/G ratio is 358. Secretin is made up of (A) Strength of proteins (A) 17 amino acids (B) 27 amino acids (B) ratio of serum proteins (C) 37 amino acids (D) 47 amino acids (C) ratio of ceruloplasmin 359. Secretin causes all of the following except (D) None of these (A) Secretion of pancreatic juice 351. Insulin is made up of (B) Secretion of bile (A) A single polypeptide chain having 51 amino (C) Inhibition of gastric secretion acid residues (D) Stimulation of intestinal motility (B) A single polypeptide chain having 84 amino 360. All of the following statements about acid residues cholecystokinin pancreozymin are true (C) A-chain having 21 and B-chain having 30 except amino acid residues (D) A-chain having 30 and B-chain having 21 (A) It is secreted by mucosa of small intestine amino acid residues (B) It stimulates secretion of pancreatic juice rich in enzymes 352. The number of amino acid residues in pre- (C) It stimulates contraction of gall bladder proinsulin is (D) It inhibits gastric motility (A) 51 (B) 84 (C) 109 (D) 119 361. All of the following statements about pancreatic somatostain are true except 353. Pre-proinsulin contains a signal sequence (A) It is secreted by δ cells of islets of Langerhans having (B) It stimulates the secretion of gastrin (A) 9 amino acid residues (C) It inhibits the secretion of secretin (B) 19 amino acid residues (D) It inhibits the secretion of cholecystokinin- (C) 27 amino acid residues pancreozymin (D) 33 amino acid residues 362. Histidine is converted into histamine by 354. The number of intra-chain disulphide (A) Carboxylation (B) Decarboxylation bonds in pro-insulin: (C) Methylation (D) Hydroxylation (A) One (B) Two (C) Three (D) Four 363. Histamine is synthesised in (A) Brain (B) Mast cells 355. Pentagastrin is a (C) Basophils (D) All of these (A) Naturally occurring form of gastrin (B) Inactive metabolite of gastrin 364. Histamine causes all the following except (C) Active metabolite of gastrin (A) Stimulation of gastric secretion (D) Synthetic form of gastrin (B) Vasoconstriction (C) Pruritus 356. Secretion of gastrin is evoked by (D) Increase in capillary permeability (A) Entry of food into stomach

(B) Vagal stimulation 365. H2-receptors are blocked by (C) Lower aliphatic alcohols (A) Diphenhydramine (B) Mepayramine (D) All of these (C) Pyrilamine (D) Cimetidine 48 MCQs IN BIOCHEMISTRY

366. Serotonin is synthesised from 375. The most abundant protein in is (A) Serine (B) Phenylalanine (A) Collagen type I (C) Tyrosine (D) Tryptophan (B) Collagen type II 367. All the following statements about (C) Collagen type III serotonin are true except (D) Non-collagen proteins (A) It causes vasolidatation 376. The most abundant collagen in cartilages (B) It causes bronchoconstriction is (C) It is metabolized by (A) Type I (B) Type II (D) Its metabolite is 5-hydroxyindole acetic acid (C) Type III (D) Type IV 368. All the following statements about 377. Collagen and elastin have the following angiotensin are true except similarity:

(A) Its precursor is an α2-globulin (A) Both are triple helices (B) Its active form is an octapeptide (B) Both have hydroxyproline residues (C) It is a vasodilator (C) Both have hydrolysine residues (D) It increases the secretion of aldosterone (D) Both are glycoproteins 369. Methyl dopa decreases blood pressure by 378. Abnormal collagen structure is seen in all (A) Inhibiting the synthesis of catecholamines of the following except (B) Antagonising the action of aldosterone (A) I-cell disease (C) Stimulating the release of renin (B) (D) Inhibiting the breakdown of angiotensin (C) Menke’s disease 370. Binding of gamma-aminobutyric acid to (D) Ehlers-Danlos sydrome its receptors in brain increases the 379. I-cell disease results from absence of the permeability of cell membrane to following from lysosomal enzymes: – + (A) Cl (B) Na (A) Signal sequence + ++ (C) K (D) Ca (B) Mannose-6-phosphate 371. Binding of acetylcholine to its receptors (C) Sialic acid increases the permeability of cell (D) A serine residue membrane to 380. In I-cell disease, lysosomal enzymes (A) Ca++ (B) Na+ (C) K+ (D) Na+ and K+ (A) Are not synthesised (B) Are inactive 372. All of the following are glycoproteins (C) Lack signal sequence except (D) Cannot reach lysosomes (A) Collagen (B) Albumin (C) Transferrin (D) IgM 381. Renal glycosuria occurs due to (A) Increased filtration of glucose in glomeruli 373. Sialic acids are present in (B) Increased secretion of glucose by renal (A) Proteoglycans (B) Glycoproteins tubular cells (C) Both (A) and (B) (D) None of these (C) Decreased reabsorption of glucose by renal 374. hydrolyses tubular cells (D) Increased conversion of glycogen into glucose (A) Hyaluronic acid in tubular cells (B) Chondroitin sulphate (C) Heparin 382. Haematuria can occur in (D) Hyaluronic acid and chondroitin sulphate (A) Haemolytic anaemia PROTEINS AND PROTEIN METABOLISM 49

(B) Mismatched blood transfusion hours and, then, measure (C) Yellow fever (A) Serum urea (D) Stone in urinary tract (B) Serum 383. Haematuria can occur in all of the following (C) Urine output in one hour except (D) Specific gravity of urine (A) Acute glomerulonephritis 393. Among the following, the most sensitive (B) Cancer of urinary tract indicator of glomerular function is (C) Stone in urinary tract (A) Serum urea (D) Mismatched blood transfusion (B) Serum creatinine 384. Chyluria can be detected by addition of (C) Urea clearance the following to the urine: (D) Creatinine clearance (A) Sulphosalicylic acid (B) Nitric acid 394. All the following statements about inulin (C) Acetic anhydride (D) Chloroform are correct except 385. Normal range of serum urea is (A) It is completely non-toxic (A) 0.6–1.5 mg/dl (B) 9–11 mg/dl (B) It is completely filtered by glomeruli (C) 20–45 mg/dl (D) 60–100 mg/dl (C) It is not reabsorbed by tubular cells 386. Normal range of serum creatinine is (D) It is secreted by tubular cells (A) 0.6–1.5 mg/dl (B) 9–11 mg/dl 395. Non-protein nitrogenous substances in (C) 20–45 mg/dl (D) 60–100 mg/dl blood include all of the following except 387. Standard urea clearance is (A) Urea (B) Uric acid (C) Creatinine (D) Inositol (A) 54 ml/min (B) 75 ml/min (C) 110 ml/min (D) 130 ml/min 396. Non-protein nitrogenous substances in blood are raised in 388. Maximum urea clearance is (A) Starvation (A) 54 ml/min (B) 75 ml/min (B) Liver damage (C) 110 ml/min (D) 130 ml/min (C) Renal failure 389. Average creatinine clearance in an adult (D) All of these man is about 397. Creatinine clearance is deceased in (A) 54 ml/min (B) 75 ml/min (C) 110 ml/min (D) 130 ml/min (A) Acute tubular necrosis (B) Acute glomerulonephritis 390. Inulin clearance in an average adult man is about (C) Hypertension (D) Myopathies (A) 54 ml/min (B) 75 ml/min (C) 110 ml/min (D) 130 ml/min 398. Serum amylase is increased in Q391. Among the following, a test of tubular (A) Acute parotitis (B) Acute pancreatitis function is (C) Pancreatic cancer (D) All of these (A) Creatinine clearance 399. Maximum rise in serum amylase occurs in (B) Inulin clearance (A) Acute parotitis (C) PAH clearance (B) Acute pancreatitis (D) PSP excretion test (C) Chronic pancreatitis 392. A simple way to assess tubular function (D) Pancreatic cancer is to withhold food and water for 12 50 MCQs IN BIOCHEMISTRY

400. Serum lipase is increased in (B) Must be supplied in the diet because the human has an impaired ability to synthesize (A) Acute parotitis (B) Acute pancreatitis the carbon chain of the corresponding keto- (C) Infective hepatitis (D) Biliary obstruction acids 401. Which one of the following metabolites (C) Are identical in all species studied is not directly produced in the hexose (D) Are defined as those amino acids which monophosphate pathway? cannot be synthesized by the organism at a (A) Fructose-6-phosphate rate adequate to meet metabolic requirements (B) Dihydroxy acetone phosphate 408. Which among the following is an essential amino acid? (C) CO2 (D) Erythrose-4-phosphate (A) Cysteine (B) Leucine (C) Tyrosine (D) Aspartic acid 402. Which one of the following statements concerning glucose-6-phosphate dehydro- 409. Which among the following is a basic genase deficiency is correct? amino acid? (A) Young R.B.Cs, particularly reticulocytes, (A) Aspargine (B) Arginine contain the highest enzyme activity cells show (C) Proline (D) Alanine less enzyme activity 410. This amino acid cannot have optical (B) Glucose-6-P Dehydroglucose deficiency isomers: leads to disfuction of many tissues (C) G-6-p Dehydroglucose deficiency is due to a (A) Alanine (B) Histidine single deletion of a large sequence of DNA (C) Threonine (D) Glycine in the G-6-PD gene 411. The amino acid which contains a (D) G-6-PD deficiency is precipitated by ingestion guanidine group is of drugs such as aspirin (A) Histidine (B) Arginine 403. The phenomenon of inhibition of glycol- (C) Citrulline (D) Ornithine ysis by O is termed as 2 412. GABA(gama amino butyric acid) is (A) Red drop (B) Pasteur effect (A) Post-synaptic excitatory transmitter (C) Michaelis effect (D) Fischer’s effect (B) Post-synaptic inhibitor transmitter 404. Seratonin is derived in the body from the (C) activator of glia-cell function following amino acid: (D) inhibitor of glia-cell function (A) Phenylalanine (B) Histidine 413. Sulphur-containing amino acid is (C) Tryptophan (D) Serine (A) Glutathione (B) Chondroitin sulphate 405. Which amino acid is a lipotropic factor? (C) Homocysteine (D) Tryptophan (A) Lysine (B) Leucine 414. The useful reagent for detection of amino (C) Tryptophan (D) Methionine acids is 406. Which among the following is a nutrition- (A) Molisch reagent ally essential amino acid for man ? (B) Dichlorophenol Indophenol (A) Alanine (B) Glycine (C) Ninhydrin (C) Tyrosine (D) Tryptophan (D) Biuret 407. The essential amino acids 415. The amino acid which contains an indole group is (A) Must be supplied in the diet because the organism has lost the capacity to aminate the (A) Histidine (B) Arginine corresponding ketoacids (C) Glycine (D) Tryptophan PROTEINS AND PROTEIN METABOLISM 51

416. Sakaguchi reaction is answered by (A) Lysine (B) Glutamine (A) Lysine (C) Serine (D) Citrulline (B) Ornithine 425. An amino acid which contains a disulphide (C) Arginine bond is (D) Arginino succinic acid (A) Lysine (B) Methionine 417. The pH of an amino acid depends (C) Homocysteine (D) Cystine (A) Optical rotation (B) Dissociation constant 426. One of the following has a phenolic group: (C) Diffusion coefficient(D) Chain length (A) Histidine (B) Hydroxy lysine 418. When amino acids are treated with neutral (C) Seratonine (D) Hydroxy proline formaldehyde, the pH of the mixture 427. An amino acid not containing the usual— (A) Is not altered COOH group is (B) Increases (A) Alanine (B) Tryptophan (C) Decreases (C) Methionine (D) Taurine (D) First increases then decreases 428. Branched chain amino acids are 419. Which among the following has an imidazole group? (A) Cysteine and cystine (A) Histidine (B) Tryptophan (B) Tyrosine and Tryptophan (C) Proline (D) Hydroxy proline (C) Glycine and Serine (D) Valine, Leucine and Isoleucine 420. The amino acid exist as Zwitter ions when they are in 429. A Zwitter ion is one which has in aqueous solution: (A) solid state (B) acidic solution (C) alkaline solution (D) neutral solution (A) One positive charge and one negative charge (B) Two positive charges and one negative charge 421. Plasma proteins are isolated by (C) Two negative charges and one positive (A) Salting out (B) Electrophoresis charge (C) Flourimetry (D) Both (A) and (B) (D) No electrical charges at all 422. After digestion amino acids 430. The amino acid which gives yellow colour (A) Are absorbed into portal circulation with Ninhydrin in paper chromatography (B) Are absorbed into lymph is (C) Are excreted to the extent of 50% (A) Tyrosine (B) Proline (D) Converted into glucose in the intestine (C) Tryptophan (D) Alanine 423. Cysteine has the formula: 431. Hydroxylation of Proline and Lysine in a protein is effected by (A) CH3SH (A) Vitamin B1 (B) Vitamin B2 (B) H2N—CH2—COOH (C) Vitamin B6 (D) Vitamin C (C) HS—CH2—CH(NH2)—COOH

(D) S—CH2—CH(NH2)—COOH 432. Millon’s test is for identification of | (A) Tyrosine (B) Tryptophan

S—CH2—CH(NH2)—COOH (C) Proline (D) Arginine 424. The compound having the formula 433. Hopkins-Cole test is for identification of

H2N—CO—NH—CH2—CH2—CH2—CH— COOH is (A) Tyrosine (B) Tryptophan | (C) Arginine (D) Cysteine

NH2 52 MCQs IN BIOCHEMISTRY

434. Collagen is very rich in 445. The major end product of protein nitrogen (A) Glycine (B) Serine metabolism in man is (C) Aspartic acid (D) Glutamic acid (A) Glycine (B) Uric acid (C) Urea (D)NH 435. All amino acids are optically active except 3 (A) Glycine (B) Serine 446. An amino acid not involved in urea cycle (C) Threonine (D) Tryptophan is (A) Arginine (B) Histidine 436. Out of 200 different amino acids form in nature the number of amino acids present (C) Ornithine (D) Citrulline in protein: 447. NH3 is detoxified in brain chiefly as (A) 20 (B) 25 (A) Urea (B) Uric acid (C) 40 (D) 35 (C) Creatinine (D) Glutamine

437. Enzyme catalyzed hydrolysis of proteins 448. In humans, NH is detoxified in liver as produces amino acids of the form: 3 (A) Creatinine (B) Uric acid (A) D (B) L (C) Urea (D) Uronic acid (C) DL (D) All of these 449. The body protein after eighteen years 438. The ionizable groups of amino acids are at least. (A) Remains unchanged (A) 1 (B) 2 (B) Is decomposed only slightly at intervals of one month (C) 3 (D) 4 (C) Is in a constant state of flux 439. The neutral amino acid is (D) Is used only for energy requirement (A) Lysine (B) Proline 450. The only known physiological methylating (C) Leucine (D) Histidine agents in the animal organism are 440. The amino acid containing hydroxyl (A) Choline and betaine group: (B) Choline and δ-adenosyl methionine (A) Alanine (B) Isoleucine (C) Betaine and δ-adenyosyl methionine (C) Arginine (D) Threonine (D) Dimehtyl glycine and betaine 441. The sulphur containing amino acid: 451. In the synthesis of 1 molecule of urea in (A) Homoserine (B) Serine the Kreb’s Hanseleit cycle, the number of (C) Methionine (D) Valine ATPs required is 442. The basic amino acid: (A) 1 (B) 2 (A) Glycine (B) Leucine (C) 3 (D) 4 (C) Histidine (D) Proline 452. For biosynthesis of proteins 443. The amino acid which synthesizes many (A) Amino acids only are required hormones: (B) Amino acids and nucleic acids only are (A) Valine (B) Phenyl alanine required (C) Alanine (D) Histidine (C) Amino acid, nucleic acids and ATP only are required 444. Amino acids are insoluble in (D) Amino acids, nucleic acids, ATP, GTP, (A) Acetic acid (B) Chloroform enzymes and activators are required (C) Ethanol (D) Benzene PROTEINS AND PROTEIN METABOLISM 53

453. Transmethylation of guanido acetic acid 461. The first amino acid incorporated in a gives polypeptide in a ribosome of a human is (A) Creatine phosphate (A) N formyl methionine (B) Methionine (B) Creatinine (C) Phenyl alanine (D) Hydroxy lysine (C) Choline 462. The first amino acid incorporated in a (D) n-methyl nicotinamide polypeptide in a ribosome of a bacterium 454. The 2 energy rich compounds needed for is are (A) N formyl methionine (B) Methionine (A) ATP and GTP (B) ATP and UTP (C) Alamine (D) Glycine (C) ATP and CTP (D) ATP and TTP 463. The integrator between the TCA cycle and 455. The following ketoacid is involved in urea cycle is

fixing dietary NH3 into amino acid: (A) Fumarate (B) Malate (A) Pyruvate (B) Oxalo acetate (C) Pyruvate (D) Citrate (C) Oxalo succinate (D) α-keto glutarate 464. Bence jones proteinurial characterized by 456. The metabolite which sustains urea cycle (A) Non-heat coagulability is (B) Heat coagulability at 100°C (A) Ornithine (C) Heat coagulability at 45 to 60°C (B) Citrulline (D) Precipitation at 25°C (C) Carbamoyl phosphate 465. Bence Jones proteins may be excreted in (D) n-acetyl glutamate urine of patients suffering from 457. Tetra hydroglolate can be freed from N5 (A) Tuberculosis (B) Diabetes mellitus methyl tetrahydrofolate only by (C) Multiple myeloma (D) Hyperthyroidism (A) Nor epinephrine (B) Ethanol amine 466. Xanthuric acid is an abnormal metabolite (C) Nicotinamide (D) Vitamin B12 of 458. Neogenesis of methyl group is (A) Xanthine (B) Uric acid (A) The availability of methyl group form δ (C) Tyrosine (D) Tryptophan adenosyl methionine 467. Two nitrogen atoms of Urea in the urea (B) The availability of methyl group from betaine cycle come from (C) Interaction between N5 N10 methylene tetra (A) NH hydrofolate with a NAD+ dependent 3 reductase (B) One from NH3 and one from aspartate (C) One from NH3 and one from glutamate (D) Availability of methyl group from methyl B12 (D) One from NH3 and one from alanine 459. More creatinine is excreted by 468. Pyruvic acid can be obtained by transami- (A) Adult males (B) Adult females nation of alanine with (C) Children (D) Pregnant women (A) α- keto glutaric acid 460. A growing peptide in a ribosome can not (B) Acetoacetic acid be shifted to the adjacent ribosome (C) β−OH butyric acid because (D) Phosphoenol Pyruvic acid (A) It is firmly attached (B) It will get the amino acid cleaved 469. In the synthesis of 1 molecule of urea in the Kreb’s Henseleit cycle the number of (C) The gap between the ribosomes is too big for AMPs formed is a shift (D) The adjacent ribosomes have different (A) 1 (B) 2 composition (C) 3 (D) 4 54 MCQs IN BIOCHEMISTRY

470. Formation of melanin from tyrosine (B) H2N—Gly—Arg—Lys—Phe—COOH + Asp requires the action of (C) H2N—Arg—Lys—Phe—Asp—COOH + Gly (A) Dopa decarboxylation (D) H2N—Gly—Arg—Lys—COOH + H2N—Phe (B) Diamine oxidase —Asp—COOH (C) 478. Which of the following techniques is used (D) Tyrosinase to separate proteins based upon differ- 471. In one of the following the quality of the ences in their mass? protein synthesized is affected: (A) Isoelectric focusing (A) Diabetes mellitus (B) Gont (B) Dialysis (C) Multiple myeloma (D) Primaquine sensitivity (C) SDS-gel Electrophoresis (D) Western blotting 472. Citrulline is an intermediate of (A) TCA cycle (B) Urea cycle 479. The greatest buffering capacity at physiologic pH would be provided by a (C) Pentose cycle (D) Calvin cycle protein rich in which of the following 473. The semialdehydes are formed under the amino acids ? action of enzymes characterised as (A) Lysine (B) Histidine (A) Aldolases (C) Aspartic acid (D) Valine (B) Peptidyl lysyl 480. Which one of the amino acids could serve (C) as the best buffer at pH 7? (D) (A) Glutamic acid (B) Arginine 474. Which of the following statement about (C) Valine (D) Histidine the peptide bond is true? 481. Which one of the following statements (A) It is a carbon-carbon bond concerning glutamine is correct? (B) It has cis hydrogen and oxygen groups (A) Contains three tetratable groups (C) It is planar (B) Is classified as an acidic amino acid (D) It has rotational freedom (C) Contains an amide group 475. Isoenzymes for a given reaction (D) Migrates to the cathode during electro- phoresis at pH 7.0 (A) Have different spedificities (B) Have identical affinities for the same substrate 482. One of the given example is an amino acid: (C) Exhibit different electrophoretic motilities (D) Contain similar ratios of different polypeptide (A) Oh-Lysine (B) Protein chains (C) Leucine (D) Serine 476. The highest concentration of cystine can 483. The lone pair of electrons at one of the be found in ring nitrogens in the given amino acid makes a potential ligand, which is (A) Melanin (B) Chondroitin sulphate important in binding the iron atoms in (C) Myosin (D) Keratin hemoglobin: 477. One round of Edman degradation of the (A) Tryptophan (B) Threonine

peptide: H2N— Gly—Arg—Lys—Phe— (C) Histidine (D) Serine Asp— COOH would result in which of the 484. The amino acid which is not optically following structures or their phenyl isothi- active is ocyanate derivatives? (A) Alanine (B) Glycine (A) H2N—Gly—Arg—COOH + H2N—Lys— Phe— Asp—COOH (C) Glutamine (D) Lysine PROTEINS AND PROTEIN METABOLISM 55

485. Optically active compounds are capable of 494. In prehepatic jaundice, protein floccula- (A) Different reactions tion test is (B) Rotating plane of polarized light (A) Normal/weekly positive (C) Showing same chemical properties (B) Usually positive (D) None of these (C) Negative 486. The reference compound for absolute confi- (D) None of these guration of optically active compound is 495. Side chains of all amino acids contain (A) Alanine (B) Lactic acid aromatic rings except (C) Glyceraldehyde (D) Dihydroxy acetone (A) Pheynl alanine (B) Alanine 487. All the standard amino acids except the (C) Tyrosine (D) Tryptophan following have one chiral ‘c’ atom: 496. In Nitroprusside test, amino acid cystein (A) Threonine, Isoleucine produces (B) Isoleucine, Alanine (A) Blue colour complex (C) Threonine, Alanine (B) Red colour (D) Alanine, Glutamine (C) Yellow colour 488. The role of complement proteins: (D) Purple colour (A) Defense 497. Bonds that are formed between two (B) Helps immunity of the body cysteine residues is (C) Not predicatable (A) Disulphide (B) Peptide (D) None of these (C) Electrostatic (D) Hydrophobic 489. Optical isomers that are mirror images 498. The acid amide of Aspartic acid is and non superimposable are called (A) Glutamine (B) Arginine (A) Diastereomers (B) Euantiomers (C) dl isomers (D) Stereomers (C) Aspargine (D) Ornithine 490. Living cells have the unique ability to 499. It is the only amino acid having an synthesize only ______the form of ionizing ‘R’ group with a pK’ near 7 and optical isomer due to ______. is important in the active site of some enzymes: (A) ‘d’ form, stereospecific enzymes (B) ‘l’ form stereospecific enzymes (A) Arginine (B) Cystein (C) ‘d’ form, DNA (C) Cystine (D) Histidine (D) ‘L’ form, DNA 500. Hemoglobin has a high content of this 491. Isoelectric pH of an amino acid is that pH amino acid: at which it has a (A) Proline (B) Leucine (A) Positive charge (B) Negative charge (C) Arginine (D) Histicline (C) No net charge (D) All of these 501. A hexa peptide with 5 aspartic acid would 492. Albuminoids are similar to have a net charge at pH 7: (A) Albumin (B) Globulin (A) Neutral (B) Positive (C) Both A and B (D) None of these (C) Negative (D) Not predictable 493. Abnormal chain of amino acids in sickle 502. In the of cystinuria, the cells anaemia is patient excretes large quantities of (A) Alpha chain (B) Beta chain cystine in their urine and its low solubility (C) Gama chain (D) Delta chain causes crystalline cystine to precipitate as stones in kidneys. The remedy involves 56 MCQs IN BIOCHEMISTRY

ingesting Na HCO3. Reaction of this 508. The amino acid which has a pK near 4 and treatment is thus is negatively charged at pH 7 is (A) Alanine (B) Glutamic acid (A) NaHCO2 combines with cystine (C) Glutamine (D) Aspargine (B) NaHCO3 raises the pH above the isoelectric point of cystine 509. The side chain of which of the following (C) NaHCO3 prevents stone formation by amino acid contain sulphur atom? hydrolysis of cystine to cysteine (A) Methionine (B) Threonine (D) None of these (C) Leucine (D) Tryptophan 503. In the following reaction, Alanine acts as a 510. Which of the followings gives a positive test for Ninhydrin? H H (A) Reducing sugars (B) Triglycerides | | + + (C) Alpha aminoacids (D) Esterified Fats HN–33C –COO——→ H N–C –COOH | | 511. In glutathione (a tripeptide) is present CH 3 CH3 apart from Glutamic acid and cysteine:

(A) Acid (B) Base (A) Serine (B) Glycine (C) Leucine (D) Phenyl alanine (C) Zwitter ion (D) None of these 512. 2 -Amino 3-OH propanoic acid is 504. Amino acids excepting histidine are not good buffering agents in cell because (A) Glycine (B) Alanine (C) Valine (D) Serine (A) They exist as zwitter ions (B) Their pk and not in the physiological pH of a 513. All amino acids have one asymmetric cell carbon atom, except (C) Only Histidine has pk of its R group at 6.0 (A) Arginine (B) Aspargine unlike the others which have at a different pH (C) Histidine (D) Glycine (D) None of these 514. Number of amino acids present in the 505. At neutral pH Alanine has the following plant, animal and microbial proteins: structure: (A) 20 (B) 80 (C) 150 (D) 200 H H + (A) H2 N−− C COOH (B) HN3 −− C COO 515. Immunoglobulins are characterized by their CH CH 3 3 (A) Heavy chains H H + (B) Molecular weight (C) HN2 −− C COO (D) HN2 −− C COO (C) Light chains CH CH 3 3 (D) Electrophoretic behaviour 506. The amino acids in which the R groups have a net positive charge at pH 7.0 are 516. The bond in proteins that is not hydro- lysed under usual conditions of denatu- (A) Lysine, Arginine, Histidine ration: (B) Lysine, Aspargine (A) Hydrophobic bond (B) Hydrogen bond (C) Histidine, Aspargine (C) Disulphide bond (D) Peptide bonds (D) Glutamine, Arginine 517. If the amino group and a carboxylic group 507. Apolipoproteins are of the amino acid are attached to same carbon atom, the amino acid is called (A) AI (B) AI1 (C) C1 (D) All of these (A) Alpha (B) Beta (C) Gamma (D) Delta PROTEINS AND PROTEIN METABOLISM 57

518. Zymogen is 528. Physiologically active configuration of (A) An intracellular enzyme amino acids: (B) Serum enzyme (A) L (C) A complete extracellular enzyme (B) D (D) An inactivated enzyme (C) For some amino acids it is either of two (D) Neither L nor D 519. SGOT level in a adult is (A) 5–40 units/dl (B) 1–4 units/dl 529. Cystine is synthesized from (C) 5–15 units/dl (D) 50–100 units/dl (A) Cysteine (B) Methionine (C) Arginine (D) Leucine 520. Activity of ceruloplasmin shown in vitro: (A) Reductase (B) Hydrolase 530. The major constituent of the proteins of hair and keratin of skin: (C) (D) Oxidase (A) Arginine (B) Cysteine 521. Increased serum alanine during fasting is (C) Glycine (D) Arginine due to 531. NH is removed from brain mainly by (A) Breakdown of muscle proteins 3 (B) Decreased utilization of non essential amino (A) Creatinine formation acids (B) Uric acid production (C) Leakage of aminoacids to plasma (C) Urea formation (D) Impaired renal function (D) Glutamine formation

522. The following 4 amino acids are required 532. Mechanism by which NH3 is removed from for completion of urea cycle except the kidneys is (A) Aspartic acid (B) Arginine (A) Urea formation (C) Ornithine (D) Glycine (B) Uric acid formation 523. Number of amino acids present in the (C) Creatinine formation dietary proteins: (D) None of these (A) 22 (B) 23 533. Low density plasma proteins are rich in (C) 20 (D) 19 (A) Chylomicrons (B) Cholesterol 524. Urea synthesis takes place in (C) Triglycerides (D) Phospholipids (A) Blood (B) Liver 534. Transcortins are (C) Kidney (D) Heart (A) Mucoproteins (B) Glycoproteins 525. All followings are ketogenic aminoacids (C) Metalloproteins (D) Lipoproteins except 535. Proteins that carries Iron into different (A) Leucine (B) Isoleucine tissues is (C) Phenyl alanine (D) Glycine (A) Ceruloplasmin (B) Trans cortin 526. The amino acid containing an indole ring: (C) Mucoproteins (D) Glycoproteins (A) Tryptophan (B) Arginine 536. Naturally occurring amino acids have (C) Threonine (D) Phenylalanine (A) L-Configuration (B) D-Configuration 527. Histidine is converted to histamine (C) DL-Configuration (D) None of these through the process of 537. Abnormal chain of aminoacids in sickle (A) Transamination cell anemia is (B) Decarboxylation (A) β-chain (B) β-chain (C) Oxidative deamination (C) γ-chain (D) r-chain (D) Urea cycle 58 MCQs IN BIOCHEMISTRY

538. A dietary deficiency of tryptophan and 547. The amino acid which contains an indole nicotinate leads to group is (A) Beri Beri (B) Xerophthalmia (A) Histidine (B) Arginine (C) Anemia (D) Pellegra (C) Cystine (D) Tryptophan 539. Which one of the following is an essential 548. From two amino acids peptide bond amino acid? formation involves removal of one (A) Arginine (B) Tyrosine molecule of (C) Phenylalanine (D) Proline (A) Water (B) Ammonia (C) Carbondioxide (D) Carboxylic acid 540. One of the following amino acid is solely ketogenic: 549. Polymers of more than 100 amino acids are termed (A) Lysine (B) Alanine (C) Valine (D) Glutamate (A) Proteins (B) Polypeptides (C) Both (A) and (B) (D) None of these 541. Along with CO2, NH3 and ATP, the amino acid that is needed in urea cycle is 550. The example of : (A) Alanine (B) Isoleucine (A) Leucosin (B) Tuberin (C) Aspartate (D) Glycine (C) Oryzenin (D) Legunelin

542. Isoelectric pH of an amino acid is that pH 551. The example of scleroproteins: at which it has a (A) Glutamin (B) Giladin (A) Positive charge (B) Negative charge (C) Salmine (D) Elastin (C) No charge (D) None of these 552. The example of phosphoprotein: 543. Which of the following contributes (A) Mucin (B) Ovovitellin nitrogen atoms to both purine and (C) Ovomucoid (D) Tendomucoid pyrimidine rings? 553. The example of metalloproteins: (A) Aspartate (A) Siderophilin (B) OREES mucoid (B) Carbamoyl phosphate (C) Elastin (D) All of these (C) CO2 554. The example of chromoprotein: (D) Glutamine (A) Salmine (B) 544. Which amino acid is a lipotropic factor? (C) Zein (D) Gliadin (A) Lysine (B) Lecuine 555. Deamination is ______of amino group. (C) Tryptophan (D) Methionine (A) Removal (B) Addition 545. Which of the following protein is rich in (C) Supplementation (D) None of these cysteine? 556. Proteins produce polypeptides from (A) Elastine (B) Collagen proteins by (C) Fibrin (D) Keratin (A) Oxidizing (B) Reducing 546. Which amino acid is present at 6th position (C) Hydrolyzing (D) None of these of βββ-chain of Hbs instead of glutamate in HbA? 557. Proteins react with biuret reagent which is suggestive of 2 or more (A) Cysteine (B) Valine (A) Hydrogen bonds (B) Peptide bonds (C) Aspartate (D) Glutamate (C) Disulphide bonds (D) Hydrophobic bonds PROTEINS AND PROTEIN METABOLISM 59

558. The disulphide bond is not broken under 568. Foetal haemoglobin contains the usual conditions of (A) Two α and two γ chains (A) Filtration (B) Reduction (B) Two β and two γ chains (C) Oxidation (D) Denaturation (C) Both (A) and (B) 559. Insulin is oxidized to separate the protein (D) None of these molecule into its constituent polypeptide 569. When haemoglobin takes up oxygen chains without affecting the other part of the molecule by the use of there is a change in the structure due to the moving closer together of (A) Performic acid (B) Oxalic acid (A) β-chains (B) β-chains (C) Citric acid (D) Malic acid (C) γ-chains (D) α and γ chains 560. Each hydrogen bond is quite 570. The hydrogen bonds in the secondary and (A) Weak (B) Strong tertiary structure of proteins are directly (C) Both (A) and (B) (D) None of these attacked by 561. A coiled structure in which peptide bonds (A) Salts (B) Alkalies are folded in regular manner by (C) Detergents (D) All of these (A) Globular proteins (B) Fibrous proteins 571. The hydrogen bonds between peptide (C) Both (A) and (B) (D) None of these linkages are interfered by 562. In many proteins the hydrogen bonding (A) Guanidine (B) Uric acid produces a regular coiled arrangement called (C) Salicylic acid (D) Oxalic acid (A) α-helix (B) β-helix 572. The digestability of certain denatured (C) Both (A) and (B) (D) None of these proteins by proteolytic enzymes 563. Many globular proteins are stable in (A) Decreases (B) Increases solution although they lack in (C) Normal (D) None of these (A) Hydrogen bonds (B) Salt bonds 573. The antigenic antibody functions of (C) Non-polar bonds (D) Disulphide bonds proteins by denaturation are frequently 564. Each turn of ααα-helix contains the number (A) Not changed (B) Changed of amino acids (C) Both (A) and (B) (D) None of these

(A) 2.8 (B) 3.2 574. In case of severe denaturation of protein, (C) 3.4 (D) 3.6 there is 565. The distance travelled per turn of ααα-helix (A) Reversible denaturation in nm is (B) Moderate reversible denaturation (A) 0.34 (B) 0.44 (C) Irreversible denaturation (C) 0.54 (D) 0.64 (D) None of these

566. ααα-helix is disrupted by certain amino 575. When egg albumin is heated till it is acids like coagulated, the secondary and tertiary (A) Proline (B) Arginine structures of the proteins are completely lost (C) Histidine (D) Lysine resulting in a mixture of randomly arranged (A) Dipeptide chains (B) Tripeptide chains 567. ααα-helix is stabilized by (C) Polypeptide chains(D) All of these (A) Hydrogen bonds (B) Disulphide bonds (C) Salt bonds (D) Non-polar bonds 60 MCQs IN BIOCHEMISTRY

576. In glycoproteins the carbohydrate is in the 586. If one amino acid is fed excess, the form of disaccharide units, the number of absorption of another is units are (A) Slightly accelerated (A) 50–100 (B) 200–300 (B) Moderately accelerated (C) 400–500 (D) 600–700 (C) Highly accelerated 577. The milk protein in the stomach of the (D) Retarded infants is digested by 587. Under normal conditions, food proteins (A) Pepsin (B) Trypsin are generally readily digested upto the (C) Chymotrypsin (D) Rennin present 578. Achylia gastrica is said to be when absence (A) 67 to 73 (B) 74 to 81 of (C) 82 to 89 (D) 90 to 97 (A) Pepsin only (B) Both pepsin and HCl 588. By overheating the nutritional value of (C) HCl only (D) All of these cereal proteins is 579. The pH of gastric juice become low in (A) Increased (B) Decreased (A) Hemolytic anemia (B) Pernicious anemia (C) Unchanged (D) None of these (C) Both (A) and (B) (D) None of these 589. More than half of the protein of the liver 580. In small intestine trypsin hydrolyzes and intestinal mucosa are broken down peptide linkages containing and resynthesised in (A) Arginine (B) Histidine (A) 10 days (B) 12 days (C) Serine (D) Aspartate (C) 15 days (D) 18 days 581. Chymotrypsin in the small intestine hydrolyzes peptide linkages containing 590. The half-life of antibody protein is about (A) Alanine (B) Pheynl alanine (A) 4 weeks (B) 3 weeks (C) Valine (D) Methionine (C) 2 weeks (D) 1 week 582. Carboxy peptidase B in the small 591. Protein anabolism is stimulated by intestine hydrolyzes peptides containing (A) ACTH (B)Testosterone (A) Leucine (B) Isoleucine (C) Glucagon (D) Epinephrine (C) Arginine (D) Cysteine 592. The metabolism of protein is integrated 583. The transport of amino acids regulated by with that of carbohydrate and fat through active processes of different numbers: (A) Oxaloacetate (B) Citrate (A) 1 (B) 2 (C) Isocitrate (D) Malate (C) 3 (D) 4 593. The building up and breaking down of 584. The third active process for amino acids transport involves protoplasm are concerned with the metabolism of (A) Acidic amino acids (B) Basic amino acids (A) Carbohydrate (B) Lipid (C) Neutral amino acids (C) Protein (D) Minerals (D) Sulphur containing amino acids 594. The amino acids abstracted from the liver 585. The neutral amino acids for absorption are not utilized for repair or special need synthesis but are broken down to (A) Keto acids (B) Sulphur dioxide (A) TPP (B) B6 – PO4 (C) NAD+ (D) NADP+ (C) Water (D) Ammonia PROTEINS AND PROTEIN METABOLISM 61

595. The unwanted amino acids abstracted 603. The transaminase activity needs the from the tissues are either used up by the coenzyme: tissue or in the liver converted into (A) ATP (B) B6 – PO4 (A) Ammonia (B) Urea (C) FAD+ (D) NAD+ (C) Ammonium salts (D) Uric acid 604. Transamination is a 596. Amino acids provide the nitrogen for the (A) Irreversible process(B) Reversible process synthesis of (C) Both (A) and (B) (D) None of these (A) The bases of the phospholipids 605. Most amino acids are substrates for (B) Uric acid transamination except (C) Glycolipids (A) Alanine (B) Threonine (D) Chondroitin sulphates (C) Serine (D) Valine 597. The metabolism of all proteins ingested over and above the essential require- 606 Oxidative conversion of many amino ments is called acids to their corresponding -ketoacids occurs in mammalian: (A) Exogenous metabolism (A) Liver and kidney (B) Adipose tissue (B) Endogenous metabolism (C) Pancreas (D) Intestine (C) Both (A) and (B)

(D) None of these 607. The ααα-ketoacid is decarboxylated by H2O2 forming a carboxylic acid with one carbon 598. Sulphur containing amino acids after atom less in the absence of the enzyme: catabolism produces a substance which is excreted: (A) Catalase (B) Decarboxylase (C) Deaminase (D) Phosphatase (A) SO2 (B) HNO3

(C) H2SO4 (D) H3PO4 608. The activity of mammalian L-amino acid oxidase, an FMN – flavo protein, is quite 599. Ethereal sulphate is synthesized from the ______amino acid. (A) Slow (B) Rapid (C) Both (A) and (B) (D) None of these (A) Neutral (B) Acidic (C) Basic (D) Sulphur containing 609. From dietary protein as well as from the urea present in fluids secreted into the 600. The amino acids required for creatine gastrointestinal tract intestinal bacteria formation: produce (A) Glycine (B) Arginine (A) Carbondioxide (C) Methionine (D) All of these (B) Ammonia 601. In human and other ureotelic organisms, (C) Ammonium sulphate the end product of amino acid nitrogen (D) Creatine metabolism: 610. The symptom of ammonia intoxication (A) Bile acids (B) Ketone bodies includes (C) Urea (D) Barium sulphate (A) Blurring of vision (B) Constipation 602. The end product of amino acid nitrogen (C) Mental confusion (D) Diarrhoea metabolism in uricotelic organisms (reptiles and birds) is 611. Ammonia intoxication symptoms occur when brain ammonia levels are (A) Bilirubin (B) Urea (C) Uric acid (D) Biliverdin (A) Slightly diminished (B) Highly diminished (C) Increased (D) All of these 62 MCQs IN BIOCHEMISTRY

612. Ammonia production by the kidney is 621. In severe acidosis, the output of urea is depressed in (A) Decreased (B) Slightly increased (A) Acidosis (B) Alkalosis (C) Highly increased (D) Moderately increased (C) Both (A) and (B) (D) None of these 622. Uremia occurs in 613. Ammonia is excreted as ammonium salts (A) Cirrhosis of the liver(B) Nephritis during metabolic acidosis but the majority (C) Diabetes mellitus (D) Coronary thrombosis is excreted as (A) Phosphates (B) Creatine 623. Clinical symptom in urea cycle disorder is (C) Uric acid (D) Urea (A) Mental retardation (B) Drowsiness (C) Diarrhoea (D) Oedema 614. Synthesis of glutamine is accompanied by the hydrolysis of 624. The sparing action of methionine is (A) ATP (B) ADP (A) Tyrosine (B) Cystine (C) TPP (D) Creatin phosphate (C) Arginine (D) Tryptophan

615. In brain, the major metabolism for + 625. NH 4 aminates glutamate to form removal of ammonia is the formation of glutamine requiring ATP and (A) Glutamate (B) Aspartate (A) K+ (B) Na+ (C) Asparagine (D) Glutamine (C) Ca++ (D) Mg++ 616. Carbamoyl phosphate synthetase struc- 626. Glutathione is a ture is marked by change in the presence (A) Dipeptide (B) Tripeptide of (C) Polypeptide (D) None of these (A) N-Acetyl glutamate (B) N-Acetyl Aspartate 627. All following are conjugated proteins except (C) Neuraminic acid (D) Oxalate (A) Nucleoproteins (B) Proteoses (C) Metalloproteins (D) Flavoproteins 617. The biosynthesis of Urea occurs mainly in the Liver: 628. All ααα-amino acids have one asymmetric carbon atom except (A) Cytosol (B) Microsomes (A) Arginine (B) Glycine (C) Nucleus (C) Aspartic acid (D) Histidine (D) Mitochondria 629. Number of amino acids present in plants, animals and microbial proteins: 618. One mol. of Urea is synthesized at the expense of the ______mols. of ATP. (A) 20 (B) 80 (A) 2 (B) 3 (C) 150 (D) 200 (C) 4 (D) 5 630. Hydrated density of (HD) lipoproteins is 619. Urea biosynthesis occurs mainly in the (A) 0.94 gm/ml liver involving the number of amino acids: (B) 0.94-1.006 gm/ml (A) 3 (B) 4 (C) 1.006-1.063 gm/ml (C) 5 (D) 6 (D) 1.063-1.21 gm/l 620. The normal daily output of Urea through 631. The bond in proteins that is not broken urine in grams: under usual conditions of denaturation: (A) 10 to 20 (B) 15 to 25 (A) Hydrophobic bond (B) Hydrogen bond (C) 20 to 30 (D) 25 to 35 (C) Disulphide bond (D) Peptide bonds PROTEINS AND PROTEIN METABOLISM 63

632. Plasma proteins act as 642. Abnormal chain of amino acids in sickle (A) Buffers (B) Immunoglobulins cell anaemia is (C) Reserve proteins (D) All of these (A) Alpha chain (B) Beta chain (C) Delta chain (D) Gama chain 633. Group that reacts in the Biuret test: (A) Peptide (B) Amino group 643. Number of chains in globin part of normal Hb: (C) Carboxylic group (D) Aldehyde group (A) 1 (B) 2 634. In nitroprusside test, amino acid cysteine (C) 3 (D) 4 produces a: 644. The PH of albumin is (A) Red colour (B) Blue colour (A) 3.6 (B) 4.7 (C) Yellow colour (D) Purple colour (C) 5.0 (D) 6.1 635. Protein present in hemoglobin has the 645. Ninhydrin reaction gives a purple colour structure known as and evolves CO2 with (A) Primary (B) Secondary (A) Peptide bonds (B) Histamine (C) Tertiary (D) Quarternary (C) Ergothioneine (D) Aspargine 636. Isoelectric pH of an amino acid is that pH 646. Denaturation of proteins involves at which it has a breakdown of (A) Positive charge (B) Negative charge (A) Secondary structure(B) Tertiary structure (C) Nil net charge (D) None of these (C) Quarternary structure(D) All of these 637. Albuminoids are similar to 647. In denaturation of proteins, the bond (A) Albumin (B) Globulin which is not broken: (C) Both (A) and (B) (D) None of these (A) Disulphide bond (B) Peptide bond (C) Hydrogen bond (D) Ionic bond 638. Optical isomers of all aminoacids exist except 648. The purity of an isolated protein can be tested by employing various methods. (A) Glycine (B) Arginine (A) Solubility curve (C) Alanine (D) Hydroxy proline (B) Molecular weight 639. Proteins that constitute keratin, collagen (C) Ultra Centrifugation and elastin in body are (D) Immuno Ractivity (A) Protamines (B) Phosphol proteins (E) All of these (C) Scleroproteins (D) Metaproteins 649. More than one break in the line or in sat- 640. Systematic name of lysine is uration curve indicates the following quality of protein. (A) Amino acetic acid (A) Non homogenity (B) Purity (B) 2,6 diaminohexanoic acid (C) Homogeneity (D) None of these (C) Aminosuccinic acid (D) 2-Aminopropanoic acid 650. A sharp moving boundary is obtained between the pure solvent and solute 641. Side chains of all following amino acids containing layer in contain aromatic rings except (A) Chromatography (A) Phenyl alanine (B) Alanine (B) Immuno Reactivity (C) Tyrosine (D) Tryptophan (C) Ultra Centrifugation (D) Solubility curve 64 MCQs IN BIOCHEMISTRY

651. The antibodies raised against a pure 658. The sorting out of molecules according to protein will show only one sharp spike on size and shape may be adapted to protein this technique: purification in this technique: (A) Solubility curve (A) Adsorption chromatography (B) Solvent precipitation (B) Gel filtration chromatography (C) Molecular weight determination (C) Paper chromatography (D) Immuno electrophoresis (D) None of these 652. This technique takes the advantage of the 659. Frequently employed materials for the fact that each protein has different pH at adsorption chromatography of proteins which it is electrically neutral i.e., its include isoelectric pH: (A) High capacity supporting gel (A) Isoelectric focussing (B) Starch blocks (B) Immunoel Ectro Phoresis (C) Calcium phosphate gel alumina gel and hydroxy apatite (C) Chromatography (D) All of these (D) HPLC 660. The solubility of most proteins is lowered 653. The following technique makes use of the at high salt concentrations is called as difference in net charges of proteins at a given pH: (A) Salting in process (B) Salting out process (C) Isoelectric focussing(D) None of these (A) Thin layer chromatography (B) Ion exchange chromatography 661. Phenylalanine, ornithine and methionine are involved in the biogenesis of (C) High performance liquid chromatography (D) Paper chromatography (A) Lysergic acid (B) Reserpine (C) L-Hyoscyamine (D) Papaverine 654. The ratio of the distance moved by a compound to the distance moved by the 662. All the following diuretics inhibit the solvent frent is known as its carbonic anhydrase except (A) PI value (B) Linking number (A) Acetazolamide (B) Bumetanide (C) Rf value (D) Gold number (C) Furosemide (D) Ethacrynic acid 655. The movement of charged particles 663. Protein is a polymer of towards one of the electrodes under the (A) Sugars (B) Phenols influence of electrical current is (C) Amino acids (D) Carboxylic acids (A) Gel filtration 664. All the following amino acids are optically (B) Molecular sieving active except (C) Gas liquid chromatography (A) Tryptophane (B) Phenylalanine (D) Electrophoresis (C) Valine (D) Glycine 656. An anion exchange resin linked to 665. Proteinous substances which catalyze cellulose backbone is biochemical reactions are known as (A) DEAE cellulose (B) CM cellulose (A) Activators (B) Catalysts (C) Sephadex (D) None of these (C) Enzymes (D) Hormones 657. A cation exchange resin linked to cellulose 666. Insulin is a protein which controls backbone is (A) Blood clotting (B) Metabolic pathway (A) CM-cellulose (B) DEAE cellulose (C) Digestion (D) Kreb’s cycle (C) Starch (D) Biogel PROTEINS AND PROTEIN METABOLISM 65

667. Proteins which are responsible for defence 677. Protein deficiency disease is known as mechanism are called (A) Cushing’s disease (A) Antimetabolites (B) Antibodies (B) Fabry’s disease (C) Antimycins (D) Apoproteins (C) Parkinson’s disease 668. When the net charge on an amino acid is (D) Kwashiorkor and marasmus zero, the pH is maintained as? 678. A vegetable source of protein is (A) 4.5 (B) 11.2 (A) Egg plant (C) 7.0 (D) 9.1 (B) Soyabean 669. Isoelectric point of amino acids is used for (C) Tree of the Heaven (A) Crystallisation (B) Precipitation (D) Devil’s dung (C) Solubility (D) Reactivity 679. Oxaloacetate is converted to aspartic acid 670. Xanthoproteic test is positive in proteins by containing (A) Reductase (B) Oxidase (A) Sulphur amino acids (C) Transminase (D) Catalase (B) α-Amino acids 680. Deficiency of biotin results in decrease in (C) Aromatic amino acids (A) (D) Aliphatic amino acids (B) Lipid synthesis 671. All ααα-amino acids give positive (C) Kidney (A) Million’s test (B) Biurete test (D) Fatty acid synthesis (C) Xanthproteic test (D) Ninhydrine test 681. The precursor of bile salts, sex hormones 672. N-terminal amino acids of a polypeptide and vitamin D is are estimated by (A) Diosgenin (B) Cholesterol (A) Edmann reaction (B) Sanger’s reagent (C) Campesterol (D) Ergosterol (C) Formaldehyde test (D) Ninhydrine reaction 682 Unsaturated fatty acids is known as 673. Million’s test is positive for (A) Non-essential fatty acids (A) Phenylalanine (B) Glycine (B) Essential fatty acids (C) Tyrosine (D) Proline (C) Cerebrosides (D) Phospholipids 674. Indole group of tryptophan responses positively to 683 Biuret test is specific for (A) Glyoxylic acid (B) Schiff’s reagent (A) Two peptide linkage (C) Biuret test (D) Resorcinol test (B) Phenolic group 675. Guanidine group of argentine gives (C) Imidazole ring positive test with (D) None of these (A) Lead acetate 684. Most of calcium is present in , but 2% (B) Sakaguchi reagent present in soft tissue and the blood is (C) Tricholoroacetic acid called (D) Molisch’s reagent (A) Calcinated blood (B) Solidified blood 676. Thiol group of cysteine gives red colour (C) Physiological blood(D) Colloidal blood with 685. Calcium present with protein is known as (A) Sodium acetate free while in salt form is called as (B) Lead acetate (A) Bound (B) Precipitated (C) Sodium nitroprusside (C) Solid (D) Polymorphs (D) Barfoed’s reagent 66 MCQs IN BIOCHEMISTRY

686. The following ions help in enzymatic 695. Platelets contain an enzyme which has transfer of phosphate from ATP to pyruvic important role in clotting in blood. This acid: enzyme is known as (A) Sodium (B) Calcium (A) (B) Transaminase (C) Magnesium (D) Potassium (C) Decarboxylase (D) Thrombokinase 687. International enzyme commission classi- 696. Treatment of pentoses with a concentrated fies enzymes into mineral acid yields a cyclic aldehyde (A) Three classes (B) Six classes known as (C) Four classess (D) Ten classes (A) Pentaldehyde (B) Cyclopental 688. Michaelis – Menten equation is used to (C) Hexaldehyde (D) Furfural explain the effect of substrate concentra- tion on 697. Isoelectric pH is that pH at which protein is electrically: (A) Carbohydrate (B) Enzyme (C) Lipid (D) Protein (A) Neutral (B) Anionic (C) Cationic (D) None of these 689. The pH at which an enzyme has maximum activity is known as 698. About 6.25 g of haemoglobin is produced (A) Isoelectric pH (B) Optimum pH and destroyed in the body each day and the total amount of haemoglobin in a normal (C) Low pH (D) High pH healthy 70 kg weighing male adult is 690. Degradation of proteins to amino acids, (A) 250 g (B) 150 g glucose from carbohydrates and fatty acids from lipids is known as (C) 100 g (D) 70 g (A) Anabolism (B) Metabolism 699. Pancreatic juice contains all of the (C) Catabolism (D) Cretinism following except 691. During glycolysis of glucose the energy (A) Trypsinogen (B) Lipase liberated in the absence of oxygen is (C) Cholecystokinin (D) Chymnotrypsinogen known as 700. The milk protein in the stomach in an adult (A) Oxygenesis is digested by (B) Glyconeogenesis (A) Pepsin (B) Rennin (C) Glycogenolysis (C) HCl (D) Chymotrypsinogen (D) Anaerobic fermentation 701. Carboxypeptidase, an enzyme of 692. Deficiency of urea cycle enzymes results pancreatic juice, contains into accumulation of citrulline argininosuc- cinate arginine in the liver resulting in in- (A) Mn (B) Zinc creasing concentration of …….. in the blood. (C) Magnesium (D) Manganese (A) Calcium (B) Sodium 702. The zymogen from trypsinogen of (C) Ammonia (D) Lipid pancreatic juice is converted to active 693. Accumulation of trytophan in blood is trypsin by known as (A) Peisin (B) Enterocrinin (A) Pompe’s disease (B) Wilson’s disease (C) Enterokinase (D) Rennin (C) Wolman’s disease (D) Hartnup’s disease 703. Inactive zymogens are precursors of all 694. Lymphocytes are responsible for the for- the following gastrointestinal enzymes mation of except (A) Serum (B) Plasma (A) Carboxypeptidase (B) Pepsin (C) Antibody (D) Calcium (C) Amino peptidase (D) Chymotrypsin PROTEINS AND PROTEIN METABOLISM 67

704. Rennin acts on casein of milk in infants in 713. The milk protein in the stomach of the presence of infants is digested by (A) Mg++ (B) Zn++ (A) Pepsin (B) Trypsin (C) Co++ (D) Ca++ (C) Chymotrypsin (D) Rennin

705. All the following are true about phenyl- 714. Protein anabolism is stimulated by ketonuria except (A) ACTH (B)Testosterone (A) Deficiency of phenylalanine hydroxylase (C) Glucagon (D) Epinephrine (B) Mental retardation 715. The number of helices present in a collagen (C) Increased urinary excretion of p-hydroxy- molecule is phenyl pyruvic acid (D) Decrease serotonin formation (A) 1 (B) 2 (C) 3 (D) 4 706. Which of the amino acid produces a vasodilator on decarboxylation? 716. Which bond is present in the primary (A) Glutamin acid (B) Histidine structure of protein? (C) Ornithine (D) Cysteine (A) Ester (B) Hydrogen (C) Ionic bond (D) Peptide 707. Neutral amino acid is (A) Leucine (B) Lysine 717. Sakaguchi reaction is specific for (C) Aspartic acid (D) Histidine (A) Guanidine group (B) Phenolic group (C) Carboxylic group (D) None of these 708. The amino acid containing hydroxy group: (A) Glycine (B) Isoleucine 718. With the exception of glycine all amino (C) Arginine (D) Thereonine acids found in protein are (A) Isocitrate dehydrogenase 709. The amino acid which synthesizes many hormornes: (B) Fumarase (C) Succinate thiokinase (A) Valine (B) Phenylalanine (D) ATPase (C) Alanine (D) Histidine 719 In the αα-helix and ββ- 710. Insulin degradation of bond ααα βββ pleated sheets are example of formation is effected by (A) Pyruvate dehydrogenase (A) Primary structure (B) Secondary structure (B) Xylitol reductase (C) Tertiary structure (D) Quaternary structure (C) Gutathione reductase 720. An essential amino acid in man is (D) (A) Proline (B) Threonine 711. A protein reacts with biuret reagent which (C) Asparagine (D) Tyrosine indicates 2 or more 721. An amino acid that does not form an ααα- (A) Blood clotting (B) Peptide bond helix is (C) Disulphide bonds (D) Hydrophobic bonds (A) Asparagine (B) Tyrosine 712. In many proteins the hydrogen bonding (C) Tryptophan (D) Proline produces a regular coiled arrangement 722. The protein present in hair is which is called as (A) Elastin (B) Prolamine (A) β-Helix (B) α-Helix (C) Both (A) and (B) (D) Spiral (C) Keratin (D) Gliadin 68 MCQs IN BIOCHEMISTRY

723. Plasma protein can be separated by (A) TPP (B) Mg++ (C) Biotin (D) CoA-SH (A) Salting out with (NH4)2SO4 (B) Ultracentrifugation 727. A polymeric unit of starch which has a (C) Immuno electrophoresis branched structure is (D) All of these (A) Glucose (B) Amylopectin 724. RNA does not contain (C) Isomaltose (D) Amylose (A) Uracil 728 The repeating unit in hyaluronic acid is (B) Adenine (A) Glucuronic acid and Galactosamine (C) Hydroxy methyl cytosine (B) Glucuronic acid are glucosamine (D) Phosphate (C) Glucuronic acid and N-acetyl glucosamine 725. In mammalian cells, ribosomal RNA is (D) Glucuronic acid and N-acetyl galactosamine produced mainly in the 729 The repeating disaccharide unit in (A) Nucleus celluslose is (B) Nucleolus (A) Sucrose (B) Maltose (C) Ribosome (C) Dextrose (D) Cellobiose (D) Golgi apparatus 726. Which co-enzyme is not involved in oxidative decarboxylation of pyruvic acid? PROTEINS AND PROTEIN METABOLISM 69

ANSWERS 1. A 2. A 3. A 4. A 5. A 6. A 7. A 8. A 9. A 10. D 11. B 12. A 13. A 14. C 15. C 16. B 17. B 18. C 19. B 20. C 21. B 22. A 23. B 24. D 25. A 26. C 27. B 28. B 29. A 30. A 31. C 32. B 33. D 34. B 35. C 36. A 37. B 38. C 39. C 40. B 41. B 42. A 43. B 44. C 45. C 46. A 47. A 48. B 49. D 50. A 51. A 52. A 53. D 54. A 55. B 56. A 57. C 58. B 59. C 60. A 61. B 62. A 63. D 64. C 65. D 66. C 67. A 68. D 69. A 70. A 71. C 72. B 73. A 74. B 75. A 76. A 77. D 78. D 79. A 80. A 81. C 82. A 83. C 84. D 85. C 86. B 87. B 88. A 89. A 90. A 91. A 92. B 93. C 94. D 95. A 96. A 97. A 98. D 99. A 100. A 101. D 102. D 103. D 104. D 105. A 106. A 107. A 108. C 109. D 110. A 111. A 112. A 113. A 114. B 115. D 116. C 117. A 118. A 119. D 120. C 121. B 122. B 123. A 124. A 125. A 126. A 127. B 128. C 129. A 130. A 131. B 132. C 133. A 134. A 135. A 136. A 137. C 138. A 139. A 140. D 141. C 142. A 143. C 144. B 145. A 146. B 147. B 148. B 149. D 150. A 151. A 152. B 153. C 154. C 155. B 156. C 157. D 158. D 159. C 160. C 161. B 162. D 163. A 164. D 165. C 166. B 167. D 168. D 169. C 170. C 171. D 172. B 173. A 174. D 175. D 176. C 177. B 178. B 179. A 180. A 181. C 182. C 183. B 184. C 185. B 186. C 187. D 188. A 189. B 190. D 191. C 192. C 193. B 194. C 195. D 196. B 197. D 198. C 199. B 200. B 201. C 202. D 203. C 204. C 205. D 206. C 207. D 208. B 209. A 210. D 211. C 212. A 213. C 214. A 215. C 216. D 217. B 218. D 219. B 220. B 221. C 222. D 223. C 224. C 225. C 226. D 227. C 228. D 229. C 230. A 231. C 232. D 233. D 234. D 235. C 236. B 237. A 238. D 239. B 240. D 241. B 242. B 243. C 244. A 245. B 246. A 247. C 248. D 249. B 250. C 251. C 252. A 70 MCQs IN BIOCHEMISTRY

253. D 254. D 255. D 256. B 257. D 258. B 259. D 260. D 261. D 262. D 263. D 264. B 265. A 266. B 267. B 268. D 269. B 270. D 271. C 272. B 273. C 274. C 275. D 276. B 277. B 278. D 279. C 280. D 281. A 282. D 283. B 284. C 285. A 286. D 287. B 288. B 289. D 290. B 291. D 292. C 293. D 294. D 295. B 296. C 297. B 298. C 299. B 300. C 301. A 302. B 303. B 304. C 305. B 306. B 307. A 308. A 309. C 310. D 311. B 312. D 313. D 314. C 315. B 316. D 317. B 318. B 319. D 320. B 321. A 322. B 323. D 324. A 325. B 326. B 327. A 328. C 329. B 330. D 331. C 332. D 333. C 334. B 335. C 336. B 337. C 338. A 339. A 340. C 341. D 342. B 343. A 344. B 345. C 346. B 347. B 348.B 349. B 350. B 351. C 352. C 353. B 354. C 355. D 356. D 357. C 358. B 359. D 360. D 361. B 362. B 363. D 364. B 365. D 366. D 367. A 368. C 369. A 370. A 371. D 372. B 373. B 374. D 375. A 376. B 377. A 378. B 379. D 380. B 381. D 382. D 383. D 384. D 385. C 386. A 387. A 388. B 389. C 390. D 391. D 392. D 393. D 394. D 395. C 396. B 397. D 398. B 399. B 400. A 401. B 402. A 403. B 404. C 405. D 406. D 407. B 408. B 409. B 410. D 411. B 412. B 413. C 414. C 415. D 416. C 417. B 418. C 419. A 420. D 421. D 422. A 423. C 424. D 425. D 426. C 427. D 428. D 429. A 430. B 431. D 432. A 433. B 434. A 435. A 436. A 437. B 438. B 439. C 440. D 441. C 442. C 443. B 444. D 445. C 446. B 447. D 448. C 449. C 450. C 451. C 452. D 453. A 454. A 455. B 456. C 457. D 458. C 459. A 460. C 461. B 462. A 463. A 464. C 465. C 466. D 467. B 468. A 469. A 470. D 471. C 472. B 473. A 474. B 475. B 476. D 477. C 478. C 479. B 480. D 481. C 482. B 483. C 484. B 485. B 486. C 487. C 488. D 489. B 490. B 491. C 492. C 493. B 494. A 495. B 496. B 497. A 498. C 499. D 500. D 501. C 502. C 503. C 504. C 505. B 506. A 507. D 508. B 509. A 510. C PROTEINS AND PROTEIN METABOLISM 71

511. B 512. D 513. D 514. A 515. A 516. C 517. A 518. D 519. A 520. D 521. A 522. D 523. C 524. B 525. D 526. A 527. B 528. A 529. A 530. B 531. D 532. D 533. B 534. A 535. B 536. A 537. B 538. D 539. C 540. A 541. C 542. C 543. A 544. D 545. D 546. B 547. D 548. A 549. A 550. B 551. D 552. B 553. A 554. B 555. A 556. C 557. B 558. D 559. A 560. A 561. A 562. A 563. D 564. D 565. C 566. A 567. A 568. A 569. A 570. B 571. A 572. A 573. B 574. C 575. C 576. D 577. D 578. B 579. B 580. A 581. B 582. C 583. C 584. C 585. B 586. D 587. D 588. B 589. A 590. C 591. B 592. A 593. C 594. D 595. B 596. A 597. A 598. C 599. D 600. D 601. C 602. C 603. B 604. B 605. B 606. A 607. A 608. A 609. B 610. A 611. C 612. B 613. D 614. A 615. D 616. A 617. D 618. B 619. D 620. C 621. A 622. B 623. A 624. B 625. D 626. B 627. B 628. B 629. D 630. B 631. D 632. D 633. A 634. A 635. D 636. C 637. A 638. A 639. C 640. B 641. B 642. B 643. D 644. B 645. D 646. D 647. B 648. C 649. A 650.C 651. D 652. A 653. B 654. C 655. D 656. A 657. A 658. B 659. C 660. B 661. A 662. D 663. C 664. D 665. C 666. B 667. B 668. C 669. B 670. C 671. D 672. A 673. C 674. A 675. B 676. C 677. D 678. B 679. C 680. D 681. B 682. B 683. A 684. C 685. A 686. D 687. B 688. B 689. B 690. C 691. D 692. C 693. D 694. C 695. D 696. D 697. A 698. D 699. C 700. A 701. B 702. C 703. C 704. D 705. C 706. B 707. A 708. D 709. B 710. C 711. B 712. B 713. D 714. B 715. C 716. D 717. A 718. B 719. B 720. B 721. D 722. C 723. D 724. C 725. B 726. C 727. B 728. C 729. D 72 MCQs IN BIOCHEMISTRY

EXPLANATIONS FOR THE ANSWERS 12. A Albumin (mol. Wt. 69,000) is the major or an increase in globulins (chronic infections). constituent of plasma proteins with a 421. D By salting out technique (using ammonium concentration 3.5–5.0 g/dl. It is exclusively sulfate or sodium sulfate), the plasma proteins synthesized by the liver. Plasma albumin can be separated into 3 groups – albumin, performs osmotic, transport and nutritive globulins and fibrinogen. Electrophoresis is the function, besides the buffering action. most commonly employed analytical technique 67. A Ceruloplasmin is a blue coloured, copper for the separation of plasma (serum) proteins. containing α2–globulin. Its normal plasma Paper or agar gel electrophoresis with veronal concentration is around 30 mg/dl and it is buffer (pH 8.6) separates plasma proteins into

decreased in Wilson’s disease. 5 distinct bands namely albumin, α1 - α2, β-and γ-globulins. 103. D Defects in clotting factors cause abnormalities in blood clotting. Hemophilia A (defect- 488. D Complement system is composed of about 20 antihemophilic factor i.e., VII), hemophilia B or plasma proteins that complement the functions Christmas disease (defect-Christmas factor, i.e., of antibodies in defending the body from IX) are the major abnormalities known. invading antigens. The complement system helps the body immunity by promoting phagocytosis, 151. A Lysine, arginine, histidine. These are dibasic formation of antigen-antibody complexes and monocarboxylic acids. inflammatory reaction. 212. A The amino acids which are never found in 507. D Apolipoproteins or apoproteins are the protein structure are collectively referred to as non-protein amino acids. However, the non- (structural) protein components of lipoproteins protein amino acids perform several biological and are closely involved in the metabolism of the later, e.g., AI, AIII, B , C , CII functions. e.g., ornithine, citrulline, thyroxine. 100 1 268. D Amino acids are divided into 3 groups based 555. A The removal of amino group from the amino on their metabolic fats. acids as ammonia is deamination. It may be oxidative or non-oxidative in nature. The NH3 (a) Glycogenic: These amino acids can serve as so liberated is used for synthesis or urea. precursors for the synthesis of glucose (or glycogen) e.g., alanine, aspartate, glycine. 600. D The three amino acids glycine, arginine and methionine are required for creatine formation. (b) Ketogenic: Fat can be synthesized from these Glycine combines amino acids e.g., leucine, lysine. 683. A Biuret test is answered by compounds containing (c) Glycogenic or ketogenic: The amino acids that two or more CO–NH groups i.e., peptide can form glucose as well as fat e.g., isoleucine, bonds. All protein and peptides possessing at phenylalanine, lysine. least two peptide linkages i.e., tripeptide (with 300. C Zwitterion (dipolar ion) is a hybrid molecule 3 amino acids) give positive biuret test. The containing positive and negative ionic groups. principle of biuret test is conveniently used to Each amino acid has a characteristic pH (e.g., detect the presence of proteins in biological leucine pH 6.0), at which it exists as zwitterions. fluids. The mechanism of biuret test is not clearly known. It is believed that the colour is due to 350. B Albumin/Globulin (A/G) ratio expresses their relation in the serum concentration. The normal the formation of a copper co-ordianated A/G ratio is 1.2 to 1.5:1, taking the complex. concentration of albumin and globulins 717. A Arginine, containing guanidine group, reacts respectively in the range of 3.5-5.0 g/dl and with α-naphthol and alkaline hypobromite to 2.5–3.5 g/dl. The A/G ratio is lowered either form a red colour complex. due to a decrease in albumin 9liver disease) FATS AND FATTY ACID METABOLISM 73

CHAPTER 4

FFFAAATSTSTS ANDANDAND FFFAAATTYTTYTTY AAACIDCIDCID MMMETETETABOLISMABOLISMABOLISM

1. An example of a hydroxy fatty acid is 8. In humans, a dietary essential fatty acid (A) Ricinoleic acid (B) Crotonic acid is (C) Butyric acid (D) Oleic acid (A) Palmitic acid (B) Stearic acid (C) Oleic acid (D) Linoleic acid 2. An example of a saturated fatty acid is (A) Palmitic acid (B) Oleic acid 9. A lipid containing alcoholic amine residue is (C) Linoleic acid (D) Erucic acid (A) Phosphatidic acid (B) Ganglioside 3. If the fatty acid is esterified with an (C) Glucocerebroside (D) Sphingomyelin alcohol of high molecular weight instead of glycerol, the resulting compound is 10. Cephalin consists of (A) Lipositol (B) Plasmalogen (A) Glycerol, fatty acids, phosphoric acid and (C) Wax (D) Cephalin choline 4. A fatty acid which is not synthesized in (B) Glycerol, fatty acids, phosphoric acid and the body and has to be supplied in the ethanolamine diet is (C) Glycerol, fatty acids, phosphoric acid and inositol (A) Palmitic acid (B) Lauric acid (D) Glycerol, fatty acids, phosphoric acid and (C) Linolenic acid (D) Palmitoleic acid serine 5. Essential fatty acid: 11. In mammals, the major fat in adipose (A) Linoleic acid (B) Linolenic acid tissues is (C) Arachidonic acid (D) All these (A) Phospholipid (B) Cholesterol 6. The fatty acid present in cerebrosides is (C) Sphingolipids (D) Triacylglycerol

(A) Lignoceric acid (B) Valeric acid 12. Glycosphingolipids are a combination of (C) Caprylic acid (D) Behenic acid (A) Ceramide with one or more sugar residues 7. The number of double bonds in arachi- (B) Glycerol with galactose donic acid is (C) Sphingosine with galactose (A) 1 (B) 2 (D) Sphingosine with phosphoric acid (C) 4 (D) 6 74 MCQs IN BIOCHEMISTRY

13. The importance of phospholipids as 22. Gangliosides derived from glucosyl- constituent of cell membrane is because ceramide contain in addition one or more they possess molecules of (A) Fatty acids (A) Sialic acid (B) Glycerol (B) Both polar and nonpolar groups (C) Diacylglycerol (D) Hyaluronic acid (C) Glycerol 23. ’Drying oil’, oxidized spontaneously by (D) Phosphoric acid atmospheric oxygen at ordinary temperature and forms a hard water 14. In neutral fats, the unsaponificable matter proof material is includes (A) Coconut oil (B) Peanut oil (A) Hydrocarbons (B) Triacylglycerol (C) Rape seed oil (D) Linseed oil (C) Phospholipids (D) Cholsesterol 24. Deterioration of food (rancidity) is due to 15. Higher alcohol present in waxes is presence of (A) Benzyl (B) Methyl (A) Cholesterol (C) Ethyl (D) Cetyl (B) Vitamin E 16. Kerasin consists of (C) Peroxidation of lipids (A) Nervonic acid (B) Lignoceric acid (D) Phenolic compounds (C) Cervonic acid (D) Clupanodonic acid 25. The number of ml of N/10 KOH required to neutralize the fatty acids in the 17. Gangliosides are complex glycosphin- distillate from 5 gm of fat is called golipids found in (A) Reichert-Meissel number (A) Liver (B) Brain (B) Polenske number (C) Kidney (D) Muscle (C) Acetyl number 18. Unsaturated fatty acid found in the cod (D) Non volatile fatty acid number liver oil and containing 5 double bonds is 26. Molecular formula of cholesterol is (A) Clupanodonic acid (A) C H OH (B) Cervonic acid 27 45 (B) C H OH (C) Elaidic acid 29 47 (C) C H OH (D) Timnodonic acid 29 47 (D) C23H41OH 19. Phospholipid acting as surfactant is 27. The cholesterol molecule is (A) Cephalin (B) Phosphatidyl inositol (A) Benzene derivative (C) Lecithin (D) Phosphatidyl serine (B) Quinoline derivative 20. An oil which contains cyclic fatty acids and (C) Steroid once used in the treatment of leprosy is (D) Straight chain acid (A) Elaidic oil (B) Rapeseed oil 28. Salkowski test is performed to detect (C) Lanoline (D) Chaulmoogric oil (A) Glycerol (B) Cholesterol 21. Unpleasant odours and taste in a fat (C) Fatty acids (D) Vitamin D (rancidity) can be delayed or prevented by the addition of 29. Palmitic, oleic or stearic acid ester of cholesterol used in manufacture of (A) Lead (B) Copper cosmetic creams is (C) Tocopherol (D) Ergosterol (A) Elaidic oil (B) Lanoline (C) Spermaceti (D) Chaulmoogric oil FATS AND FATTY ACID METABOLISM 75

30. Dietary fats after absorption appear in 38. An important finding of Fabry’s disease the circulation as is (A) HDL (B) VLDL (A) Skin rash (B) Exophthalmos (C)LDL (D) Chylomicron (C) Hemolytic anemia (D) Mental retardation 31. Free fatty acids are transported in the 39. Gaucher’s disease is due to deficiency of blood the enzyme: (A) Combined with albumin (A) Sphingomyelinase (B) Combined with fatty acid binding protein (B) (C) Galactocerbrosidase (C) Combined with β -lipoprotein (D) β-Galactosidase (D) In unbound free salts 40. Characteristic finding in Gaucher’s 32. Long chain fatty acids are first activated disease is to acetyl-CoA in (A) Night blindness (A) Cytosol (B) Microsomes (B) Renal failure (C) Nucleus (D) Mitochondria (C) Hepatosplenomegaly 33. The enzyme acyl-CoA synthase catalyses (D) Deafness the conversion of a fatty acid of an active 41. An important finding in Neimann-Pick fatty acid in the presence of disease is (A) AMP (B) ADP (A) Leukopenia (C) ATP (D)GTP (B) Cardiac enlargement 34. Carnitine is synthesized from (C) Corneal opacity (A) Lysine and methionine (D) Hepatosplenomegaly (B) Glycine and arginine 42. Fucosidosis is characterized by (C) Aspartate and glutamate (A) Muscle spasticity (B) Liver enlargement (D) Proline and hydroxyproline (C) Skin rash (D) Kidney failure 35. The enzymes of βββ-oxidation are found in 43. Metachromatic leukodystrophy is due to (A) Mitochondria (B) Cytosol deficiency of enzyme: (C) Golgi apparatus (D) Nucleus (A) α-Fucosidase (B) Arylsulphatase A 36. Long chain fatty acids penetrate the inner (C) Ceramidase (D) Hexosaminidase A mitochondrial membrane 44. A significant feature of Tangier disease is (A) Freely (A) Impairment of chylomicron formation (B) As acyl-CoA derivative (B) Hypotriacylglycerolmia (C) As carnitine derivative (C) Absence of Apo-C-II (D) Requiring Na dependent carrier (D) Absence of Apo-C-I 37. An important feature of Zellweger’s 45. A significant feature of Broad Beta disease syndrome is is (A) Hypoglycemia (A) Hypocholesterolemia (B) Accumulation of phytanic acid in tissues (B) Hypotriacylglycerolemia (C) Skin eruptions (C) Absence of Apo-D (D) Accumulation of C26-C38 polyenoic acid in (D) Abnormality of Apo-E brain tissues 76 MCQs IN BIOCHEMISTRY

46. Neonatal tyrosinemia improves on admi- 54. Increased urinary indole acetic acid is nistration of diagnostic of (A) Thiamin (B) Riboflavin (A) Maple syrup urine disease (C) Pyridoxine (D) Ascorbic acid (B) Hartnup disease 47. Absence of phenylalanine hydroxylase (C) Homocystinuia causes (D) Phenylketonuria (A) Neonatal tyrosinemia 55. In glycinuria daily urinary excretion of (B) Phenylketonuria glycine ranges from (C) Primary hyperoxaluria (A) 100–200 mg (B) 300–500 mg (D) Albinism (C) 600–1000 mg (D) 1100–1400 mg 48. Richner-Hanhart syndrome is due to 56. An inborn error, maple syrup urine defect in disease is due to deficiency of the enzyme: (A) Tyrosinase (A) Isovaleryl-CoAhydrogenase (B) Phenylalanine hydroxylase (B) Phenylalnine hydroxylase (C) Hepatic tyrosine transaminase (C) Adenosyl transferase (D) Fumarylacetoacetate hydrolase (D) α-Ketoacid decarboxylase 49. Plasma tyrosine level in Richner-Hanhart 57. Maple syrup urine disease becomes syndrome is evident in extra uterine life by the end of (A) 1–2 mg/dL (B) 2–3 mg/dL (A) First week (B) Second week (C) 4–5 mg/dL (D) 8–10 mg/dL (C) Third week (D) Fourth week 50. Amount of phenylacetic acid excreted in 58. Alkaptonuria occurs due to deficiency of the urine in phenylketonuria is the enzyme: (A) 100–200 mg/dL (B) 200–280 mg/dL (A) Maleylacetoacetate isomerase (C) 290–550 mg/dL (D) 600–750 mg/dL (B) Homogentisate oxidase 51. Tyrosinosis is due to defect in the enzyme: (C) p-Hydroxyphenylpyruvate hydroxylase (A) Fumarylacetoacetate hydrolase (D) Fumarylacetoacetate hydrolase (B) p-Hydroxyphenylpyruvate hydroxylase 59. An important feature of maple syrup (C) Tyrosine transaminase urine disease is (D) Tyrosine hydroxylase (A) Patient can not be treated by dietary 52. An important finding in Histidinemia is regulation (B) Without treatment death, of patient may occur (A) Impairment of conversion of α-Glutamate to by the end of second year of life α-ketoglutarate (C) Blood levels of leucine, isoleucine and serine (B) Speech defect are increased (C) Decreased urinary histidine level (D) Excessive brain damage (D) Patients can not be treated by diet 60. Ochronosis is an important finding of 53. An important finding in glycinuria is (A) Tyrosinemia (A) Excess excretion of oxalate in the urine (B) Tyrosinosis (B) Deficiency of enzyme glycinase (C) Alkaptonuria (C) Significantly increased serum glycine level (D) Richner Hanhart syndrome (D) Defect in renal tubular reabsorption of glycine FATS AND FATTY ACID METABOLISM 77

61. Phrynoderma is a deficiency of 71. The deficiency of both energy and protein (A) Essential fatty acids(B) Proteins causes (C) Amino acids (D) None of these (A) Marasmus (B) Kwashiorkar (C) Diabetes (D) Beri-beri 62. The percentage of linoleic acid in safflow- er oil is 72. Kwashiorkar is characterized by (A) 73 (B) 57 (A) Night blindness (B) Edema (C) 40 (D) 15 (C) Easy fracturability (D) Xerophthalmia 63. The percentage of polyunsaturated fatty 73. A characteristic feature of Kwashiorkar is acids in soyabean oil is (A) Fatty liver (A) 62 (B) 10 (B) Emaciation (C) 3 (D) 2 (C) Low insulin lever 64. The percentage of polyunsaturated fatty (D) Occurrence in less than 1 year infant acids in butter is 74. A characteristic feature of marasmus is (A) 60 (B) 37 (A) Severe hypoalbuminemia (C) 25 (D) 3 (B) Normal epinephrine level 65. Dietary fibre denotes (C) Mild muscle wasting (A) Undigested proteins (D) Low insulin and high cortisol level (B) Plant cell components that cannot be digested by own enzymes 75. Obesity generally reflects excess intake of energy and is often associated with the (C) All plant cell wall components development of (D) All non digestible water insoluble polysaccha- ride (A) Nervousness (B) Non-insulin dependent diabetes mellitus 66. A high fibre diet is associated with re- (C) Hepatitis duced incidence of (D) Colon cancer (A) Cardiovascular disease (B) C.N.S. disease 76. Atherosclerosis and coronary heart (C) Liver disease diseases are associated with the diet: (D) Skin disease (A) High in total fat and saturated fat (B) Low in protein 67. Dietary fibres are rich in (C) High in protein (A) Cellulose (B) Glycogen (D) High in carbohydrate (C) Starch (D) Proteoglycans 77. Cerebrovasular disease and hyperten- 68. Minimum dietary fibre is found in sion is associated with (A) Dried apricot (B) Peas (A) High calcium intake (C) Bran (D) Cornflakes (B) High salt intake 69. A bland diet is recommended in (C) Low calcium intake (A) Peptic ulcer (B) Atherosclerosis (D) Low salt intake (C) Diabetes (D) Liver disease 78. The normal range of total serum bilirubin is 70. A dietary deficiency in both the quantity (A) 0.2–1.2 mg/100 ml and the quality of protein results in (B) 1.5–1.8 mg/100 ml (A) Kwashiorkar (B) Marasmus (C) 2.0–4.0 mg/100 ml (C) Xerophtalmia (D) Liver diseases (D) Above 7.0 mg/100 ml 78 MCQs IN BIOCHEMISTRY

79. The normal range of direct reacting 86. Fecal stercobilinogen is increased in (conjugated) serum bilirubin is (A) Hemolytic jaundice (A) 0–0.1 mg/100 ml (B) Hepatic jaundice (B) 0.1–0.4 mg/100 ml (C) Viral hepatitis (C) 0.4–06 mg/100 ml (D) Obstructive jaundice (D) 0.5–1 mg/100 ml 87. Fecal urobilinogen is increased in 80. The normal range of indirect (unconjugat- ed) bilirubin in serum is (A) Hemolytic jaundice (B) Obstruction of biliary duct (A) 0–0.1 mg/100 ml (C) Extrahepatic gall stones (B) 0.1–0.2 mg/100 ml (D) Enlarged lymphnodes (C) 0.2–0.7 mg/100 ml (D) 0.8–1.0 mg/100 ml 88. A mixture of conjugated and unconjugat- ed bilirubin is found in the circulation in 81. Jaundice is visible when serum bilirubin exceeds (A) Hemolytic jaundice (A) 0.5 mg/100 ml (B) 0.8 mg/100 ml (B) Hepatic jaundice (C) 1 mg/100 ml (D) 2.4 mg/100 ml (C) Obstructive jaundice (D) Post hepatic jaundice 82. An increase in serum unconjugated bilirubin occurs in 89. Hepatocellular jaundice as compared to (A) Hemolytic jaundice pure obstructive type of jaundice is char- acterized by (B) Obstructive jaundice (C) Nephritis (A) Increased serum alkaline phosphate, LDH and (D) Glomerulonephritis ALT (B) Decreased serum , LDH 83. One of the causes of hemolytic jaundice is and ALT (A) G-6 phosphatase deficiency (C) Increased serum alkaline phosphatase and (B) Increased conjugated bilirubin decreased levels of LDH and ALT (C) Glucokinase deficiency (D) Decreased serum alkaline phosphatase and (D) Phosphoglucomutase deficiency increased serum LDH and ALT 84. Increased urobilinogen in urine and 90. Icteric index of an normal adult varies absence of bilirubin in the urine suggests between (A) Obstructive jaundice (A) 1–2 (B) 2–4 (B) Hemolytic jaundice (C) 4–6 (D) 10–15 (C) Viral hepatitis 91. Clinical jaundice is present with an icteric (D) Toxic jaundice index above 85. A jaundice in which serum alanine (A) 4 (B) 8 transaminase and alkaline phosphatase (C) 10 (D) 15 are normal is (A) Hepatic jaundice 92. Normal quantity of urobilinogen excreted in the feces per day is about (B) Hemolytic jaundice (C) Parenchymatous jaundice (A) 10–25 mg (B) 50–250 mg (D) Obstructive Jaundice (C) 300–500 mg (D) 700–800 mg FATS AND FATTY ACID METABOLISM 79

93. Fecal urobilinogen is decreased in 100. The ability of liver to remove a dye like (A) Obstruction of biliary duct BSP from the blood suggests a normal (B) Hemolytic jaundice (A) Excretory function (C) Excess fat intake (B) Detoxification function (D) Low fat intake (C) Metabolic function (D) Circulatory function 94. A complete absence of fecal urobilinogen is strongly suggestive of 101. Removal of BSP dye by the liver involves conjugation with (A) Obstruction of bile duct (A) Thiosulphate (B) Hemolytic jaundice (B) Glutamine (C) Intrahepatic cholestasis (C) Cystein component of glutathione (D) Malignant obstructive disease (D) UDP glucuronate 95. Immediate direct Vanden Bergh reaction 102. Normal value of plasma total proteins indicates varies between (A) Hemolytic jaundice (A) 3–4 gm/100ml (B) 6–8 gm/100ml (B) Hepatic jaundice (C) 10–12 gm/100ml (D) 14–16 gm/100ml (C) Obstructive jaundice 103. A decrease in albumin with increased (D) Megalobastic anemia production of other unidentified proteins 96. The presence of bilirubin in the urine which migrate in βββ, γγγ region suggests without urobilinogen suggests (A) Cirrhosis of liver (A) Obstructive jaundice (B) Nephrotic syndrome (B) Hemolytic jaundice (C) Infection (C) Pernicious anemia (D) Chronic lymphatic leukemia (D) Damage to the hepatic parenchyma 104. In increase in ααα2-Globulin with loss of 97. Impaired galactose tolerance test suggests albumin in urine suggests (A) Defect in glucose utilisation (A) Primary immune deficiency (B) Liver cell injury (B) Nephrotic syndrome (C) Cirrhosis of liver (C) Renal defect (D) Multiple myeloma (D) Muscle injury 105. The normal levels of prothrombin time is 98. Increased serum ornithine carabamoyl about transferase activity is diagnostic of (A) 2 sec (B) 4 sec (A) Myocardial infarction (C) 14 sec (D) 10–16 sec (B) Hemolytic jaundice (C) Bone disease 106. In obstructive jaundice prothrombin time (D) Acute viral hepatitis (A) Remains normal (B) Decreases 99. The best known and most frequently used (C) Responds to vit K and becomes normal test of the detoxicating functions of liver is (D) Responds to vit K and increases (A) Hippuric acid test 107. In parenhymatous liver disease the proth- (B) Galactose tolerance test rombin time (C) Epinephrine tolerance test (A) Remains normal (B) Increases (D) Rose Bengal dye test (C) Decreases (D) Responds to Vit K 80 MCQs IN BIOCHEMISTRY

108. Urea clearance test is used to determine 116. Measurement of insulin clearance test is the a measure of (A) Glomerular filtration rate (A) Glomerular filtration rate (B) Renal plasma flow (B) Filtration factor (C) Ability of kidney to concentrate the urine (C) Renal plasma flow (D) Measurement of tubular mass (D) Tubular secretory mass 109. The formula to calculate maximum urea 117. The polysaccharide insulin is UV× clearance is , where U denotes (A) Filtered at the glomerulus but neither secreted B nor reabsorbed by the tubule (A) Concentration of urea in urine in gm/24 hr (B) Filtered at the glomerulus and secreted by (B) Concentration of urea in urine in mg/100 ml the tubule (C) Concentration of urea in blood in mg/100 ml (C) Filtered at the glomerulus and reabsorbed by (D) Volume of urine in ml/mt the tubule (D) Filtered at the glomerulus, secreted and 110. Average maximum urea clearance is reabsorbed by the tubule (A) 30 ml (B) 50 ml 118. Normal insulin clearance is (C) 75 ml (D) 90 ml (A) 40 ml/1.73 sqm (B) 60 ml/1.73 sqm 111. The average normal value for standard (C) 80 ml/1.73 sqm (D) 120 ml/1.73 sqm urea clearance is 119. Creatinine EDTA clearance is a test to (A) 20 ml (B) 30 ml measure (C) 40 ml (D) 54 ml (A) Renal plasma flow 112. Urea clearance is lowered in (B) Filtration fraction (A) Acute nephritis (C) Glomerular filtration rate (B) Pneumonia (D) Tubular function (C) Early stage of nephritic syndrome 120. The end products of saponification: (D) Benign hypertension (A) glycerol (B) acid 113. Glomerular filtration rate can be measured (C) soap (D) Both (A) and (C) by 121. The normal PAH clearance for a surface (A) Endogenous creatinine clearance area of 1.73 sqm. is (B) Para-aminohippurate test (A) 200 ml/min (B) 300 ml/min (C) Addis test (C) 400 ml/min (D) 574 ml/min (D) Mosenthal test 122. Para amino hippurate is 114. At normal levels of creatinine in the blood, (A) Filtered at glomeruli and secreted by the this metabolite is tubules (A) Filtered at the glomerulus but not secreted nor (B) Filtered at glomeruli and not secreted by the reabsorbed by the tubule tubules (B) Secreted by the tubule (C) Filtered at glomeruli and reabsorbed completely (C) Reabsorbed by the tubule (D) Not removed completely during a single (D) Secreted and reabsorbed by tubule circulation of the blood through the kidney. 115. The normal values for creatinine clearance 123. The Tm for PAH i.e the maximal secretory varies from capacity of the tubule for PAH can be used (A) 20–40 ml/min (B) 40–60 ml/min to gavge the (C) 70–85 ml/min (D) 95–105 ml/min (A) Extent of tubular damage FATS AND FATTY ACID METABOLISM 81

(B) Impairment of the capacity of the tubule to 132. Triglycerides are perform osmotic work (A) Heavier than water (C) Impairment of renal plasma flow (B) Major constituents of membranes (D) Glomerular filtration rate (C) Non-polar 124. The normal Tm in mg/min/1.73 sqm for (D) Hydrophilic PAH is 133. Cerebronic acid is present in (A) 20 (B) 40 (A) Glycerophospholipids (C) 60 (D) 80 (B) Sphingophospholipids 125. The normal range of filtration factor in an (C) Galactosyl ceramide adult is (D) Gangliosides (A) 0.10–0.15 (B) 0.16–0.21 134. Acylsphingosine is also known as (C) 0.25–0.30 (D) 0.35–0.40 (A) Sphingomyelin (B) Ceramide 126. The filtration factor tends to be normal in (C) Cerebroside (D) Sulphatide (A) Early essential hypertension 135. The highest phospholipids content is (B) Malignant phase of hypertension found in (C) Glomerulonephritis (A) Chylomicrons (B) VLDL (D) Acute nephritis (C) LDL (D) HDL 127. The filtration factor is increased in 136. The major lipid in chylomicrons is (A) Glomerulonephritis (B) Malignant phase of hypertension (A) Triglycerides (B) Phospholipids (C) Early essential hypertension (C) Cholesterol (D) Free fatty acids (D) Acute nephritis 137. Number of carbon atoms in cholesterol is 128. The filtration factor is decreased in (A) 17 (B) 19 (A) Glomerulonephritis (C) 27 (D) 30 (B) Early essential hypertension 138. The lipoprotein richest in cholesterol is (C) Malignant phase of hypertension (A) Chylomicrons (B) VLDL (D) Starvation (C) LDL (D) HDL 129. Excretion of phenolsulphanpthalein (PSP) 139. The major storage form of lipids is reflects (A) Esterified cholesterol (A) Glomerulonephritis (B) Glycerophospholipids (B) Maximaltabular excretory capacity (C) Triglycerides (C) Filtration factor (D) Sphingolipids (D) Renal plasma flow 140. Cerebonic acid is present in 130. Which of the following is a polyunsatu- (A) Triglycerides rated fatty acid? (B) Cerebrosides (A) Palmitic acid (B) Palmitoleic acid (C) Esterified cholestrol (C) Linoleic acid (D) Oleic acid (D) Sphingomyelin 131. Which of the following is omega-3 polyun- 141. The nitrogenous base in lecithin is saturated fatty acid? (A) Ethanolamine (B) Choline (A) Linoleic acid (B) α-Linolenic acid (C) Serine (D) Betaine (C) γ-Linolenic acid (D) Arachidonic acid 82 MCQs IN BIOCHEMISTRY

142. All the following are omega-6-fatty acids 152. De hovo synthesis of fatty acids occurs in except (A) Cytosol (B) Mitochondria (A) Linoleic acid (B) α-Linolenic acid (C) Microsomes (D) All of these (C) γ-Linolenic acid (D) Arachidonic acid 153. Acyl Carrier Protein contains the vitamin: 143. All the following have 18 carbon atoms except (A) Biotin (B) Lipoic acid (C) Pantothenic acid (D) Folic acid (A) Linoleic acid (B) Linolenic acid (C) Arachidonic acid (D) Stearic acid 154. Which of the following is required as a reductant in fatty acid synthesis? 144. A 20-carbon fatty acid among the follow- ing is (A) NADH (B) NADPH

(A) Linoleic acid (B) α -Linolenic acid (C) FADH2 (D) FMNH2 (C) β -Linolenic acid (D) Arachidonic acid 155. Hepatic liponenesis is stimulated by: 145. Triglycerides are transported from liver to (A) cAMP (B) Glucagon extrahepatic tissues by (C) Epinephrine (D) Insulin (A) Chylomicrons (B) VLDL 156. De novo synthesis of fatty acids requires (C) HDL (D) LDL all of the following except 146. Cholesterol is transported from liver to (A) Biotin (B) NADH extrahepatic tissues by (C) Panthothenic acid (D) ATP (A) Chylomicrons (B) VLDL (C) HDL (D) LDL 157. Acetyl CoA carboxylase regulates fatty acid synthesis by which of the following 147. Elevated plasma level of the following mechanism? projects against atherosclerosis: (A) Allosteric regulation (A) Chylomicrons (B) VLDL (B) Covalent modification (C) HDL (D) LDL (C) Induction and repression 148. All the following amino acids are non- (D) All of these essential except 158. βββ-Oxidation of fatty acids requires all the (A) Alanine (B) Histidine following coenzymes except (C) Cysteine (D) Proline (A) CoA (B) FAD 149. Sulphydryl group is present in (C) NAD (D) NADP (A) Cysteine (B) Methionine 159. Which of the following can be oxidized (C) Both (A) and (B) (D) None of these by βββ-oxidation pathway? 150. Oligosaccharide-pyrophosphoryl dolichol (A) Saturated fatty acids is required for the synthesis of (B) Monosaturated fatty acids (A) N-linked glycoproteins (C) Polyunsaturated fatty acids (B) O-linked glycoproteins (D) All of these (C) GPI-linked glycoproteins (D) All of these 160. Propionyl CoA is formed on oxidation of 151. In N-linked glycoproteins, oligosaccharide (A) Monounsaturated fatty acids is attached to protein through its (B) Polyunsaturated fatty acids (A) Asparagine residue (B) Glutamine residue (C) Fatty acids with odd number of carbon atoms (C) Arginine residue (D) Lysine residue (D) None of these FATS AND FATTY ACID METABOLISM 83

161. An enzyme required for the synthesis of 169. Thromboxanes cause ketone bodies as well as cholesterol is (A) Vasodilation (A) Acetyl CoA carboxylase (B) Bronchoconstriction (B) HMG CoA synthetase (C) Platelet aggregation (C) HMG CoA reductase (D) All of these (D) HMG CoA 170. Prostaglandins lower camp in 162. Ketone bodies are synthesized in (A) Adipose tissue (B) Lungs (A) Adipose tissue (B) Liver (C) Platelets (D) Adenohypophysis (C) Muscles (D) Brain 171. Slow reacting Substance of Anaphylaxis 163. All the following statements about ketone is a mixture of bodies are true except (A) Prostaglandins (B) Prostacyclins (A) Their synthesis increases in diabetes mellitus (C) Thromboxanes (D) Leukotrienes (B) They are synthesized in mitchondria (C) They can deplete the alkali reserve 172. Dipalmitoyl lecithin acts as (D) They can be oxidized in the liver (A) Platelet activating factor (B) Second messenger for hormones 164. All the following statements about carnitine are true except (C) Lung surfactant (D) Anti-ketogenic compound (A) It can be synthesised in the human body (B) It can be synthesized from methionine and lysine 173. Reichert-Meissl number: (C) It is required for transport of short chain fatty (A) 0.1 N KOH (B) 0.5 KOH acids into mitochondria (C) 0.1 N NaOH (D) 0.5 NaOH (D) Its deficiency can occur due to haemodialysis 174. In glycerophospholipids, a polyunsaturat- 165. Which of the following can be synthesized ed fatty acid is commonly attached to which in the human body if precurors are of the following carbon atom of glycerol? available? (A) Carbon 1 (B) Carbon 2 (A) Oleic acid (B) Palmitoleic acid (C) Both (A) and (B) (D) None of these (C) Arachidonic acid (D) All of these 175. Lysolecithin is formed from lecithin by 166. All the following can be oxidized by βββ- removal of oxidation except (A) Fatty acid from position 1 (A) Palmitic acid (B) Fatty acid from position 2 (B) Phytanic acid (C) Phosphorylcholine (C) Linoleic acid (D) Choline (D) Fatty acids having an odd number of carbon atoms 176. Sphingosine is synthesized from 167. Anti-inflammatory corticosteroids inhibit (A) Palmitoyl CoA and Choline the synthesis of (B) Palmitoyl CoA and ethanolamine (A) Leukotrienes (B) Prostaglandins (C) Palmitoyl CoA and serine (C) Thromboxanes (D) All of these (D) Acetyl CoA and choline 168. Diets having a high ratio of polyunsa- 177. For synthesis of sphingosine, all the turated: saturated fatty acids can cause following coenzymes are required except (A) Increase in serum triglycerides (A) Pyridoxal phosphate (B) Decrease in serum cholesterol (B) NADPH (C) Decrease in serum HDL (C) FAD (D) Skin lesions (D) NAD 84 MCQs IN BIOCHEMISTRY

178. Cerebrosides contain all the following 188. Activated lecithin cholesterol acyl trans- except ferase is essential for the conversion of (A) Galactose (B) Sulphate (A) VLDL remnants into LDL (C) Sphingosine (D) Fatty acid (B) Nascent HDL into HDL (C) HDL into HDL 179. Niemann-Pick disease results from 2 3 deficiency of (D) HDL3 into HDL2 (A) Ceramidase (B) Sphingomyelinase 189. Fatty liver may be caused by (C) Arylsulphatase A (D) Hexosaminidase A (A) Deficiency of methionine 180. Chylomicron remnants are catabolised in (B) Puromycin (C) Chronic alcoholism (A) Intestine (B) Adipose tissue (D) All of these (C) Liver (D) Liver and intestine 190. converts ethanol 181. VLDL remnant may be converted into into (A) VLDL (B) LDL (A) Acetyl CoA (B) Acetaldehyde (C)HDL (D) Chylomicrons (C) Acetate (D) CO2 and H2O 182. Receptors for chylomicron remnants are 191. Lipids are stored in the body mainly in (A) Apo A specific (B) Apo B-48 specific the form of (C) Apo C specific (D) Apo E specific (A) Phospholipids (B) Glycolipids 183. LDL receptor is specific for (C) Triglycerides (D) Fatty acids (A) Apo B-48 and Apo B 100 192. Lipid stores are mainly present in (B) Apo B-48 and Apo E (A) Liver (B) Brain (C) Apo B-100 and Apo D (C) Muscles (D) Adipose tissue (D) Apo B-100 and apo D 193. Glycerol is converted into glycerol-3- 184. Nascent HDL of intestinal origin lacks phosphate by (A) Apo A (B) Apo C (A) Thiokinase (B) (C) Apo E (D) Apo C and Apo E (C) (D) All of these 185. HDL is synthesized in 194. In adipose tissue, glycerol-3-phosphate (A) Adipose tissue (B) Liver required for the synthesis of triglycerides (C) Intestine (D) Liver and intestine comes mainly from (A) Hydrolysis of pre-existing triglycerides 186. Nascent HDL of intestinal origin acquires Apo C and Apo E from (B) Hydrolysis of phospholipids (C) Dihydroxyacetone phosphate formed in (A) Chylomicrons glycolysis (B) VLDL (D) Free glycerol (C) LDL (D) HDL of the hepatic origin 195. Glycerol released from adipose tissue by hydrolysis of triglycerides is mainly 187. Heparin releasable hepatic lipase converts (A) Taken up by liver (A) VLDL remnants into LDL (B) Taken up by extrahepatic tissues (B) Nascent HDL into HDL (C) Reutilised in adipose tissue (C) HDL2 into HDL3 (D) Excreted from the body (D) HDL3 into HDL2 FATS AND FATTY ACID METABOLISM 85

196. Free glycerol cannot be used for triglyceride 204. Oxidation of fatty acids occurs synthesis in (A) In the cytosol (A) Liver (B) Kidney (B) In the matrix of mitochondria (C) Intestine (D) Adipose tissue (C) On inner mitochondrial membrane 197. Adipose tissue lacks (D) On the microsomes (A) Hormone-sensitive lipase 205. Activation of fatty acids requires all the (B) Glycerol kinase following except (C) cAMP-dependent protein kinase (A) ATP (B) Coenzyme A (D) Glycerol-3-phosphate dehydrogenase (C) Thiokinase (D) Carnitine 198. A digestive secretion that does not contain 206. Mitochondrial thiokinase acts on any digestive enzyme is (A) Short chain of fatty acids (A) Saliva (B) Gastric juice (B) Medium chain fatty acids (C) Pancreatic juice (D) Bile (C) Long chain fatty acids (D) All of these 199. Saliva contains a lipase which acts on triglycerides having 207. Carnitine is required for the transport of (A) Short chain fatty acids (A) Triglycerides out of liver (B) Medium chain fatty acids (B) Triglycerides into mitochondria (C) Long chain fatty acids (C) Short chain fatty acids into mitochondria (D) All of these (D) Long chain fatty acids into mitochondria 200. Salivary lipase hydrolyses the ester bond 208. Carnitine acylcarnitine is at present (A) Position 1 of triglycerides (A) In the inner mitochondrial membrane (B) Position 2 of triglycerides (B) In the mitochondrial matrix (C) Position 3 of triglycerides (C) On the outer surface of inner mitochondrial membrane (D) All of these (D) On the inner surface of inner mitochondrial 201. Salivary lipase converts dietary trigly- membrane cerides into 209. Net ATP generation on complete oxidation (A) Diglycerides and fatty acids of stearic acid is (B) Monoglycerides and fatty acids (A) 129 (B) 131 (C) Glycerol and fatty acids (C) 146 (D) 148 (D) All of these 210. Propionyl CoA formed oxidation of fatty 202. Pancreatic lipase requires for its activity: acids having an odd number of carbon (A) Co-lipase (B) Bile salts atoms is converted into (C) Phospholipids (D) All of these (A) Acetyl CoA (B) Acetoacetyl CoA 203. Pancreatic lipase converts triacylglycerols into (C) D-Methylmalonyl CoA (D) Butyryl CoA (A) 2, 3-Diacylglycerol (B) 1-Monoacylglycerol 211. ααα-Oxidation of fatty acids occurs mainly in (C) 2-Monoacylglycerol (A) Liver (B) Brain (D) 3-Monoacylglycerol (C) Muscles (D) Adipose tissue 86 MCQs IN BIOCHEMISTRY

212. Refsum’s disease results from a defect in 220. During each cycle of βββ-oxidation the following pathway except (A) One carbon atom is removed from the (A) Alpha-oxidation of fatty acids carboxyl end of the fatty acid (B) Beta-oxidation of fatty acids (B) One carbon atom is removed from the methyl (C) Gamma-oxidation of fatty acids end of the fatty acid (C) Two carbon atoms are removed from the (D) Omega-oxidation of fatty acids carboxyl end of the fatty acid 213. The end product of omega-oxidation of (D) Two carbon atoms are removed from the fatty acids having an even number of methyl end of the fatty acid carbon atoms is 221. Net generation of energy on complete (A) Adipic acid (B) Suberic acid oxidation of palmitic acid is (C) Both (A) and (B) (D) None of these (A) 129 ATP equivalents 214. De novo synthesis of fatty acids is (B) 131 ATP equivalents catalysed by a multi-enzyme complex (C) 146 ATP equivalents which contains (D) 148 ATP equivalents (A) One-SH group (B) Two-SH groups 222. Net generation of energy on complete (C) Three-SH groups (D) Four-SH groups oxidation of a 17-carbon fatty acid is 215. Fat depots are located in (A) Equal to the energy generation from a 16-carbon fatty acid (A) Intermuscular (B) Equal to the energy generation from an (B) Mesentary 18-carbon fatty acid (C) Omentum (C) Less than the energy generation from a (D) All of these 16-carbon fatty acid 216. Salivary lipase is secreted by (D) In between the energy generation from a 16-carbon fatty acid and an 18-carbon fatty (A) Parotid glands acid (B) Sub-maxillary glands 223. Net energy generation on complete (C) Dorsal surface of tongue oxidation of linoleic acid is (D) None of these (A) 148 ATP equivalents 217. Co-lipase is a (B) 146 ATP equivalents (A) Bile salt (B) Vitamin (C) 144 ATP equivalents (C) Protein (D) Phospholipid (D) 142 ATP equivalents 218. Plasma becomes milky 224. Extramitochondrial synthesis of fatty acids occurs in (A) Due to high level of HDL (B) Due to high level of LDL (A) Mammary glands (B) Lungs (C) During fasting (C) Brain (D) All of these (D) After a meal 225. One functional sub-unit of multi-enzyme complex for de novo synthesis of fatty 219. Mitochondrial membrane is permeable to acids contains (A) Short chain fatty acids (A) One —SH group (B) Medium chain fatty acids (B) Two —SH groups (C) Long chain fatty acids (C) Three —SH groups (D) All of these (D) Four —SH groups FATS AND FATTY ACID METABOLISM 87

226. NADPH required for fatty acid synthesis 234. Lipo- is required for the syn- can come from thesis of (A) Hexose monophosphate shunt (A) Prostaglandins (B) Leukotrienes (B) Oxidative decarboxylation of malate (C) Thromboxanes (D) All of these (C) Extramitochondrial oxidation of isocitrate 235. All of the following statements about (D) All of these multiple sclerosis are true except 227. Fatty liver may be prevented by all of the (A) There is loss of phospholipids from white matter following except (B) There is loss of sphingolipids from white matter (A) Choline (B) Betaine (C) There is loss of esterified cholesterol from white matter (C) Methionine (D) Ethionine (D) White matter resembles gray matter in 228. Human desaturase enzyme system composition cannot introduce a double bond in a fatty 236. After entering cytosol, free fatty acids are acid beyond bound to (A) Carbon 9 (B) Carbon 6 (A) Albumin (B) Globulin (C) Carbon 5 (D) Carbon 3 (C) Z-protein (D) None of these 229. Which of the following lipid is absorbed 237. Release of free fatty acids from adipose actively from intestines? tissue is increased by all of the following (A) Glycerol except (B) Cholesterol (A) Glucagon (B) Epinephrine (C) Monoacylglycerol (C) Growth hormone (D) Insulin (D) None of these 238. All the following statements about brown adipose tissue are true except 230. C22 and C24, fatty acids required for the synthesis of sphingolipids in brain are (A) It is rich in cytochromes formed by (B) It oxidizes glucose and fatty acids (A) De novo synthesis (C) Oxidation and phosphorylation are tightly (B) Microsomal chain elongation coupled in it (C) Mitochondrial chain elongation (D) Dinitrophenol has no effect on it (D) All of these 239. Lovastatin and mevastatin lower 231. Sphingomyelins: (A) Serum triglycerides (A) Phospholipids (B) Nitrolipids (B) Serum cholesterol (C) Alcohols (D) None of these (C) Serum phospholipids (D) All of these 232. All of the following statements about hypoglycin are true except 240. Lovastatin is a (A) It is a plant toxin (A) Competitive inhibitor of acetyl CoA carboxylase (B) It causes hypoglycaemia (B) Competitive inhibitor of HMG CoA synthetase (C) It inhibits oxidation of short chain fatty acids (C) Non-competitive inhibitor of HMG CoA reductase (D) It inhibits oxidation of long chain fatty acids (D) Competitive inhibitor of HMG CoA reductase 233. Synthesis of prostaglandins is inhibited by 241. Abetalipoproteinaemia occurs due to a block in the synthesis of (A) Glucocorticoids (B) Aspirin (A) Apoprotein A (B) Apoprotein B (C) Indomethacin (D) All of these (C) Apoprotein C (D) Cholesterol 88 MCQs IN BIOCHEMISTRY

242. All of the following statements about (B) Saturated fatty acids Tangier disease are true except (C) Integral proteins (A) It is a disorder of HDL metabolism (D) Cholesterol (B) Its inheritance is autosomal recessive 251. Transition temperature of membranes (C) Apoproteins A-I and A-II are not synthesised may be affected by the following consti- (D) Plasma HDL is increased tuent of membranes: 243. Genetic deficiency of lipoprotein lipase (A) Peripheral proteins (B) Integral proteins causes hyperlipoproteinaemia of following (C) Cholesterol (D) Oligosachharides type: 252. Acetyl CoA formed from pyruvate can be (A) Type I (B) Type IIa used for the synthesis of all the following (C) Type IIb (D) Type V except 244. Chylomicrons are present in fasting (A) Glucose (B) Fatty acids blood samples in hyperlipoproteinaemia (C) Cholesterol (D) Steroid hormones of following types: 253. Which of the following can be used as a (A) Types I and IIa (B) Types IIa and IIb source of energy in extrahepatic tissues? (C) Types I and V (D) Types IV and V (A) Acetoacetate (B) Acetone 245. Glutathione is a constituent of (C) Both (A) and (B) (D) None of these

(A) Leukotriene A4 (B) Thromboxane A1 254. Anti-inflammatory corticosteroids inhibit

(C) Leukotriene C4 (D) None of these (A) Phospholipase A1 (B) Phospholipase A2 246. Prostaglandins are inactivated by (C) Cyclo-oxygenase (D) Lipo-oxygenase (A) 15-Hydroxyprostaglandin dehydrogenase 255. Cyclo-oxygenase is involved in the (B) Cyclo-oxygenase synthesis of (C) Lipo-oxygenase (A) Prostaglandins (B) Thromboxanes (D) None of these (C) Both (A) and (B) (D) None of these 247. Phenylbutazone and indomethacin 256. Leukotrienes cause inhibit (A) Increase in capillary permeability (A) Phospholipase A (B) Phospholipase A 1 2 (B) Aggregation of platelets (C) Cyclo-oxygenase (D) Lipo-oxygenase (C) Bronchodilatation 248. Prostaglandins stimulate (D) None of these (A) Aggregation of platelets 257. Prostaglandins decrease all of the following (B) Lipolysis in adipose tissue except (C) Bronchodilatation (A) Gastric acid secretion (D) Gastric acid secretion (B) Blood pressure 249. For extramitochondrial fatty acid synthesis, (C) Uterine contraction acetyl CoA may be obtained from (D) Platelet aggregation (A) Citrate (B) Isocitrate 258. Hypocholesterolaemia can occur in (C) Oxaloacetate (D) Succinate (A) Hyperthyroidism 250. Fluidity of membranes is increased by (B) Nephrotic syndrome the following constituent except (C) Obstructive jaundice (A) Polyunsaturated fatty acids (D) Diabetes mellitus FATS AND FATTY ACID METABOLISM 89

259. De novo synthesis and oxidation of fatty 266. The enzyme deficient in Fabry’s disease is acids differ in the following respect: (A) α-Galactosidase (B) β-Galactosidase (A) Synthesis occurs in cytosol and oxidation in (C) α-Glucosidase (D) β-Glucosidase mitochondria (B) Synthesis is decreased and oxidation 267. Highest protein content amongst the increased by insulin following is present in (C) NADH is required in synthesis and FAD in (A) Wheat (B) Rice oxidation (C) Pulses (D) Soyabean (D) Malonyl CoA is formed during oxidation but 268. Daily protein requirement of an adult man not during synthesis is 260. Free fatty acids released from adipose (A) 0.5 gm/kg of body weight tissue are transported in blood by (B) 0.8 gm/kg of body weight (A) Albumin (B) VLDL (C) 1.0 gm/kg of body weight (C) LDL (D) HDL (D) 1.5 gm/kg of body weight

261. β -Galactosidase is deficient in 269. Daily protein requirement of an adult woman is (A) Fabry’s disease (A) 0.5 gm/kg of body weight (B) Krabbe’s disease (B) 0.8 gm/kg of body weight (C) Gaucher’s disease (C) 1.0 gm/kg of body weight (D) Metachromatic leukodystrophy (D) 1.5 gm/kg of body weight 262. The enzyme deficient in metachromatic 270. Cysteine can partially meet the require- leukodystrophy is ment of (A) Arylsulphatase A (B) Hexosaminidase A (A) Phenylalanine (B) Threonine (C) Ceramidase (D) Sphingomyelinase (C) Methionine (D) None of these 263. All of the following statements about 271. Invisible fat is present in generalized gangliosidosis are true except (A) Milk (B) Coconut oil (C) Groundnut oil (D) Hydrogenated oils (A) It results from deficiency of GM1-β- Gangliosidase 272. Visible fat is present in

(B) Breakdown of GM1 ganglioside is impaired (A) Milk (B) Pulses (C) GM2 ganglioside accumulates in liver and (C) Coconut oil (D) Egg yolk elsewhere 273. Fat content of eggs is about (D) It leads to mental retardation (A) 7% (B) 10% 264. Hexosaminidase A is deficient in (C) 13% (D) 16% (A) Tay-Sachs disease 274. Fat content of pulses is about (B) Gaucher’s disease (C) Niemann-Pick disease (A) 5% (B) 10% (D) Fabry’s disease (C) 15% (D) 20% 265. Mental retardation occurs in 275. Predominant fatty acids in meat are (A) Tay-Sachs disease (A) Saturated (B) Monounsaturated (B) Gaucher’s disease (C) Polyunsaturated (C) Niemann-Pick disease (D) Mono and poly-unsaturated (D) All of these 90 MCQs IN BIOCHEMISTRY

276. Oils having more than 50 % polyunsatu- 286. In Ames’ assay, addition of a carcinogen rated fatty acids include all of the follow- to the culture medium allows S. typhimu- ing except rium to grow (A) Groundnut oil (B) Soyabean oil (A) In the presence of histidine (C) Sunflower oil (D) Safflower oil (B) In the presence of arginine 277. Cholesterol is present in all of the follow- (C) In the absence of histidine ing except (D) In the absence of arginine (A) Egg (B) Fish 287. In Ames’ assay, liver homogenate is (C) Milk (D) Pulses included in the culture medium because 278. Which of the following has the highest (A) It converts pro-carcinogens into carcinogens cholesterol content? (B) Liver can metabolise histidine (A) Meat (B) Fish (C) Salmonella mainly infects liver (C) Butter (D) Milk (D) Liver is very susceptible to cancer 279. Which of the following has the highest cholesterol content? 288. Bile pigments are present and urobilino- gen absent in urine in (A) Egg yolk (B) Egg white (C) Meat (D) Fish (A) Haemolytic jaundice (B) Hepatocellular jaundice 280. The following contains the least cholesterol: (C) Obstructive jaundice (D) Crigler-Najjar syndrome (A) Milk (B) Meat (C) Butter (D) Cheese 289. Bile pigments are absent and urobilino- gen increased in urine in 281. Which of the following constitutes fibre or roughage in food? (A) Haemolytic jaundice (A) Cellulose (B) Pectin (B) Hepatocellular jaundice (C) Inulin (D) All of these (C) Obstructive jaundice 282. The starch content of wheat is about (D) Rotor’s syndrome (A) 50% (B) 60% 290. In obstructive jaundice, urine shows (C) 70% (D) 80% (A) Absence of bile pigments and urobilinogen 283. The starch content of pulses is about (B) Presence of bile pigments and urobilinogen (A) 50% (B) 60% (C) Absence of bile pigments and presence of (C) 70% (D) 80% urobilinogen (D) Presence of bile pigments and absence of 284. A significant source of starch among urobilinogen vegetables is (A) Radish (B) Spinach 291. In haemolytic jaundice, urine shows (C) Potato (D) Cauliflower (A) Absence of bile pigments and urobilinogen 285. The cyclic ring present in all the steroids: (B) Presence of bile pigments and urobilinogen (C) Absence of bile pigments and presence of (A) Cyclopentano perhydrophenanthrene urobilinogen (B) Nitropentano (D) Presence of bile pigments and absence of (C) both (A) and (B) urobilinogen (D) None of these FATS AND FATTY ACID METABOLISM 91

292. Serum albumin may be decreased in 301. All the following statements about (A) Haemolytic jaundice obstructive jaundice are true except (B) Hepatocellular jaundice (A) Prothrombin time may be prolonged due to (C) Obstructive jaundice impaired absorption of vitamin K (D) All of these (B) Serum alkaline phosphatase may be raised due to increased release of the enzyme from 293. Normal range of serum albumin is liver cells (A) 2.0–3.6 gm/dl (B) 2.0–3.6 mg/dl (C) Bile salts may enter systemic circulation due (C) 3.5–5.5 gm/dl (D) 3.5–5.5 mg/dl to biliary obstruction (D) There is no defect in conjugation of bilirubin 294. Normal range of serum globulin is (A) 2.0–3.6 mg/dl (B) 2.0–3.6 gm/dl 302. A test to evaluate detoxifying function of liver is (C) 3.5–5.5 mg/dl (D) 3.5–5.5 gm/dl (A) Serum albumin: globulin ratio 295. Serum albumin: globulin ratio is altered in (B) Galactose tolerance test (A) Gilbert’s disease (B) Haemolytic jaundice (C) Hippuric acid test (C) Viral hepatitis (D) Stones in bile duct (D) Prothrombin time 296. Esterification of cholesterol occurs mainly 303. Hippuric acid is formed from in (A) Benzoic acid and alanine (A) Adipose tissue (B) Liver (B) Benzoic acid glycine (C) Muscles (D) Kidneys (C) Glucuronic acid and alanine 297. Galactose intolerance can occur in (D) Glucuronic acid and glycine (A) Haemolytic jaundice 304. An enzyme which is excreted in urine is (B) Hepatocellular jaundice (A) dehydrogenase (C) Obstructive jaundice (B) Amylase (D) None of these (C) Ornithine transcarbamoylase 298. Prothrombin is synthesised in (D) None of these (A) Erythrocytes 305. Serum gamma glutamyl transpeptidase (B) Reticulo-endothelial cells is raised in (C) Liver (A) Haemolytic jaundice (D) Kidneys (B) Myocardial infarction 299. Prothrombin time remains prolonged (C) Alcoholic hepatitis even after parenterals administration of (D) Acute cholecystitis vitamin K in 306. Oliguria can occur in (A) Haemolytic jaundice (A) Diabetes mellitus (B) Liver damage (B) Diabetes insipidus (C) Biliary obstruction (C) Acute glomerulonephritis (D) Steatorrhoea (D) Chronic glomerulonephritis 300. All the following statements about 307. Urea clearance is the obstructive jaundice are true except (A) Amount of urea excreted per minute (A) Conjugated bilirubin in serum is normal (B) Amount of urea present in 100 ml of urine (B) Total bilirubin in serum is raised (C) Volume of blood cleared of urea in one minute (C) Bile salts are present in urine (D) Amount of urea filtered by glomeruli in one (D) Serum alkaline phosphatase is raised minute 92 MCQs IN BIOCHEMISTRY

308. Inulin clearance is a measure of 316. Esters of fatty acids with higher alcohols (A) Glomerular filtration rate other than glycerol are said to be (B) Tubular secretion flow (A) Waxes (B) Fats (C) Tubular reabsorption rate (C) Both (A) and (B) (D) None of these (D) Renal plasma flow 317. The combination of an amino alcohol, 309. Phenolsulphonephthalein excretion test is fatty acid and sialic acid form an indicator of (A) Phospholipids (B) Sulpholipids (A) Glomerular filtration (C) Glycolipids (D) Aminolipids (B) Tubular secretion 318. Hydrolysis of fats by alkali is called (C) Tubular reabsorption (A) Saponification number (D) Renal blood low (B) Saponification 310. Para-amino hippurate excretion test is an (C) Both (A) and (B) indicator of (D) None of these (A) Glomerular filtration (B) Tubular secretion 319. The number of milliliters of 0.1 N KOH required to neutralize the insoluble fatty (C) Tubular reabsorption acids from 5 gms of fat is called (D) Renal plasma flow (A) Acid number (B) Acetyl number 311. Renal plasma flow of an average adult (C) Halogenation (D) Polenske number man is (A) 120–130 ml/minute 320. The rate of fatty acid oxidation is increased by (B) 325–350 ml/minute (C) 480–52 ml/minute (A) Phospholipids (B) Glycolipids (D) 560–830 ml/minute (C) Aminolipids (D) All of these 312. Filtration fraction can be calculated from 321. Lecithin contains a nitrogenous base named as (A) Standard urea clearance and PSP excretion (B) Maximum urea clearance and PSP excretion (A) Ethanolamine (B) Choline (C) Maximum urea clearance and PAH (C) Inositol (D) All of these clearance 322. Lecithins contain an unsaturated fatty (D) Inulin clearance and PAH clearance acid at position: 313. Normal filtration fraction is about (A) α (B) α and β (A) 0.2 (B) 0.4 (C) β (D) None of these (C) 0.6 (D) 0.8 323. Lecithins are soluble in ordinary solvents 314. Filtration fraction is increased in except (A) Acute glomerulonephritis (A) Benzene (B) Ethyl alcohol (B) Chronic glomerulonephritis (C) Methyl alcohol (D) Acetone (C) Hypertension 324. Lecithins combine with protein to form (D) Hypotension (A) Phosphoprotein (B) Mucoprotein 315. Among the following, a test of Glomeru- (C) Lipoprotein (D) Glycoprotein lar function is 325. Instead of ester link plasmalogens (A) Urea clearance possess an other link in position: (B) PSP excretion test (A) α (B) β (C) PAH clearance (C) γ (D) None of these (D) Hippuric acid excretion test FATS AND FATTY ACID METABOLISM 93

326. The alkyl radical in plasmalogen is an 336. Lipoprotiens may be identified more alcohol: accurately by means of (A) Saturated (B) Unsaturated (A) Electrophoresis (C) Both (A) and (B) (D) None of these (B) Ultra centrifugation 327. The concentration of sphingomyelins are (C) Centrifugation increased in (D) Immunoelectrophoresis (A) Gaucher’s disease 337. Very low density lipoproteins are also (B) Fabry’s disease known as (C) Fabrile disease (A) β-lipoproteins (B) Pre β--lipoproteins (D) Niemann-Pick disease (C) α-lipoproteins (D) None of these 328. Sphingomyelins contain a complex amino alcohol named as 338. The protein moiety of lipoprotein is known as (A) Serine (B) Lysolecithin (C) Sphingosine (D) Glycol (A) Apoprotein (B) Pre-protein (C) Post-protein (D) Pseudoprotein 329. The types of sphingomyelins are 339. The βββ-lipoprotein fraction increases in (A) 1 (B) 3 severe (C) 4 (D) 5 (A) Diabetes Mellitus (B) Uremia 330. Glycolipids contain an amino alcohol: (C) Nephritis (D) Muscular dystrophy (A) Sphingosine (B) Iso-sphingosine 340. ∆∆∆9 indicates a double bond between (C) Both (A) and (B) (D) None of these carbon atoms of the fatty acids: 331. Cerebrosides may also be classified as (A) 8 and 9 (B) 9 and 10 (A) Sphingolipids (B) Sulpholipids (C) 9 and 11 (D) 9 and 12 (C) Aminolipids (D) Glycolipids 341. The number of carbon atoms in decanoic 332. Gaucher’s disease is characterized acid present in butter: specially by the increase in (A) 6 (B) 8 (A) Lignoceric acid (C) 10 (D) 12 (B) Nervonic acid 342. Arachidonic acid contains the number of (C) Cerebomic acid double bonds: (D) Hydroxynervonic acid (A) 2 (B) 3 333. Gangliosides are the glycolipids occurring in (C) 4 (D) 5 (A) Brain (B) Liver 343. The prostaglandins are synthesized from (C) Kidney (D) Muscle (A) Arachidonic acid (B) Oleic acid 334. Lipoprotein present in cell membrane is (C) Linoleic acid (D) Linolenic acid by nature: (A) Hydrophilic (B) Hydrophobic 344. The Iodine number of essential fatty acids (C) Both (A) and (B) (D) None of these of vegetable oils: (A) High (B) Very high 335. The density of lipoproteins increases as the protein content (C) Very low (D) Low (A) Increases 345. Cholesterol is a

(B) Decreases (A) Animal sterol (B) M.F. C27 H46O (C) Highly decreases (C) 5 methyl groups (D) All of these (D) Slightly and promptly decreases 94 MCQs IN BIOCHEMISTRY

346. Waxes contain higher alcohols named as 356. Carboxylation of acetyl —CoA to malonyl (A) Methyl (B) Ethyl — CoA takes place in presence of (C) Phytyl (D) Cetyl (A) FAD+ (B) Biotin (C) NAD+ (D) NADP+ 347. Lieberman-Burchard reaction is performed to detect 357. Malonyl-CoA reacts with the central

(A) Cholesterol (B) Glycerol (A) —SH group (B) —NH2 group

(C) Fatty acid (D) Vitamin D (C) —COOH group (D) —CH2OH group 348. Lipose present in the stomach cannot 358. Fatty acid synthesis takes place in the hydrolyze fats owing to presence of the coenzyme: (A) Alkalinity (B) Acidity (A) NAD+ (B) Reduced NAD (C) High acidity (D) Neutrality (C) NADP+ (D) Reduced NADP 349. Fatty acids are oxidized by 359. Fatty acids are activated to acyl CoA by the enzyme thiokinase: (A) α -oxidation (B) β -oxidation + + (C) ω -oxidation (D) All of these (A) NAD (B) NADP (C) CoA (D) FAD+ 350. The fatty acids containing even number and odd number of carbon atoms as well 360. Phospholipids help the oxidation of as the unsaturated fatty acids are (A) Glycerol (B) Fatty acids oxidized by (C) Glycerophosphates(D) None of these (A) α-oxidation (B) β-oxidation 361. The desaturation and chain elongation (C) ω-oxidation (D) All of these system of polyunsaturated fatty acids are 351. Long chain fatty acids are first activated greatly diminished in the absence of to acyl CoA in the (A) Insulin (B) Glycagon (A) Cytosol (B) Mitochodria (C) Epinephrine (D) Thyroxine (C) Ribosomes (D) Microsome 362. Prostaglandins are liberated in the 352. Long chain acyl CoA penetrates mitochon- circulation by the stimulation of dria in the presence of (A) Anterior pituitary glands (A) Palmitate (B) Carnitine (B) Posterior pituitary glands (C) Sorbitol (D) DNP (C) Adrenal gland 353. Acyl-CoA dehydrogenase converts Acyl (D) Thyroid gland CoA to α- β unsaturated acyl-CoA in 363. Prostaglandins have a common structure presence of the coenzyme: based on prostanoic acid which contains (A) NAD+ (B) NADP+ carbon atoms: (C) ATP (D) FAD (A) 12 (B) 16 354. For the activation of long chain fatty acids (C) 18 (D) 20 the enzyme thiokinase requires the 364. The carbon chains of prostanoic acid are cofactor: bonded at the middle of the chain by a ++ ++ (A) Mg (B) Ca (A) 5-membered ring (B) 6-membered ring ++ + (C) Mn (D) K (C) 8-membered ring (D) None of these 355. ωωω-oxidation takes place by the 365. All active prostaglandins have atleast one hydroxylase in microsomes involving double bond between positions: (A) Cytochrome b (B) Cytochrome c (A) 7 and 8 (B) 9 and 10 (C) Cytochrome p-4500(D) Cytochrome a 3 (C) 11 and 12 (D) 13 and 14 FATS AND FATTY ACID METABOLISM 95

366. The enzyme systems for lengthening and 374. Which of the following is not an unsat- shortening for saturating and desaturat- urated fatty acid? ing of fatty acids occur in (A) Oleic acid (B) Stearic acid (A) Intestine (B) Muscle (C) Linaoleic acid (D) Palmitic acid (C) Kidney (D) Liver 375. All the following are functions of prostag- 367. Which of the following are classified as landins except essential fatty acids? (A) Lowering of B.P (A) Arachidonic acid (B) Oleic acid (B) Introduction of labour (C) Acetic acid (D) Butyric acid (C) Anti inflammatory 368. Prostaglandins are synthesized in the (D) Prevention of myocardial infraction body from 376. Calorific value of lipids per gm is (A) Myristic acid (B) Arachidonic acid (A) 4 Kcal (B) 8 Kcal (C) Stearic acid (D) Lignoceric acid (C) 9 Kcal (D) None of these

369. All the following saturated fatty acids are 377. Fatty acid present in kerotin is present in buffer except (A) Lignoceric acid (B) Cerebromic acid (A) Butyric acid (B) Capryllic acid (C) Nervonic acid (D) Hydroxynervonic acid (C) Caproic acid (D) Capric acid 378. All the following are ketones except 370. Biological functions of lipids include (A) Xylulose (B) Ribolose (A) Source of energy (C) Erythrose (D) Fructose (B) Insulating material 379. Saponification: (C) Maintenance of cellular integrity (A) Hydrolysis of fats by alkali (D) All of these (B) Hydrolysis of glycerol by liposes (C) Esterification 371. Saponification number is (D) Reduction (A) mg of KOH required to saponify one gm of fat or oil 380. Number of ml of 0.1 N KOH required to neutralize fatty acids from 5 gms of fat: (B) mg of KOH required to neutralize free fatty acids of one gms of fat (A) Iodine number (C) mg of KOH required to neutralize the acetic (B) Polenske number acid obtained by saponification of one gm (C) Reichert-Miessl number of fat after it has been acetylated (D) None of these (D) None of these 381. Hydrated density of HD lipoproteins is 372. Lipids have the following properties: (A) 0.94 gm/ml (A) Insoluble in water and soluble in fat solvent (B) 0.94–1.006 gm/ml (C) 1.006–1.063 gm/ml (B) High energy content (D) 1.063–1.21 gm/ml (C) Structural component of cell membrane (D) All of these 382. Saponification number indicates (A) Unsaturation in fat 373. Carbohydrate moiety in cerebrosides is (B) Average M.W of fatty acid (A) Glucose (B) Sucrose (C) Acetyl number (C) Galactose (D) Maltose (D) Acid number 96 MCQs IN BIOCHEMISTRY

383. Acrolein Test is positive for 392. The smell of fat turned rancid is due to (A) Glycerol (B) Prostaglandins (A) Presence of vit E (B) Presence of quinones (C) Carbohydrates (D) Proteins (C) Phenols (D) Volatile fatty acids

384. Iodine number denotes 393. Phospholipids are important cell mem- (A) Degree of unsaturation brane components because (B) Saponification number (A) They have glycerol (C) Acid number (B) They can form bilayers in water (D) Acetyl number (C) They have both polar and non polar potions 385. Maximum energy produced by (D) They combine covalently with proteins (A) Fats (B) Carbohydrates 394. Which one of the following is not a phos- (C) Proteins (D) Nucleic acids pholipid? 386. Lecithins are composed of (A) Lecithin (B) Plasmalogen (A) Glycerol + Fatty acids + Phosphoric acid + (C) Lysolecithin (D) Gangliosides Choline 395. A fatty acid which is not synthesized in (B) Glycerol + Fatty acids + Phosphoric acid + human body and has to be supplied in Ethanolamine the diet: (C) Glycerol + Fatty acids + Phosphoric acid + Serine (A) Palmitic acid (B) Oleic acid (D) Glycerol + Fatty acids + Phosphoric acid + (C) Linoleic acid (D) Stearic acid Beaine 396. In cephalin, choline is replaced by 387. Sphingomyelins are composed of fatty (A) Serine (B) Ethanolamine acids, phosphoric acid and (C) Betaine (D) Sphingosine (A) Sphingosine and choline (B) Glycerol and sphingosine 397. The triacyl glycerol present in plasma lipoproteins are hydrolyzed by (C) Glycerol and Serine (D) Glycerol and Choline (A) Linqual lipase (B) Pancreatic lipase (C) Colipase (D) Lipoprotein lipase 388. Depot fats of mammalian cells comprise mostly of 398. Amphiphatic lipids are (A) Cholesterol (B) Cholesterol esters (A) Hydrophilic (B) Hydrophobic (C) Triacyl glycerol (D) Phospholipids (C) Both (A) and (B) (D) Lipophilic

389. When choline of lecithine is replaced by 399. Which of the following is not essential ethanolamine the product is fatty acid? (A) Sphingomyelin (B) Cephalin (A) Oleic acid (B) Linoleic acid (C) Plasmalogens (D) Lysolecithine (C) Arachidonic acid (D) Linolenic acid 390. Which of the following is a hydroxy fatty 400. The calorific value of lipid is acid? (A) Oleic acid (B) Ricinoleic acid (A) 4.0 Kcal/gm (B) 6.0 Kcal/gm (C) Caproic acid (D) Stearic acid (C) 9.0 Kcal/gm (D) 15 Kcal/gm 391. Acrolein test is answered by 401. Rancidity of butter is prevented by the addition of (A) Cholesterol (B) Glycerol (C) Glycosides (D) Sphingol (A) Vitamin D (B) Tocopherols (C) Presence of priotin (D) Presence of ‘Cu’ FATS AND FATTY ACID METABOLISM 97

402. Sphingomyelins on hydrolysis yields 410. Cholesterol is the precursor for the bio- (A) Glycerol, fatty acids, phosphoric acid and synthesis of choline (A) fatty acid (B) prostaglandins (B) Glycerol, sphingosine, choline and fatty acids (C) bile acids (D) sphingmyelin (C) Sphingosine, phosphoric acid, Glycerol and inositol 411. Which of the following condition is characterized by ketonuria but without (D) Sphingosine, fatty acids, phosphoric acid and glycosuria? choline (A) Diabetes mellitus 403. Inherited deficiency of enzyme cerebro- (B) Diabetes insipidus sidase produces (C) Prolonged starvation (A) Fabry’s disease (D) Addison’s disease (B) Niemann pick disease (C) Gaucher’s disease 412. Ketone bodies are formed in (D) Tay-sach’s disease (A) Kidney (B) Liver 404. Phosphatidic acid on hydrolysis yields (C) Heart (D) Intestines (A) Glycerol, fatty acids, phosphoric acid, choline 413. Changes in serum high density lipoproteins (B) Glycerol, fatty acids, phosphoric acid (HDL) are more truly reflected by those of (C) Glycerol, fatty acids, phosphoric acid, (A) HDL-1 (B) HDL-2

Glucose (C) HDL-3 (D) HDLC (D) Sphingol, fatty acids, phosphoric acid 414. Mitochondrial lipogenesis requires 405. The maximum number of double bonds (A) bicarbonate present in essential fatty acid is (B) biotin (A) 1 (B) 2 (C) acetyl CoA carboxylase (C) 3 (D) 4 (D) NADPH 406. Cerebrosides are composed of 415. Fatty acids having chain length of 10 (A) Sphingosine, fatty acids, glycerol and carbon atoms enter the phosphoric acid (A) Portal ciruclation (B) Lacteals (B) Sphingosine, fatty acids, galactose (C) Systemic circulation (D) Colon (C) Glycerol, fatty acids, galactose (D) Glycerol, fatty acids, galactose, sphingol 416. A soluble system for synthesis of fatty acids have been isolated from avian liver, 407. Acetoacetic acid and βββ-OH butyric acid are required for the formation of long chain formed as fatty acids by this system is (A) Kidneys (B) Heart (A) ATP (B) Acetyl CoA (C) Liver (D) Intestine (C) NADPH (D) All of these 408. Which amino acid is a lipotropic factor? 417. Most animal tissues contain appreciable (A) Lysine (B) Leucine amounts of lipid, when in the form of (C) Tryptophan (D) Methionine depot fat it consists largely of (A) Cholesterol ester (B) Phosphatides 409. The class of lipoproteins having a beneficial effect in atherosclerosis is (C) Chylomicrons (D) Triacylglycerol (A) Low density of lipoproteins 418. A fatty acid not synthesized in man is (B) very low density lipoproteins (A) Oleic (B) Palmitic (C) High density lipoproteins (C) Linoleic (D) Stearic (D) Chylomicrons 98 MCQs IN BIOCHEMISTRY

419. The ‘free fatty acids’ (FFA) of plasma: 425. In the type II (a) hyper lipoproteinemia (A) metabolically inert there is increase in (B) mainly bound to β-lipoproteins (A) Chylomicron bond (B) β (C) stored in the fat (C) Pre beta (D) α (D) mainly bound to serum albumin 426. Normal fat content of liver is about ______420. Adipose tissue which is a store house for gms %. triacyl glycerol synthesis the same using (A) 5 (B) 8 (A) The glycerol released by hydrolysis of triacyl (C) 10 (D) 15 glycerol 427. Obesity is accumulation of ______in the (B) The glycerol-3-phosphate obtained in the body. metabolism of glucose (A) Water (B) NaCl (C) 2-phosphoglycerate (C) Fat (D) Proteins (D) 3-phosphoglycerate 428. The first lipoprotein to be secreted by the 421. Increase in blood of this class of lipopro- liver is teins is beneficial to ward off coronary heart disease: (A) VLDL (B) nascent VLDL (A) HDL (B) LDL (C) LDL (D) IDL (C) VLDL (D) IDL 429. This lipoprotein removes cholesterol from the body 422. In the extra mitochondrial synthesis of (A) HDL (B) VLDL fatty acids, CO2 is utilized (A) To keep the system anaerobic and prevent (C)IDL (D) Chylomicrons regeneration of acetyl CoA 430. When the stired triacylglycerol is lipolysed (B) In the conversion of malonyl to CoA in the adipose tissue blood levels of _____ hydroxybutyryl CoA increased. (C) In the conversion of acetyl CoA to malonyl (A) FFA only CoA (B) Glycerol only (D) In the formation of acetyl CoA from 1 carbon (C) Free fatty acids (FFA) and Glycerol intermediates (D) Triacyl glycero 423. Current concepts concerning the intestinal absorption of triacylglycerols are that 431. All long chain fatty acids with even number of carbon atoms are oxidized to (A) They must be completely hydrolysed before a pool of ______by βββ-oxidation. the constituent fatty acids can be absorbed (A) CO (B) Propionic acid (B) They are hydrolysed partially and the material 2 absorbed consists of free fatty acids, mono (C) Acetic acid (D) Acetyl CoA and diacyl glycerols and unchanged triacyl 432. The level of free fatty acids in plasma is glycerols increased by (C) Fatty acids with less than 10 carbon atoms (A) Insulin (B) Caffeine are absorbed about equally via lymph and via portal blood (C) Glucose (D) Niacin (D) In the absence of bile the hydrolysis of triacyl 433. Cholesterol is excreted as such into glycerols is absorbed ______. 424. Main metabolic end product of cholesterol: (A) Urine (B) Faeces (A) Coprosterol (B) 5-pregnenolone (C) Bile (D)Tears (C) Bile acid (D) Glycine FATS AND FATTY ACID METABOLISM 99

434. LCAT is 442. Cholesterol circulates in blood stream chiefly as (A) Lactose choline alamine transferse (B) Lecithin cholesterol acyl transferase (A) Free cholesterol (C) Lecithin carnitine acyl transferase (B) Ester cholesterol (D) Lanoleate carbamoyl acyl transferase (C) Low density lipoproteins (D) Low density lipoproteins and high density 435. Cholesterol molecule has ______carbon lipoproteins atoms. 443. What is the sub cellular site for the βββ- (A) 27 (B) 21 oxidation of fatty acids? (C) 15 (D) 12 (A) Nucleus (B) Mitochondria 436. A hydrocarbon formed in cholesterol (C) Lysosome (D) Cytosol synthesis is 444. A diet containing this fat is helpful in (A) Mevalonate (B) HMG CoA lowering the blood cholesterol level. (C) Squalene (D) Zymosterol (A) Unsaturated (B) Saturated 437. While citrate is converted to isocitrate in (C) Vitamin enriched (D) Refined the mitochondria, it is converted to ______445. Phospholipase A2 is an enzyme which in the cytosol. removes a fatty acid residue from lecithin (A) Acetyl CoA + oxaloacetate to form (B) Acetyl CoA + malonyl CoA (A) Lecithin fragments (C) Acetyl CoA + Pyruvate (B) Phosphotidic acid (D) Acetyl CoA + acetoacetyl CoA (C) Glyceryl phosphate (D) Lysolecithin 438. Avidin is antigonistic to (A) Niacin (B) PABA 446. Pancreatic lipose is an enzyme which hydrolyzes facts. It acts as a/an (C) Biotin (D) Pantothenic acid (A) peptidase (B) hydrolase 439. CTP is required for the synthesis of (C) carbohydrates (D) dehydrogenase (A) Fatty acids (B) Proteins 447. This interferes with cholesterol absorption (C) Phospholipids (D) Cholesterol (A) Lipoprotein lipase 440. Lysolecithin is formed from lecithin by the (B) action of (C) 7-dehydrocholesterol

(A) Phospholipase A1 (B) Phospholipase A2 (D) β-sitosterol (C) Phospholipase C (D) 448. The carbon chain of fatty acids is shortened 441. Fatty acids can not be converted into by 2 carbon atoms at a time. This involves carbohydrates in the body, as the successive reactions catalysed by 4-enzy- following reaction is not possible: mes. These act the following order: (A) Conversion of glucose-6-phosphate into (A) Acetyl CoA dehydrogenase, β-OH acyl CoA dehydrogenase, enoyl hydrase, thiolose glucose (B) Acyl CoA dehydrogenase, thiolase, enoyl (B) Fructose 1, 6 diphosphate to fructose-6- hydrase, β-OH acyl CoA dehydrogenase phosphate (C) Acyl CoA dehydrogenase, thiolose, enoyl (C) Transformation of acetyl CoA to pyruvate hydrase, β-OH acyl CoA dehydrogenase (D) Formation of acetyl CoA from fatty acids (D) Enoyl hydrase, β-OH acyl CoA dehydroge- nase, acyl CoA dehydrogenase, thiolose, 100 MCQs IN BIOCHEMISTRY

449. Acyl carrier protein is involved in the 457. Very low density lipoproteins are relatively synthesis of rich in (A) protein (A) Cholesterol (B) Triacyl glycerol (B) glycogen (C) Free fatty acids (D) Phospholipids (C) fatty acid outside the mitochondria 458. Neutral fat is stored in (D) fatty acid in the mitochondria (A) Liver (B) Pancreas 450. 1 molecule of palmitic acid on total (C) Adipose tissue (D) Brain oxidation to CO will yield molecules of 2 459. A pathway that requires NADPH as a ATP (as high energy bonds): cofactor is (A) 129 (B) 154 (A) Fatty acid oxidation (C) 83 (D) 25 (B) Extra mitochondrial denovo fatty acid 451. HMG CoA is formed in the metabolism of synthesis (C) Ketone bodies formation (A) Cholesterol, ketones and leucine (D) Glycogenesis (B) Cholesterol, fatty acid and Leucine (C) Lysine, Lecuine and Isoleucine 460. The ‘Committed step’ in the biosynthesis (D) Ketones, Leucine and Lysine of cholesterol from acetyl CoA is (A) Formation of acetoacetyl CoA from acetyl CoA 452. NADPH is produced when this enzyme acts (B) Formation of mevalonate from HMG CoA (A) Pyruvate dehydrogenase (C) Formation of HMG CoA from acetyl CoA and (B) Malic enzyme acetoacetyl CoA (C) Succinate dehydrogenase (D) Formation of squalene by squalene synthetase (D) Malate dehydrogenase 461. In βββ-Oxidation of fatty acids, which of the 453. As a result of each oxidation a long chain following are utilized as coenzymes? fatty acid is cleaved to give (A) NAD+ and NADP+ + (A) An acid with 3-carbon less and propionyl CoA (B) FADH2 and NADH + H (B) An acid with 2-carbon less and acetyl CoA (C) FAD and FMN (C) An acid with 2-carbon less and acetyl CoA (D) FAD and NAD+ (D) An acid with 4-carbon and butyryl CoA 462. The most important source of reducing 454. Liposomes are equivalents for FA synthesis on the liver is (A) Lipid bilayered (B) Water in the middle (A) Glycolysis (C) Carriers of drugs (D) All of these (B) HMP-Shunt 455. Long chain fatty acyl CoA esters are (C) TCA cycle transported across the mitochondrial (D) Uronic acid pathway membrane by 463. All of the following tissue are capable of (A) cAMP (B) Prostaglandin using ketone bodies except (C) Carnitine (D) Choline (A) Brain (B) Renal cortex 456. The acetyl CoA formed on βββ-oxidation of (C) R.B.C. (D) Cardiac muscle all long chain fatty acids is metabolized under normal circumstances to 464. The major source of cholesterol in arterial smooth muscle cells is from (A) CO and water (B) Cholesterol 2 (A) IDL (B) LDL (C) Fatty acids (D) Ketone bodies (C)HDL (D) Chylomicrons FATS AND FATTY ACID METABOLISM 101

465. Ketone bodies are synthesized from fatty 472. In synthesis of Triglyceride from ααα-Glycero acid oxidation products by which of the phosphate and acetyl CoA, the first following organs? intermediate formed is (A) Liver (B) Skeletal muscles (A) β-diacyl glycerol (B) Acyl carnitine (C) Kidney (D) Brain (C) Monoacyl glycerol (D) Phosphatidic acid

466. Chain elongation of fatty acids occurring 473. During each cycle of βββ-oxidation of fatty in mammalian liver takes place in which acid, all the following compounds are of the following subcellular fractions of generated except the cell? (A) NADH (B)H2O (A) Nucleus (B) Ribosomes (C) FAD (D) Acyl CoA (C) Lysosomes (D) Microsomes 474. The energy yield from complete oxidation 467. Which of the following cofactors or their of products generated by second reaction derivatives must be present for the cycle of βββ-oxidation of palmitoyl CoA will conversion of acetyl CoA to malonyl CoA be extramitochondrial fatty acid synthesis? (A) 5 ATP (B) 12 ATP (A) Biotin (B) FAD (C) 17 ATP (D) 34 ATP (C) FMN (D) ACP 475. βββ-Oxidation of odd-carbon fatty acid 468. Which of the following statement regar- ββ chain produces ding βββ-oxidation is true? (A) Requires β-ketoacyl CoA as a substrate (A) Succinyl CoA (B) Propionyl CoA (B) Forms CoA thioesters (C) Acetyl CoA (D) Malonyl CoA (C) Requires GTP for its activity 476. Brown adipose tissue is characterized by (D) Yields acetyl CoA as a product which of the following? 469. All statements regarding 3-OH-3 methyl (A) Present in large quantities in adult humans glutaryl CoA are true except (B) Mitochondrial content higher than white (A) It is formed in the cytoplasm adipose tissue (B) Required in ketogenesis (C) Oxidation and phosphorylation are tightly coupled (C) Involved in synthesis of Fatty acid (D) Absent in hibernating animals (D) An intermediate in cholesterol biosynthesis 477. Ketosis in partly ascribed to 470. Which of the following lipoproteins would contribute to a measurement of (A) Over production and Glucose plasma cholesterol in a normal individual (B) Under production of Glucose following a 12 hr fast? (C) Increased carbohydrate utilization (A) Chylomicrons (D) Increased fat utilization (B) VLDL 478. The free fatty acids in blood are (C) Both VLDL and LDL (D) LDL (A) Stored in fat depots (B) Mainly bound to β-lipoproteins 471. All the following statements regarding (C) Mainly bound to serum albumin ketone bodies are true except (D) Metabolically most inactive (A) They may result from starvation (B) They are formed in kidneys 479. Carnitine is synthesized from (C) They include acetoacetic acid and acetone (A) Lysine (B) Serine (D) They may be excreted in urine (C) Choline (D) Arginine 102 MCQs IN BIOCHEMISTRY

480. A metabolite which is common to path- the correct ordering of these particles from ways of cholesterol biosynthesis from the lowest to the greatest density? acetyl-CoA and cholecalciferol formation (A) LDL, IDL, VLDL, Chylomicron from cholesterol is (B) Chylomicron, VLDL, IDL, LDL (A) Zymosterol (C) VLDL, IDL, LDL, Chylomicron (B) Lumisterol (D) Chylomicron, IDL, VLDL, LDL (C) Ergosterol 488. A compound normally used to conjugate (D) 7 Dehydrocholesterol bile acids is 481. Acetyl CoA required for extra mitochondrial (A) Serine (B) Glycine fatty acid synthesis is produced by (C) Glucoronic acid (D) Fatty acid (A) Pyruvate dehydrogenase complex 489. Which of the following lipoproteins (B) Citrate lyase would contribute to a measurement of (C) Thiolase plasma cholesterol in a normal person (D) Carnitine-acyl transferase following a 12 hr fast? (A) High density lipoprotiens 482. Biosynthesis of Triglyceride and Lecithine both require an intermediate: (B) Low density lipoproteins (C) Chylomicron (A) Monoacyl glycerol phosphate (D) Chylomicron remnants (B) Phosphatidic acid (C) Phosphatidyl ethanol amine 490. Which of the following products of triacylglycerol breakdown and subsequent (D) Phosphatidyl cytidylate βββ-Oxidation may undergo gluconeo- 483. The rage limiting step cholesterol biosyn- genesis? thesis is (A) Acetyl CoA (B) Porpionyl CoA (A) Squalene synthetase (C) All ketone bodies (D) Some amino acids (B) 491. Which of the following regulates lipolysis (C) HMG CoA synthetase in adipocytes? (D) HMG CoA reductase (A) Activation of fatty acid synthesis mediated by 484. All the following are constituents of CAMP ganglioside molecule except (B) Glycerol phosphorylation to prevent futile esterification of fatty acids (A) Glycerol (B) Sialic acid (C) Activation of triglyceride lipase as a result of (C) Hexose sugar (D) Sphingosine hormone stimulated increases in CAMP levels 485. An alcoholic amine residue is present in which of the following lipids? (D) Activation of CAMP production by Insulin (A) Phosphatidic acid (B) Cholesterol 492. Which one of the following compounds is (C) Sphingomyelin (D) Ganglioside a key intermediate in the synthesis of both triacyl glycerols and phospholipids? 486. Sphingosine is the backbone of all the (A) CDP Choline (B) Phosphatidase following except (C) Triacyl glyceride (D) Phosphatidyl serine (A) Cerebroside (B) Ceramide (C) Sphingomyelin (D) Lecithine 493. During each cycle of on going fatty acid oxidation, all the following compounds 487. Chylomicron, intermediate density are generated except lipoproteins (IDL), low density lipoproteins (A) H O (B) Acetyl CoA (LDL) and very low density lipoproteins 2 (C) Fatty acyl CoA (D) NADH (VLDL) all are serum lipoproteins. What is FATS AND FATTY ACID METABOLISM 103

494. All the following statements describing 500. Mitochondrial ααα-ketoglutarate dehydro- lipids are true except genase complex requires all the follow- (A) They usually associate by covalent interactions ing to function except (A) CoA (B) FAD (B) They are structurally components of (C) NAD+ (D) NADP+ membranes 501. Each of the following can be an inter- (C) They are an intracellular energy source mediate in the synthesis of phosphatidyl (D) They are poorly soluble in H2O choline except 495. All the following statements correctly (A) Phosphatidyl inositol describe ketone bodies except (B) CDP-choline (A) They may result from starvation (C) Phosphatidyl ethanolamine (B) They are present at high levels in uncontrolled (D) Diacylglycerol diabetes (C) They include—OH β-butyrate and acetone 502. High iodine value of a lipid indicates (D) They are utilized by the liver during long term (A) Polymerization (B) Carboxyl groups starvation (C) Hydroxyl groups (D) Unsaturation 496. Which of the following features is 503. Cholesterol, bile salts, vitamin D and sex predicted by the Nicolson–Singer fluid hormones are mosaic model of biological membranes? (A) Mucolipids (B) Glycolipids (A) Membrane lipids do not diffuse laterally (C) Phospholipids (D) Isoprenoid lipids (B) Membrane lipid is primarily in a monolayer form 504. Water soluble molecular aggregates of lipids are known as (C) Membrane lipids freely flip-flop (D) Membrane proteins may diffuse laterally (A) Micelle (B) Colloids (C) Sphingol (D) Mucin 497. Oxidative degradation of acetyl CoA in the citric acid cycle gives a net yield of all 505. Hypoglycemia depresses insulin secretion the following except and thus increases the rate of

(A) FADH2 (B) 3 NADH (A) Hydrolysis (B) Reduction

(C) 2 ATP (D) 2CO2 (C) Gluconeogenesis (D) Respiratory acidosis 498. All the following correctly describe the 506. The process of breakdown of glycogen to intermediate 3-OH-3-methyl glutaryl CoA glucose in the liver and pyruvate and except lacate in the muscle is known as (A) It is generated enzymatically in the (A) Glyogenesis (B) Glycogenolysis mitochondrial matrix (C) Gluconeogenesis (D) Cellular degradation (B) It is formed in the cytoplasm 507. Across a membrane phospholipids act as (C) It inhibits the first step in cholesterol synthesis carrier of (D) It is involved in the synthesis of ketone bodies (A) Organic compounds 499. Intermediate in the denovo synthesis of (B) Inorganic ions triacyl glycerols include all the following (C) Nucleic acids except (D) Food materials (A) Fatty acyl CoA (B) CDP diacyl glycerol 508. Osteomalacia can be prevented by the administration of calcium and a vitamin: (C) Glycerol-3-phosphate (D) Lysophosphatidic acid (A) A (B) B (C) C (D)D 104 MCQs IN BIOCHEMISTRY

509. Milk sugar is known as 519. The majority of absorbed fat appears in (A) Fructose (B) Glucose the forms of (C) Sucrose (D) Lactose (A)HDL (B) Chylomicrone (C) VLDL (D)LDL 510. The Instrinisic Factor (HCl and mucopro- teins) present in the gastric juice help in 520. Daily output of urea in grams is the absorption of (A) 10 to 20 (B) 15 to 25 (A) Vitamin B2 (B) Tocopherols (C) 20 to 30 (D) 35 to 45 (C) Folic acid (D) Vitmain B12 521. Uremia occurs in 511. Lipase can act only at pH: (A) Cirrohsis of liver (B) Nephritis (A) 2.5–4 (B) 3.5–5 (C) Diabetes mellitus (D) Coronary thrombosis (C) 4 to 5 (D) 5–7 522. Carboxyhemoglobin is formed by 512. Bile is produced by (A) CO (B) CO2 (A) Liver (B) Gall-bladder (C) HCO (D) HCN (C) Pancreas (D) Intestine 3 523. Methemoglobin is formed as a result of 513. Non-protein part of rhodopsin is the oxidation of haemoglobin by oxida- (A) Retinal (B) Retinol tion agent: (C) Carotene (D) Repsin (A) Oxygen of Air (B) H2O2

514. A pathway that requires NADPH as a co- (C) K4Fe(CN)6 (D) KMnO4 factor is 524. Methemoglobin can be reduced to haemo- (A) Extramitochondrial folic acid synthesis globin by (B) Ketone body formation (A) Removal of hydrogen (C) Glycogenesis (B) Vitamin C (D) Gluconeogenesis (C) Glutathione 515. LCAT activity is associated with which of (D) Creatinine the lipo-? 525. Fats are solids at (A) VLDL (B) Chylomicrones (A) 10°C (B) 20°C (C) IDL (D) HDL (C) 30°C (D) 40°C 516. In β−β−β−oxidation of fatty acids which of the following are utilized as co-enzymes? 526. Esters of fatty acids with higher alcohol other than glycerol are called as (A) NAD+ and NADP+ + (A) Oils (B) Polyesters (B) FAD H2 and NADH + H (C) Waxes (D) Terpenoids (C) FAD and FMN (D) FAD and NAD+ 527. The main physiological buffer in the blood is 517. The lipoprotein with the fastest electro- (A) Haemoglobin buffer phoretic mobility and lowest TG content (B) Acetate are (C) Phosphate (A) VLDL (B) LDL (D) Bicarbonate (C)HDL (D) Chylomicrones 528. All of the following substances have been 518. The essential fatty acids retard used to estimate GFR except (A) Atherosclerosis (B) Diabetes mellitus (A) Inulin (B) Creatinine (C) Nepritis (D) Oedema (C) Phenol red (D) Mannitol FATS AND FATTY ACID METABOLISM 105

529. Relationship between GFR and seum 538. For the activity of amylase which of the creatinine concentration is following is required as co-factor? + (A) Non-existent (B) Inverse (A) HCO3 (B) Na (C) Direct (D) Indirect (C) K+ (D) Cl 530. Urine turbidity may be caused by any of 539. Which of the following hormone the following except increases the absorption of glucose from G.I.T? (A) Phosphates (B) Protein (A) Insulin (B) Throid hormones (C) RBC (D) WBC (C) Glucagon (D) FSH 531. Urine specific gravity of 1.054 indicates 540. Predominant form of storage: (A) Excellent renal function (A) Carbohydrates (B) Fats (B) Inappropriate secretion of ADH (C) Lipids (D) Both (B) and (C) (C) Extreme dehydration (D) Presence of glucose or protein 541. Degradations of Hb takes place in (A) Mitochondrion (B) Erythrocytes 532. In hemolytic jaundice, the urinary bilirubin is (C) Cytosol of cell (D) R.E. cells (A) Normal 542. Biluveridin is converted to bilirubin by the (B) Absent process of (C) More than normal (A) Oxidation (B) Reduction (D) Small amount is present (C) Conjugation (D) Decarboxylation 533. In obstructive jaundice, urinary bilirubin 543. Amylase present in saliva is is (A) α-Amylase (B) β-Amylae (A) Absent (C) γ -Amylase (D) All of these (B) Increased 544. Phospholipids are important cell mem- (C) Present brane components since (D) Present in small amount (A) They have glycerol 534. In hemolytic jaundice, bilirubin in urine is (B) Form bilayers in water (C) Have polar and non-polar portions (A) Usually absent (D) Combine covalently with proteins (B) Usually present (C) Increased very much 545. Which of the following is not a phospho- (D) Very low lipids? (A) Lecithin (B) Plasmalogen 535. The pH of gastric juice of infants is (C) Lysolecithin (D) Gangliosides (A) 2.0 (B) 4.0 546. A fatty acid which is not synthesized in (C) 4.5 (D) 5.0 human body and has to be supplied in 536. The pH of blood is about 7.4 when the the diet is

ratio between (NaHCO3) and (H2CO3) is (A) Palmitic acid (B) Oleic acid (A) 10 : 1 (B) 20 : 1 (C) Linoleic acid (D) Stearic acid (C) 25 : 1 (D) 30 : 1 547. Phospholipids occur in 537. The absorption of glucose is decreased by (A) Myelin sheath the deficiency of (B) Stabilizes chylomicrans (A) Vitamin A (B) Vitamin D (C) Erythrocyte membrane

(C) Thiamine (D) Vitamin B12 (D) All of these 106 MCQs IN BIOCHEMISTRY

548. Which of the following is not essential 553. Spermatozoa in seminal fluid utilises the fatty acids? following sugar for metabolism: (A) Oleic acid (B) Linoleic acid (A) Galactose (B) Glucose (C) Arachidonic acid (D) Linolenic acid (C) Sucrose (D) Fructose 549. The caloric value of lipids is 554. Depot fats of mammalian cells comprise mostly of (A) 6.0 Kcal/g (B) 9.0 Kcal/g (A) Cholesterol (B) Phospholipid (C) 15.0 Kcal/g (D) 12.0 Kcal/g (C) Cerebrosides (D) Triglycerol 550. The maximum number of double bonds 555. When choline of lecithin is replaced by present in essential fatty acid is ethanolamine, the product is (A) 2 (B) 3 (A) Spingomyelin (B) Cephalin (C) 4 (D) 5 (C) Plasmalogens (D) Lysolecithin

551. Prostaglandin synfhesis is increased by 556. Which of the following is a hydroxyl fatty activating phospholipases by acid? (A) Mepacrine (B) Angiotensin II (A) Oleic Acid (B) Ricinoleic acid (C) Glucocorticoids (D) Indomenthacin (C) Caproic acid (D) Arachidonic acid

552. Selwanof’s test is positive in 557. Acroleic test is given by (A) Glucose (B) Fructose (A) Cholesterol (B) Glycerol (C) Galactose (D) Mannose (C) Glycosides (D) Sphingol FATS AND FATTY ACID METABOLISM 107

ANSWERS 1. A 2. A 3. C 4. C 5. D 6. A 7. C 8. D 9. D 10. B 11. D 12. A 13. B 14. A 15. D 16. B 17. B 18. D 19. C 20. D 21. C 22. A 23. D 24. C 25. A 26. A 27. C 28. B 29. B 30. D 31. A 32. A 33. C 34. A 35. A 36. C 37. D 38. A 39. B 40. C 41. D 42. A 43. B 44. C 45. D 46. A 47. D 48. B 49. C 50. C 51. A 52. B 53. D 54. B 55. C 56. D 57. A 58. B 59. D 60. C 61. A 62. A 63. A 64. D 65. B 66. A 67. A 68. B 69. A 70. A 71. A 72. B 73. A 74. D 75. B 76. A 77. B 78. A 79. B 80. C 81. C 82. A 83. A 84. A 85. B 86. B 87. A 88. B 89. D 90. C 91. D 92. B 93. A 94. D 95. B 96. A 97. B 98. D 99. A 100. A 101. C 102. B 103. A 104. B 105. C 106. C 107. B 108. A 109. B 110. C 111. D 112. A 113. A 114. A 115. D 116. A 117. A 118. D 119. C 120. D 121. D 122. A 123. A 124. D 125. B 126. A 127. B 128. A 129. B 130. C 131. B 132. C 133. C 134. B 135. D 136. A 137. C 138. C 139. C 140. B 141. B 142. B 143. C 144. D 145. B 146. D 147. C 148. B 149. A 150. A 151. A 152. A 153. C 154. B 155. D 156. D 157. D 158. D 159. D 160. C 161. B 162. B 163. D 164. C 165. D 166. B 167. D 168. B 169. C 170. A 171. D 172. C 173. A 174. B 175. B 176. C 177. D 178. B 179. B 180. C 181. C 182. B 183. C 184. D 185. D 186. D 187. C 188. B 189. D 190. B 191. C 192. D 193. C 194. C 195. A 196. D 197. B 198. D 199. A 200. C 201. A 202. D 203. C 204. B 205. D 206. A 207. D 208. A 209. C 210. C 211. B 212. A 213. C 214. D 215. D 216. C 217. C 218. D 219. A 220. C 221. D 222. C 223. D 224. D 225. B 226. D 227. D 228. A 229. D 230. B 231. A 232. A 233. D 234. B 235. C 236. C 237. D 238. C 239. B 240. D 241. B 242. D 243. A 244. C 245. C 246. A 108 MCQs IN BIOCHEMISTRY

247. C 248. C 249. A 250. A 251. C 252. A 253. A 254. B 255. C 256. A 257. C 258. A 259. A 260. A 261. B 262. A 263. C 264. A 265. D 266. A 267. D 268. C 269. C 270. C 271. A 272. C 273. C 274. A 275. A 276. A 277. D 278. C 279. A 280. A 281. D 282. C 283. B 284. C 285. A 286. C 287. A 288. C 289. A 290. D 291. C 292. B 293. C 294. B 295. C 296. B 297. B 298. C 299. B 300. A 301. B 302. C 303. B 304. C 305. C 306. A 307. A 308. B 309. D 310. D 311. D 312. A 313. C 314. A 315. D 316. A 317. C 318. B 319. D 320. A 321. B 322. C 323. D 324. C 325. B 326. A 327. B 328. C 329. B 330. C 331. A 332. C 333. A 334. A 335. A 336. D 337. B 338. A 339. A 340. B 341. C 342. C 343. A 344. D 345. D 346. D 347. A 348. C 349. D 350. B 351. A 352. B 353. D 354. B 355. C 356. C 357. A 358. D 359. C 360. B 361. A 362. C 363. D 364. B 365. A 366. D 367. A 368. D 369. C 370. D 371. C 372. D 373. B 374. B 375. D 376. C 377. A 378. C 379. A 380. B 381. D 382. B 383. A 384. A 385. A 386. A 387. A 388. C 389. B 390. B 391. B 392. D 393. C 394. D 395. C 396. B 397. D 398. C 399. A 400. C 401. B 402. D 403. C 404. B 405. D 406. B 407. C 408. D 409. C 410. C 411. C 412. B 413. B 414. D 415. A 416. D 417. D 418. C 419. D 420. B 421. A 422. C 423. B 424. C 425. B 426. A 427. C 428. B 429. A 430. C 431. D 432. B 433. C 434. B 435. A 436. C 437. A 438. C 439. C 440. B 441. C 442. D 443. B 444. A 445. D 446. B 447. D 448. B 449. C 450. A 451. A 452. B 453. B 454. D 455. C 456. A 457. B 458. C 459. B 460. B 461. D 462. B 463. C 464. B 465. A 466. D 467. A 468. A 469. B 470. D 471. B 472. D 473. B 474. D 475. D 476. B 477. D 478. C 479. A 480. D 481. B 482. B 483. D 484. A 485. C 486. D 487. B 488. B 489. A 490. B 491. C 492. B 493. A 494. A 495. D 496. D 497. C 498. C FATS AND FATTY ACID METABOLISM 109

499. B 500. D 501. A 502. D 503. D 504. A 505. C 506. B 507. B 508. D 509. D 510. D 511. D 512. A 513. A 514. A 515. D 516. D 517. C 518. A 519. B 520. C 521. B 522. A 523. C 524. B 525. B 526. C 527. D 528. C 529. B 530. B 531. D 532. C 533. B 534. A 535. D 536. B 537. C 538. D 539. B 540. D 541. D 542. B 543. A 544. C 545. D 546. C 547. D 548. A 549. B 550. C 551. B 552. B 553. D 554. D 555. B 556. B 557. B 110 MCQs IN BIOCHEMISTRY

EXPLANATIONS FOR THE ANSWERS

5. D The fatty acids that cannot be synthesized by 285. A Cyclopentanoperhydrophenanthrene (CPPP), it the body and therefore should be supplied consists of a phenanthrene nucleus to which a through the diet are referred to as essential fatty cyclopentene ring is attached. acids (EFA). Linoleic acid and linolenic acid are 345. D Cholesterol is an animal sterol with a molecular essential. Some workers regard arachidonic formula C H O. it has one hydroxyl group at acid as an EFA although it can be synthesized 27 46 C and a double bond between C and C . An from linoleic acid. 3 5 6 8 carbon aliphatic side chain is attached to 61. A Phrynoderma (toad skin) is an essential fatty acid C , Cholesterol contains of total 5 methyl deficiency disorder. It is characterized by the 17 presence of horny eruptions on the posterior and groups. the lateral parts of the limbs, on the back and 398. C The lipids which possess both hydrophobic and buttocks. hydrophilic groups are known as amphipathic 120. D The hydrolysis of triacylglycerols by alkali to lipids (Greek: amphi- both; pathos- passion). produce glycerol and soaps is known as 454. D Liposomes have an intermittent aqueous phase saponification. in lipid bilayer. They are produced when 173. A Reichert-Meissl number is defined as the number amphipathic lipids in aqueous medium are of moles of 0.1 N KOH required to completely subjected to sonification. Liposomes are used neutralize the soluble volatile fatty acids distilled as carriers of drugs to target tissues. from 5g fat. 540. D Fats (triacyglycerols) are the most predominant 231. A Sphingomyelins (sphingophospholipids) are a storage form of energy, since they are highly group of phospholipids containing sphingosine concentrated form of energy (9 Cal/g) and can as the alcohol (in place of glycerol in other be stored in an anhydrous form (no association phospholipids). with water). VITAMINS 111

CHAPTER 5

VVVITITITAMINSAMINSAMINS

1. Vitamins are 6. Retinol and retinal are interconverted (A) Accessory food factors requiring dehydrogenase or reductase in (B) Generally synthesized in the body the presence of (C) Produced in endocrine glands (A) NAD or NADP (B) NADH + H+ (D) Proteins in nature (C) NADPH (D) FAD 2. Vitamin A or retinal is a 7. Fat soluble vitamins are (A) Steroid (A) Soluble in alcohol (B) Polyisoprenoid compound containing a (B) one or more Propene units cyclohexenyl ring (C) Stored in liver (C) Benzoquinone derivative (D) All these (D) 6-Hydroxychromane 8. The international unit of vitamin A is 3. βββ-Carotene, precursor of vitamin A, is equivalent to the activity caused by oxidatively cleaved by (A) 0.3 µg of Vitamin A alcohol (A) β-Carotene dioxygenase (B) 0.344 µg of Vitamin A alcohol (B) Oxygenase (C) 0.6 µg of Vitamin A alcohol (C) Hydroxylase (D) 1.0 µg of Vitamin A alcohol (D) Transferase 9. Lumirhodopsin is stable only at tempera- 4. Retinal is reduced to retinol in intestinal mucosa by a specific retinaldehyde ture below reductase utilising (A) –10°C (B) –20°C (A) NADPH + H+ (B) FAD (C) –40°C (D) –50°C + (C) NAD (D) NADH + H 10. Retinol is transported in blood bound to 5. Preformed Vitamin A is supplied by (A) Aporetinol binding protein

(A) Milk, fat and liver (B) α2-Globulin (B) All yellow vegetables (C) β-Globulin (C) All yellow fruits (D) Albumin (D) Leafy green vegetables 112 MCQs IN BIOCHEMISTRY

11. The normal serum concentration of 20. Vitamin D absorption is increased in vitamin A in mg/100 ml is (A) Acid pH of intestine (A) 5–10 (B) 15–60 (B) Alkaline pH of intestine (C) 100–150 (D) 0–5 (C) Impaired fat absorption (D) Contents of diet 12. One manifestation of vitamin A deficiency is 21. The most potent Vitamin D metabolite is (A) Painful joints (A) 25-Hydroxycholecalciferol (B) Night blindness (B) 1,25-Dihydroxycholecalciferol (C) Loss of hair (C) 24, 25-Dihydroxycholecalciferol (D) Thickening of long bones (D) 7-Dehydrocholesterol

13. Deficiency of Vitamin A causes 22. The normal serum concentration of 25-hydroxycholecalciferol in ng/ml is (A) Xeropthalmia (B) Hypoprothrombinemia (A) 0–8 (B) 60–100 (C) Megaloblastic anemia (C) 100–150 (D) 8–55 (D) Pernicious anemia 23. The normal serum concentration of 1,25- dihydroxycholecalciferol in pg/ml is 14. An important function of vitamin A is (A) 26–65 (B) 1–5 (A) To act as coenzyme for a few enzymes (C) 5–20 (D) 80–100 (B) To play an integral role in protein synthesis (C) To prevent hemorrhages 24. The normal serum concentration of 24,25- dihydroxycholecalciferol in ng/ml is (D) To maintain the integrity of epithelial tissue

15. Retinal is a component of (A) 8–20 (B) 25–50 (A) Iodopsin (B) Rhodopsin (C) 1–5 (D) 60–100 (C) Cardiolipin (D) Glycoproteins 25. A poor source of Vitamin D is 16. Retinoic acid participates in the synthesis (A) Egg (B) Butter of (C) Milk (D) Liver (A) Iodopsin (B) Rhodopsin 26. Richest source of Vitamin D is (C) Glycoprotein (D) Cardiolipin (A) Fish liver oils (B) Margarine 17. On exposure to light rhodopsin forms (C) Egg yolk (D) Butter (A) All trans-retinal (B) Cis-retinal 27. Deficiency of vitamin D causes (C) Retinol (D) Retinoic acid (A) Ricket and osteomalacia 18. Carr-Price reaction is used to detect (B) Tuberculosis of bone (A) Vitamin A (B) Vitamin D (C) Hypthyroidism (C) Ascorbic acid (D) Vitamin E (D) Skin cancer

19. The structure shown below is of 28. One international unit (I.U) of vitamin D is defined as the biological activity of (A) Cholecalciferol (A) 0.025 µg of cholecalciferol (B) 25-Hydroxycholecalciferol (B) 0.025 µg of 7-dehydrocholecalciferol (C) Ergocalciferol (C) 0.025 µg of ergosterol (D) 7-Dehydrocholesterol (D) 0.025 µg of ergocalciferol VITAMINS 113

29. The βββ-ring of 7-dehydrocholesterol is 38. All the following conditions produce a real cleaved to form cholecalciferol by or functional deficiency of vitamin K except (A) Infrared light (B) Dim light (A) Prolonged oral, broad spectrum antibiotic therapy (C) Ultraviolet irridation with sunlight (B) Total lack of red meat in the diet (D) Light of the tube lights (C) The total lack of green leafy vegetables in 30. Calcitriol synthesis involves the diet (A) Both liver and kidney (D) Being a new born infant (B) Intestine 39. Vitamin K is found in (C) Adipose tissue (A) Green leafy plants (B) Meat (D) Muscle (C) Fish (D) Milk 31. Insignificant amount of Vitamin E is 40. Function of Vitamin A: present in (A) Healing epithelial tissues (A) Wheat germ oil (B) Sunflower seed oil (B) Protein synthesis regulation (C) Safflower seed oil (D) Fish liver oil (C) Cell growth 32. The activity of tocopherols is destroyed (D) All of these by 41. Vitamin K2 was originally isolated from (A) Commercial cooking (A) Soyabean (B) Wheat gram (B) Reduction (C) Alfa Alfa (D) Putrid fish meal (C) Conjugation (D) All of these 42. Vitamin synthesized by bacterial in the intestine is 33. The requirement of vitamin E is increased (A) A (B) C with greater intake of (C) D (D)K (A) Carbohydrates 43. Vitamin K is involved in posttranslational (B) Proteins modification of the blood clotting factors (C) Polyunsaturated fat by acting as cofactor for the enzyme: (D) Saturated fat (A) Carboxylase (B) Decarboxylase 34. Vitamin E reduces the requirement of (C) Hydroxylase (D) Oxidase (A) Iron (B) Zinc 44. Vitamin K is a cofactor for (C) Selenium (D) Magnesium (A) Gamma carboxylation of glutamic acid 35. The most important natural antioxidant residue is (B) β-Oxidation of fatty acid (A) Vitamin D (B) Vitamin E (C) Formation of γ-amino butyrate (D) Synthesis of tryptophan (C) Vitamin B12 (D) Vitamin K 36. Tocopherols prevent the oxidation of 45. Hypervitaminosis K in neonates may cause (A) Vitamin A (B) Vitamin D (A) Porphyria (B) Jaundice (C) Vitamin K (D) Vitamin C (C) Pellagra (D) Prolonged bleeding 37. Creatinuria is caused due to the deficiency 46. Dicoumarol is antagonist to of vitamin (A) Riboflavin (B) Retinol (A) A (B) K (C) Menadione (D) Tocopherol (C) E (D)D 114 MCQs IN BIOCHEMISTRY

47. In the individuals who are given liberal 56. Both Wernicke’s disease and beriberi can quantities of vitamin C, the serum ascorbic be reversed by administrating acid level is (A) Retinol (B) Thiamin (A) 1–1.4 µg/100 ml (C) Pyridoxine (D) Vitamin B12 (B) 2–4 µg/100 ml 57. The Vitamin B deficiency causes (C) 1–10 µg/100 ml 1 (A) Ricket (B) Nyctalopia (D) 10–20 µg/100 ml (C) Beriberi (D) Pellagra 48. The vitamin which would most likely become deficient in an individual who 58. Concentration of pyruvic acid and lactic develop a completely carnivorous life acid in blood is increased due to deficiency style is of the vitamin (A) Thiamin (B) Niacin (A) Thiamin (B) Riboflavin (C) Niacin (D) Pantothenic acid (C) Vitamin C (D) Cobalamin 59. Vitamin B coenzyme (TPP) is involved in 49. In human body highest concentration of 1 ascorbic acid is found in (A) Oxidative decarboxylation (A) Liver (B) Adrenal cortex (B) Hydroxylation (C) Adrenal medulla (D) Spleen (C) Transamination (D) Carboxylation 50. The vitamin required for the formation of hydroxyproline (in collagen) is 60. Increased glucose consumption increases the dietary requirement for (A) Vitamin C (B) Vitamin A (C) Vitamin D (D) Vitamin E (A) Pyridoxine (B) Niacin (C) Biotin (D) Thiamin 51. Vitamin required for the conversion of p- hydroxyphenylpyruvate to homo- 61. Thiamin is oxidized to thiochrome in gentisate is alkaline solution by (A) Folacin (B) Cobalamin (A) Potassium permanganate (C) Ascorbic acid (D) Niacin (B) Potassium ferricyanide (C) Potassium chlorate 52. Vitamin required in conversion of folic (D) Potassium dichromate acid to folinic acid is (A) Biotin (B) Cobalamin 62. Riboflavin is a coenzyme in the reaction catalysed by the enzyme (C) Ascorbic acid (D) Niacin (A) Acyl CoA synthetase 53. Ascorbic acid can reduce (B) Acyl CoA dehydrogenase (A) 2, 6-Dibromobenzene (C) β-Hydroxy acyl CoA (B) 2, 6-Diiodoxypyridine (D) Enoyl CoA dehydrogenase (C) 2, 6-Dichlorophenol indophenol 63. The daily requirement of riboflavin for (D) 2, 4-Dinitrobenzene adult in mg is 54. Sterilised milk lacks in (A) 0–1.0 (B) 1.2–1.7 (A) Vitamin A (B) Vitamin D (C) 2.0–3.5 (D) 4.0–8.0 (C) Vitamin C (D) Thiamin 64. In new born infants phototherapy may 55. Scurvy is caused due to the deficiency of cause hyperbilirubinemia with deficiency of (A) Vitamin A (B) Vitamin D (A) Thiamin (B) Riboflavin (C) Vitamin K (D) Vitamin C (C) Ascorbic acid (D) Pantothenic acid VITAMINS 115

65. Riboflavin deficiency causes 75. Pellagra occurs in population dependent (A) Cheilosis on (B) Loss of weight (A) Wheat (B) Rice (C) Mental deterioration (C) Maize (D) Milk (D) Dermatitis 76. The enzymes with which nicotinamide act 66. Magenta tongue is found in the deficiency as coenzyme are of the vitamin (A) Dehydrogenases (B) (A) Riboflavin (B) Thiamin (C) Decarboxylases (D) Carboxylases (C) Nicotinic acid (D) Pyridoxine 77. Dietary requirement of Vitamin D: 67. Corneal vascularisation is found in defi- (A) 400 I.U. (B) 1000 I.U. ciency of the vitamin: (C) 6000 I.U. (D) 700 I.U. (A) B (B) B 1 2 78. The Vitamin which does not contain a ring (C) B (D) B 3 6 in the structure is 68. The pellagra preventive factor is (A) Pantothenic acid (B) Vitamin D (A) Riboflavin (B) Pantothenic acid (C) Riboflavin (D) Thiamin (C) Niacin (D) Pyridoxine 79. Pantothenic acid is a constituent of the 69. Pellagra is caused due to the deficiency coenzyme involved in of (A) Decarboxylation (B) Dehydrogenation (A) Ascorbic acid (B) Pantothenic acid (C) Acetylation (D) Oxidation (C) Pyridoxine (D) Niacin 80. The precursor of CoA is 70. Niacin or nicotinic acid is a monocarbox- (A) Riboflavin (B) Pyridoxamine ylic acid derivative of (C) Thiamin (D) Pantothenate (A) Pyridine (B) Pyrimidine 81. ‘Burning foot syndrome’ has been (C) Flavin (D) Adenine ascribed to the deficiency of 71. Niacin is synthesized in the body from (A) Pantothenic acid (B) Thiamin (A) Tryptophan (B) Tyrosine (C) Cobalamin (D) Pyridoxine (C) Glutamate (D) Aspartate 82. Pyridoxal phosphate is central to 72. The proteins present in maize are deficient (A) Deamination (B) Amidation in (C) Carboxylation (D) Transamination (A) Lysine (B) Threonine (C) Tryptophan (D) Tyrosine 83. The vitamin required as coenzyme for the action of transaminases is 73. Niacin is present in maize in the form of (A) Niacin (A) Niatin (B) Nicotin (B) Pantothenic acid (C) Niacytin (D) Nicyn (C) Pyridoxal phosphate 74. In the body 1 mg of niacin can be (D) Riboflavin produced from 84. Vitamin B6 deficiency may occur during (A) 60 mg of pyridoxine therapy with (B) 60 mg of tryptophan (A) Isoniazid (B) Terramycin (C) 30 mg of tryptophan (C) Sulpha drugs (D) Aspirin (D) 30 mg of pantothenic acid 116 MCQs IN BIOCHEMISTRY

85. Deficiency of vitamin B6 may occur in 93. The cofactor or its derivative required for the conversion of acetyl CoA to malonyl- (A) Obese person (B) Thin person CoA is (C) Alcoholics (D) Diabetics (A) FAD (B) ACP 86. ‘Xanthurenic acid index’ is a reliable (C) NAD+ (D) Biotin criterion for the deficiency of the vitamin 94. A cofactor required in oxidative decarbox- (A) Pyridoxal (B) Thiamin ylation of pyruvate is (C) Pantothenic acid (D) Cobalamin (A) Lipoate 87. Epileptiform convulsion in human infants (B) Pantothenic acid have been attributed to the deficiency of (C) Biotin the vitamin (D) Para aminobenzoic acid (A) B (B) B 1 2 95. The central structure of B12 referred to as corrin ring system consists of (C) B6 (D) B12 (A) Cobalt (B) Manganese 88. Biotin is a coenzyme of the enzyme (C) Magnesium (D) Iron (A) Carboxylase (B) Hydroxylase (C) Decarboxylase (D) Deaminase 96. The central heavy metal cobalt of vitamin B12 is coordinately bound to 89. The coenzyme required for conversion of (A) Cyanide group (B) Amino group pyruvate to oxaloacetate is (C) Carboxyl group (D) Sulphide group (A) FAD (B) NAD 97. Vitamin B12 has a complex ring structure (C) TPP (D) Biotin (corrin ring) consisting of four 90. In biotin-containing enzymes, the biotin (A) Purine rings (B) Pyrimidine rings is bound to the enzyme by (C) Pyrrole rings (D) Pteridine rings (A) An amide linkage to carboxyl group of 98. Emperical formula of cobalamin is glutamine (A) C63H88N12O14P.CO (B) A covalent bond with CO2 (B) C61H82N12O12P.CO (C) An amide linkage to an amino group of lysine (C) C61H88N12O14P.CO (D) An amide linkage to α-carboxyl group of (D) C63H88N14O14P.CO protein 99. A deficiency of vitamin B12 causes 91. A molecule of CO is captured by biotin 2 (A) Beri-Beri when it acts as coenzyme for carboxyla- (B) Scurvy tion reaction. The carboxyl group is co- (C) Perniciuos anemia valently attached to (D) Ricket (A) A nitrogen (N1) of the biotin molecule 100. Vitamin B deficiency can be diagnosed (B) Sulphur of thiophene ring 12 by urinary excretion of (C) α-Amino group of lysine (A) Pyruvate (B) Methylmalonate (D) α-Amino group of protein (C) Malate (D) Lactate 92. Consumption of raw eggs can cause deficiency of 101. Subacute combined degeneration of cord is caused due to deficiency of (A) Biotin (B) Pantothenic acid (A) Niacin (B) Cobalamin (C) Riboflavin (D) Thiamin (C) Biotin (D) Thiamin VITAMINS 117

102. Vitamin required for metabolism of diols 110. Thiamin deficiency includes e.g. conversion of ethylene glycol to (A) Mental depression (B) Fatigue acetaldehyde is (C) Beriberi (D) All of these (A) Thiamin (B) Cobalamin (C) Pyridoxine (D) Folic acid 111. Thiamin diphosphate is required for oxidative decarboxylation of 103. Both folic acid and methyl cobalamin (A) α-Keto acids (B) α-Amino acids (vitamin B ) are required in 12 (C) Fatty acids (D) All of these (A) Deamination of serine (B) Deamination of threonine 112. Loss of thiamin can be decreased by using (C) Conversion of pyridoxal phosphate to (A) Unpolished rice pyridoxamine phosphate (B) Parboiled rice (D) Methylation of homocystein to methionine (C) Whole wheat flour 104. Folic acid or folate consists of the (D) All of these (A) Base pteridine, p-amino benzoic acid and 113 . Daily requirement of thiamin is asparate (A) 0.1 mg/1,000 Calories (B) Base purine, p-amino benzoic acid and (B) 0.5 mg/1,000 Calories glutamate (C) 0.8 mg/1,000 Calories (C) Base pteridine, p-amino benzoic acid and (D) 1.0 mg/1,000 Calories glutamate (D) Base purine, p-hydroxy benzoic acid and 114. Thiamin requirement is greater in glutamate (A) Non-vegetarians 105. Folate as a coenzyme is involved in the (B) Alcoholics transfer and utilization of (C) Pregnant women (A) Amino group (D) Both B and C (B) Hydroxyl group 115. People consuming polished rice as their (C) Single carbon moiety staple food are prone to (D) Amido group (A) Beriberi (B) Pellagra 106. Folic acid deficiency can be diagnosed by (C) Both (A) and (B) (D) None of these increased urinary excretion of 116. Riboflavin is heat stable in (A) Methylmalonate (B) Figlu (A) Acidic medium (B) Alkaline medium (C) (D) Creatinine (C) Neutral medium (D) Both (A) and (C) 107. Sulpha drugs interfere with bacterial synthesis of 117. FAD is a coenzyme for (A) Lipoate (B) Vitamin E (A) Succinate dehydrogenase (C) Tetrahydrofolate (D) Ascorbic acid (B) Glycerol-3-phosphate dehydrogenase (C) Sphingosine reductase 108. causes (D) All of these (A) Microcytic anemia (B) Hemolytic anemia 118. Riboflavin deficiency can cause (C) Iron deficiency anemia (A) Peripheral neuritis (B) Diarrhoea (D) Megaloblastic anemia (C) Angular stomatitis (D) None of these 109. Thiamin is heat stable in 119. Pellagra preventing factor is (A) Acidic medium (B) Alkaline medium (A) Thiamin (B) Riboflavin (C) Both (A) and (B) (D) None of these (C) Niacin (D) Pyridoxine 118 MCQs IN BIOCHEMISTRY

120. Niacin contains a 130. Sulphydryl group of coenzyme a is contri- (A) Sulphydryl group (B) Carboxyl group buted by (C) Amide group (D) All of these (A) β-Alanine 121. NADP is required as a coenzyme in (B) β-Aminoisobutyric acid (A) Glycolysis (B) Citric acid cycle (C) Methionine (C) HMP shunt (D) Gluconeogenesis (D) Thioethanolamine 122. NAD is required as a coenzyme for 131. Coenzyme A contains a nitrogenous base which is (A) Malate dehydrogenase (B) Succinate dehydrogenase (A) Adenine (B) Guanine (C) Glucose-6-phosphate dehydrogenase (C) Choline (D) Ethanolamine (D) HMG CoA reductae 132. The following is required for the formation 123. NAD is required as a conenzyme in of coenyzme A: (A) Citric acid cycle (A) ATP (B) GTP (B) HMP shunt (C) CTP (D) None of these (C) β-Oxidation of fatty acids 133. Coenzyme A is required for catabolism of (D) Both (A) and (C) (A) Leucine (B) Isoleucine 124. Niacin can be synthesised in human (C) Valine (D) All of these beings from (A) Histidine (B) Phenylalanine 134. Deficiency of pantothenic acid in human (C) Tyrosine (D) Tryptophan beings can affect (A) Nervous system (B) Digestive system 125. Daily requirement of niacin is (C) Both (A) and (B) (D) None of these (A) 5 mg (B) 10 mg (C) 20 mg (D) 30 mg 135. Pyridoxal phosphate is a coenzyme for 126. Niacin deficiency is common in people (A) Glutamate oxaloacetate transaminase whose staple food is (B) Glutamate pyruvate transaminase (A) Wheat (C) Tyrosine transaminase (B) Polished rice (D) All of these (C) Maize and /or sorghum 136. Pyridoxal phosphate is required as a (D) None of these coenzyme in 127. In pellagra, dermatitis usually affects (A) Transamination (B) Transulphuration (A) Exposed parts of body (C) Desulphydration (D) All of these (B) Covered parts of body 137. Pyridoxal phosphate is a coenzyme for (C) Trunk only (D) All parts of the body (A) Glycogen synthetase (B) Phosphorylase 128. Niacin deficiency can occur in (C) Both (A) and (B) (A) Hartnup disease (B) Phenylketonuria (D) None of these (C) Alkaptonuria (D) None of these 138. Pyridoxine deficiency can be diagnosed 129. Pantothenic acid contains an amino acid by measuring urinary excretion of which is (A) Pyruvic acid (B) Oxaloacetic acid (A) Aspartic acid (B) Glutamic acid (C) Xanthurenic acid (D) None of these (C) β-Alanine (D) β-Aminoisobutyric acid VITAMINS 119

139. Pyridoxine deficiency can be diagnosed 147. Folic acid contains by measuring the urinary excretion of (A) Pteridine xanthurenic acid following a test dose of (B) p-Amino benzoic acid (A) Glycine (B) Histidine (C) Glutamic acid (C) Tryptophan (D) Pyridoxine (D) All of these 140. Pyridoxine requirement depends upon 148. Conversion of folate into tetrahydrofolate the intake of requires (A) Carbohydrates (B) Proteins (A) NADH (B) NADPH

(C) Fats (D) None of these (C) FMNH2 (D) FADH2 141. Anti-egg white injury factor is 149. Riboflavin deficiency symptoms are (A) Pyridoxine (B) Biton (A) Glossitis (B) stomatis (C) Thiamin (D) Liponic acid (C) Vomitting (D) Both (A) and (B)

142. When eggs are cooked 150. Vitamin B12 forms coenzymes known as (A) Biotin is destroyed but avidin remains (A) Cobamide (B) Transcobalamin I unaffected (C) Transcobalamin II (D) Both (B) and (C) (B) Avidin is inactivated but biotin remains 151. Methylcobalamin is required for forma- unaffected tion of (C) Both avidin and biotin are inactivated (A) Serin from glycine (D) Both avidin and biotin remain unaffected (B) Glycine from serine 143. Biotin is required as a coenzyme by (C) Methionine from homocysteine (D) All of these (A) Anaerobic dehydrogenases (B) Decarboxylases 152. Absorption of Vitamin B12 requires the presence of (C) Aerobic dehydrogenases (A) Pepsin (B) Hydrochloric acid (D) Carboxylases (C) Intrinsic factor (D) Boh (B) and (C) 144. Biotin is a coenzyme for 153. Intrinsic factor is chemically a (A) Pyruvate carboxylase (A) Protein (B) Acetyl CoA carboxylase (B) Glycoprotein (C) Propionyl CoA carboxylase (C) Mucopolysaccaride (D) All of these (D) Peptide 145. Lipoic acid is a conenzyme for 154. Chemically, Extrinsic Factor of Castle is a (A) Pyruvate dehydrogenase (A) Mucoprotein (B) α-Ketoglutarate dehydrogenae (B) Glycoprotein (C) Both (A) and (B) (C) Mucopolysaccharide (D) None of these (D) Cyanocobalaminm

146. Chemically, lipoic acid is 155. Vitamin B12 is (A) Saturated fatty acid (A) Not stored in the body (B) Unsaturated fatty acid (B) Stored in bone marrow (C) Amino acid (C) Stored in liver (D) Sulphur containing fatty acid (D) Stored in RE cells 120 MCQs IN BIOCHEMISTRY

156. Vitamin B12 is transported in blood by 165. Deficiency of vitamin C causes (A) Albumin (B) Transcortin (A) Beriberi (C) Transcobalamin I (D) Transcobalamin II (B) Pellagra (C) Pernicious anaemia 157. Vitamin B12 is synthesized by (D) Scurvy (A) Bacteria only (B) Plants only (C) Animals only (D) Both (A) and (C) 166. An early diagnosis of vitamin C deficiency can be made by 158. Deficiency of vitamin B can occur because 12 (A) Measuring plasma ascorbic acid of (B) Measuring urinary ascorbic acid (A) Decreased intake of vitamin B 12 (C) Ascorbic acid saturation test (B) Atrophy of gastric mucosa (D) All of these (C) Intestinal malabsorption (D) All of these 167. Daily requirement of vitamin C in adults is about 159. Deficiency of vitamin B can be diagonised 12 (A) 100 mg (B) 25 mg by (C) 70 mg (D) 100 mg (A) Carr-Price reaction (B) Ames assay 168. The vitamin having the highest daily requirement among the following is (C) Watson-Schwartz test (D) Schilling test (A) Thiamin (B) Ribovflavin (C) Pyridoxine (D) Ascorbic acid 160. Gastyrectomy leads to megaloblastic anaemia within a few 169. Anaemia can occur due to the deficiency of all the following except (A) Days (B) Weeks (C) Months (D) Years (A) Thiamin (B) Pyridoxine (C) Folic acid (D) Cyanocobalamin 161. Ascorbic acid is required to synthesise all of the following except 170. A vitamin which can be synthesized by human beings is (A) Collagen (B) Bile acids (C) Bile pigments (D) Epinephrine (A) Thiamin (B) Niacin (C) Folic acid (D) Cyanocobalamin 162. Vitamin C enhances the intestinal

absorption of 171. Laboratory diagnosis of vitamin B12 (A) Potassium (B) Iodine deficiency can be made by measuring the urinary excretion of (C) Iron (D) None of these (A) Xanthurenic acid 163. Vitamin C activity is present in (B) Formiminoglutamic acid (A) D-Ascorbic acid (C) (B) D-Dehydroascorbic acid (D) (C) L-Ascorbic acid 172. The molecule of vitamin A contains (D) Both A and B 1 (A) Benzene ring (B) β-Ionone ring 164. Vitamin C is required for the synthesis of (C) β-Carotene ring (D) None of these (A) Bile acids from cholesterol (B) Bile salts from bile acids 173. Precursor of Vitamin A is (C) Vitamin D from cholesterol (A) α-Carotene (B) β-Carotene (D) All of these (C) γ-Carotene (D) All of these VITAMINS 121

174. Two molecules of vitamin A can be formed 183. is present in from 1 molecule of (A) Retina (B) Liver (A) α-Carotene (B) β-Carotene (C) Both (A) and (B) (D) None of these (C) γ-Carotene (D) All of these 184. Anti-oxidant activity is present in 175. Conversion of βββ-carotene into retinal (A) β-Carotene (B) Retinol requires the presence of (C) Retinoic acid (D) All of these (A) β-Carotene dioxygenase 185. One international Unit of vitamin A is the (B) Bile salts activity present in (C) Molecular oxygen (A) 0.3 µg of β-Carotene (D) All of these (B) 0.3 µg of retinol 176. Conversion of retinal into ritonal requires (C) 0.6 µg of retinoic acid the presence of (D) All of these (A) NADH (B) NADPH 186. Daily requirement of vitamin A in an adult

(C) FADH2 (D) Lipoic acid man can be expressed as 177. Retinal is converted into retinoic acid in (A) 400 IU (B) 1,000 IU the presence of (C) 5,000 IU (D) 10,000 IU (A) (B) Retinal carboxylase 187. Vitamin B6 includes (C) Retinene reductase(D) Spontaneously (A) Pyridoxal (B) Pyridoxamine 178. Vitamin A absorbed in intestine is (C) Pyridoxine (D) All of these released into 188. An early effect of vitamin a deficiency is (A) Portal circulation (B) Lacteals (A) Xerophthalmia (C) Both (A) and (B) (D) None of these (B) Keratomalacia 179. Vitamin A is stored in the body in (C) Prolonged dark adaptation time (D) Follicular hyperkeratosis (A) Liver (B) Adipose tissue 189. Nyctalopia is (C) Reticuloendothelial cells (A) Drying of eyes (D) All of these (B) Destruction of cornea (C) Blindness 180. Rhodopsin contains opsin and (D) Inability to see in dimlight (A) 11-cis-retinal (B) 11-trans-retinal (C) All-cis-retinal (D) All trans-retinal 190. Rod cells possess a trans- which is 181. When light falls on rod cells (A) Adenylate cyclase (B) (A) All-cis-retinal is converted into all-trans-retinal (C) Rhodopsin (D) B as well as C (B) 11-cis-retinal is converted into 11-trans-retinal 191. Provitamins A include (C) 11-trans-retinal is converted into all-trans- retinal (A) Retinal (B) Retionic acid (C) Carotenes (D) All of these (D) 11-cis-retinal is converted into all-trans-retinal 192. Retinoic acid can 182. Conversion of all-trans-retinal into all- trans-retinol requires (A) Act as a photo receptor (A)NAD (B) NADH (B) Support growth and differentiation (C) Act as an anti-oxidant (C) NADP (D) NADPH (D) None of these 122 MCQs IN BIOCHEMISTRY

193. Prosthetic group in cone cell phototrecep- 202. Calcitriol inhibits the conversion of tors is (A) Cholesterol into 7-dehydrocholesterol (A) Iodine (B) Opsin (B) Cholecalciferol into 1-hydroxycholecalciferol (C) 11-cis-retinal (D) all-trans-retinal (C) Cholecalciferol into 25-hydroxycholecalcifer- 194. Retinoic acid is involved in the synthesis ol of (D) 25-Hydroxycholecalciferol into 1,25- dihydrox- (A) Rhodopsin (B) Iodopsin ycholecalciferol (C) Porphyrinopsin (D) Glycoproteins 203. Bowlegs and knock-knees can occur in 195 Transducin is a (A) Rickets (B) Osteomalacia (A) Signal transducer (B) Stimulatory G-protein (C) Both A and B (D) Hypervitaminosis D (C) Trimer (D) All of these 204. Calcification of soft tissues can occur in

196. Provitamin D3 is (A) Osteomalacia (A) Cholecalciferol (B) Rickets (B) Ergosterol (C) Hypervitaminosis D (C) 7-Dehydrocholesterol (D) None of these (D) Ergocaliferol 205. Levels of serum calcium and inorganic 197. Ergosterol is found in phosphorus are increased in (A) Animals (B) Plants (A) Hypervitaminosis D (C) Bacteria (D) All of these (B) Hypoparathyroidism (C) Hypovitaminosis D 198. A provitamin D synthesized in human beings is (D) None of these (A) Ergosterol 206. Requirement of vitamin E increases with (B) 7-Dehydrocholesterol the increasing intake of (C) Cholecalciferol (A) Calories (B) Proteins (D) 25-Hydroxycholecalciferol (C) PUFA (D) Cholesterol

199. 25-Hydroxylation of vitamin D occurs in 207. In human beings, vitamin E prevents (A) Skin (B) Liver (A) Sterility (C) Kidneys (D) Intestinal mucosa (B) Hepatic necrosis 200. Tubular reabsorption of calcium is (C) Muscular dystrophy increased by (D) None of these (A) Cholecalciferol 208. Vitamin E protects (B) 25-Hydroxycholecalciferol (C) Calcitriol (A) Polyunsaturated fatty acids against aperoxidation (D) All of these (B) Vitamin A and carotenes against oxidation 201. Parathormone is required for the conver- (C) Lung tissue against atmospheric pollutants sion of (D) All of these (A) Cholecalciferol into 1-hydroxycholecalciferol (B) Cholecalciferol into 25-hydroxycholecalcifer- 209. Intestinal bacteria can synthesise ol (A) Phyllogquinone (B) Farnoquinone (C) 25-Hydroxycholecalciferol into calcitriol (C) Both (A) and (B) (D) Menadione (D) Cholesterol into 7-dehydrocholesterol VITAMINS 123

210. A water soluble form of vitamin K is 220. The performed Vitamin A is supplied by foods such as (A) Phylloquinone (B) Farnoquinone (C) Menadione (D) None of these (A) Butter (B) Eggs (C) Fish liver oil (D) All of these 211. Prothrombin time is prolonged in 221. The non-protein part of rhodopsin is (A) Vitamin K deficiency (A) Retinal (B) Retinol (B) Liver damage (C) Carotene (D) Repsin (C) Both (A) and (B) (D) None of these 222. Lumirhodopsin is stable only at a temperature below 212. A synthetic form of vitamin K is (A) –35°C (B) –40°C (A) Menadione (B) Farnoquinone (C) –45°C (D) –50°C (C) Phylloquinone (D) None of these 223 The normal concentration of vitamin A in 213. Retinal is reduced to retinol by retinene blood in I.V/dl: reductase in presence of the coenzyme (A) 20–55 (B) 24–60 + + (A) NAD (B) NADP (C) 30–65 (D) 35–70 (C) NADH + H+ (D) NADPH + H+ 224. Continued intake of excessive amounts of 214. Retinal exists as an ester with higher fatty vitamin A especially in children produces acids in the (A) Irritability (B) Anorexia (A) Liver (B) Kidney (C) Headache (D) All of these (C) Lung (D) All of these 225. Vitamin D2 is also said to be 215. Retinol is transported to the blood as (A) Activated ergosterol retinol attached to (B) Fergocalciferol (A) α1-globulin (B) α2-globulin (C) Viosterol (C) β-globulin (D) γ-globulin (D) All of these 216. Carotenes are transported with the 226. The poor sources of vitamin D: (A) Minerals (B) Proteins (A) Eggs (B) Butter (C) Lipids (D) Lipoproteins (C) Milk (D) Liver 217. The drugs that form complexes with 227. The activity of tocopherols is destroyed pyridoxal are by (A) Isoniazid (B) Penicillamine (A) Oxidation (B) Reduction (C) Rifampicin (D) Both (A) and (B) (C) Conjugation (D) All of these 218. In the blood the vitamin esters are 228 Some tocopherols are attached to (A) Terpenoid in structure

(A) α1-lipoproteins (B) α2-lipoproteins (B) Dional in structure (C) β-lipoproteins (D) γ-lipoproteins (C) Isoprenoid in structure 219. The percentage of Vitamin A in the form (D) Farnesyl in structure of esters is stored in the liver: 229. The methyl groups in the aromatic nucleus (A) 80 (B) 85 of a tocopherols are (C) 90 (D) 95 (A) 2 (B) 3 (C) 4 (D) 5 124 MCQs IN BIOCHEMISTRY

230. Vitamin E stored in 240. The number of nutritionally essential (A) Mitochondria (B) Microsomes amino acids for man is (C) Both (A) and (B) (D) None of these (A) 6 (B) 8 (C) 10 (D) 12 231. Vitamin E protects the polyunsaturated fatty acids from oxidation by molecular 241. Avidin is present in oxygen in the formation of (A) Cow’s milk (A) Superoxide (B) Peroxide (B) Raw egg (C) Trioxide (D) All of these (C) Green leafy vegetables 232. The tocopherols prevent the oxidation of (D) Carrots (A) Vitamin A (B) Vitamin D 242. Marasmus is due to malnutrition of (C) Vitamin K (D) Vitamin C (A) Proteins 233. Vitamin E protects enzymes from des- (B) Proteins and calories truction in (C) Proteins and vitamins (A) Muscles (B) Nerves (D) Proteins and minerals (C) Gonads (D) All of these 243. Energy value in kilocalorie per gram of fat in the body is 234. Vitamin K regulates the synthesis of blood clotting factors: (A) 1 (B) 4 (A) VII (B) IX (C) 9 (D) 18 (C) X (D) All of these 244. Which among the following is an essential amino acid for man? 235. Ascorbic acid can reduce (A) Alanine (B) Serine (A) 2, 4-dinitro benzene (C) Valine (D) Glutamic acid (B) 2, 6-Dichlorophenol Indophenol (C) 2, 4-dibromobenzene 245. Under what condition to basal metabolic (D) 2, 6-dibromo benzene rate goes up? (A) Cold environment 236. Sterilized milk is devoid of (B) Hot environment (A) Vitamin A (B) Vitamin B 1 (C) Intake of base forming foods (C) Vitamin C (D) Vitamin D (D) Hypothyroidism 237. The symptoms of scurvy are 246. What is the major form of caloric storage (A) Poor healing of wounds in human body? (B) Loosening of teeth (A) ATP (C) Anaemia (B) Glycogen (D) All of these (C) Creatine phosphate 238. Kwashiorkor results from (D) triacylglycerol (A) Vitamin A deficiency 247. The phosphoprotein of milk is (B) Vitamin D deficiency (A) Lactalbumin (B) Lactoglobulin (C) Deficiency of minerals in diet (C) Vitellin (D) Caein (D) Protein and caloric deficiency in diet 248. Dictary deficiency of this vitamin leads to 239. Which among the following fatty acids is night blindness: an essential fatty acid for man? (A) Retinol (B) Niacin (A) Palmitic acid (B) Oleic acid (C) Ascorbic acid (D) Cholecalciferol (C) Linoleic acid (D) None of these VITAMINS 125

249. A non essential amino acid is not 257. Milk contains very poor amounts of (A) Absorbed in the intestines (A) Calcium (B) Phosphate (B) Required in the diet (C) Iron (D) Riboflavin (C) Incorporated into the protein 258. Egg contains very little (D) Metabolized by the body (A) Fat

250. The deficiency of Vitamin B12 leads to (B) Proteins (A) Pernicious anaemia (C) Carbohydrates (B) Megablastic anaemia (D) Calcium and phosphorus (C) Both (A) and (B) 259. BMR (Basal Metabolic rate) is elevated in (D) None of these (A) Hyper thyroidism (B) Under nutrition 251. Which among the following is a nutrition- (C) Starvation (D) Hypothyroidism ally essential amino acid for man? 260. Soyabean proteins are rich in (A) Alanine (B) Glycine (A) Lysine (B) Alanine (C) Tyrosine (D) Isoleucine (C) Glcyine (D) Aspartic acid 252. The maximum specific dynamic action of 261. Corn and gliadin are low in food stuff is exerted by (A) Lysine (B) Alanine (A) carbohydrates (B) fats (C) Glycine (D) Aspartic acid (C) proteins (D) vitamins 262. What is the disease caused by thiamine 253. The essential amino acids deficiency? (A) must be supplied in the diet because the (A) Nycalopia (B) Scurvy organism has lost the capacity to aminate the (C) Rickets (D) Beriberi corresponding ketoacids 263. Retinol and retinol –binding protein (RBP) (B) must be supplied in the diet because the bound with this protein: human has an impaired ability to synthesize the carbon chain of the corresponding (A) Albumin (B) Prealbumin ketoacids (C) α2-globulin (D) β-globulin (C) are identical in all species studied 264. Megaloblastic anemia is caused by the (D) are defined as these amino acids which deficiency of cannot be synthesized by the organism at a (A) Folic acid (B) Vitamin B rate adequate to meet metabolic requirements 6 (C) Iron (D) Protein 254. Fibre in the diet is beneficial in 265. This vitamin acts as anti-oxidant: (A) Hyper glycemia (A) Vitamin A (B) Vitamin D (B) Hyper cholseteremia (C) Vitamin E (D) Vitamin K (C) Colon cancer 266. Calcitriol is (D) All of these (A) 1-OH-cholecalciferol 255 Sucrose intolerance leads to (B) 25-OH-cholecalciferol (A) Hyper glycemia (B) Glycosuria (C) 24, 25-diOH cholecalciferol (C) Diarrhoea (D) Hypoglycemia (D) 1, 25-diOH cholecalciferol 256. There can be intolerance with respect to 267. 1-hydroxylation of 25-OH vitamin D3 the following sugar: takes place in (A) Glucose (B) Lactose (A) Liver (B) Kidneys (C) Maltose (D) Xylose (C) Intestine (D) Pancreas 126 MCQs IN BIOCHEMISTRY

268. 25-hydroxylation of vitamin D3 takes 279. This abnormal metabolite may be respon- place in sible for the neurological manifestation (A) Liver (B) Kidneys of pernicious anemia: (C) Intestine (D) Pancreas (A) Taurine (B) Methyl malonic acid (C) Xantherunic acid (D) Phenyl pyruvic acid 269. Hydroxylation of 25-hydroxy chole- calciferol is promoted by 280. The vitamin in leafy vegetables: (A) Cytochrome - a (B) Parathyroid hormone (A) D (B) K (C) Cytochrome-b (D) CAMP (C) A (D) Both (B) and (C) 270. The egg injury factor in raw egg white is 281. Isonicotinic acid hydrazide given in the (A) Biotin (B)Avidin treatment of tuberculosis may lead to a deficiency of (C) Albumin (D) Calcium salts (A) Vitamin A (B) Pyridoxin 271. The following has cyanide: (C) Folate (D) Inositol (A) Vitamin B12 282. Biotin is required for the reaction of CO (B) Adenyl cobamide 2 with (C) Benzimidazole cobamide (A) Water (D) Methyl cobamide (B) Acetyl CoA 272. The human species can biosynthesize (C) NH3

(A) Vitamin C (B) Vitamin B12 (D) Incorporation of carbon 6 in purine (C) Thiamine (D) Niacin 283. A deficiency of folate leads to 273. Retina contains this photosensitive (A) Megaloblastic anemia pigment: (B) Aplastic anemia (A) Rhodopsin (B) Opsin (C) Pernicious anemia (C) Retinol (D) Melanin (D) Hypochromic microcytic anemia 274. Anti xerophthalmic vitamin is 284. A deficiency of Iron leads to

(A) Vitamin B1 (B) Vitamin B2 (A) Megaloblastic anemia

(C) Vitamin B6 (D) Vitamin A (B) Aplastic anemia 275. One of the following is not a symptom of (C) Pernicious anemia addison’s disease. (D) Hypochromic microcytic anemia (A) Hypoglycemia (B) Hyponatremia 285. Corninoid coenzymes are coenzymes of (C) Hypokalemia (D) Hypochoremia (A) Vitamin B12 (B) Vitamin B6

276. Gammaxane is an antimetabolite of (C) Vitamin B2 (D) Vitamin B1

(A) Thiamine (B) Riboflavin 286. Vitamin B12 initially binds to the proteins (C) Pyridoxin (D) Inositol known as (A) Transcobalamin I 277. Pyridoxin deficiency may lead to convul- sions as it is needed for the synthesis of (B) R-Proteins (C) Transcobalamin II (A) GABA (B) PABA (D) Intrinsic factor of castle (C) EFA (D) SAM 287. Extrinsic factor of castle is 278. Sulpha drugs are antimetabolities of (A) Vitamin B (B) Glycoprotein (A) Vitamin K (B) Pyridoxin 12 (C) R-Proteins (D) Sigma protein (C) Folic acid (D) Vitamin B2 VITAMINS 127

288. Intrinsic factor of castle is 297. Convulsive episodes occur when there is a severe deficiency of (A) Vitamin B12 (B) Glycoprotein (C) R-Proteins (D) Sigma protein (A) Pyridoxine (B) Folic acid (C) Thiamine (D) Riboflavin 289. Pernicious means 298. Metastatic classification is seen in hyper- (A) Prolonged (B) Dangerous vitaminosis: (C) Intermittent (D) Idiopathic (A) A (B) K 290. Reduction of D-ribonucleotides to D- (C) D (D)E deoxy ribonucleotides in prokaryotes requires 299. The anti vitamin for para aminobenzoic acid is (A) 5, 6 dimethyl benzimidazole cobamide (B) Thioredoxin (A) Aminopterin (B) Dicoumarol (C) Tetra hydrobiopterin (C) Sulphonamides (D) Thiopanic acid (D) Tetra hydrofolate 300. Several pantothenic acid deficiency in man has been reported to cause 291. Biotin is also known as (A) Burning feet syndrome (A) Anti egg white injury factor (B) Scurvy (B) Rutin (C) Cataract (C) Both (A) and (B) (D) Xerophthalmia (D) None of these 301. Cholesterol is a precursor in the biogene- 292. Angular stomatosis is due to sis of (A) Ariboflavinoses (A) Vitamin A (B) Vitamin D (B) Deficiency of Vitamin C (C) Vitamin E (D) None of these (C) Deficiency of Vitamin B1 302. This vitamin is a potent antioxidant of (D) Deficiency of folate vitamin A: 293. One of the main functions of Vitamin K is (A) Vitamin C (B) Vitamin E cofactor for (C) Vitamin K (D) Vitamin D (A) Carboxylate for the formation of γ carboxyglutamate 303. In retinal rickets, the following hydro- xylation of Vitamin D does not take place: (B) Methylation of δ-adenosyl methionine 3 (C) Carboxylation of biotin (A) 25 (B) 1 (C) 24 (D) 7 (D) One carbon transfer by tetrahydrofolate 304. The following does not have phosphorous: 294. Prothrombin time is prolonged by administering (A) Riboflavin (B) TPP + (A) Vitamin K (B) Dicoumarol (C) NAD (D) COASH (C) Calcium (D) Prothrombin 305. Convulsions and delirium could be caused by a severe deficiency of 295. This vitamin acts as antioxidant. (A) Thiamine (B) Glutamate (A) Vitamin A (B) Vitamin D (C) Niacin (D) Magnesium (C) Vitamin E (D) Vitamin K 306. Rice polishings contain this vitamin: 296. This is a photo-labile vitamin. (A) Riboflavin (B) Niacin (A) Thiamine (B) Riboflavin (C) Thiamine (D) Vitamin B (C) Niacin (D) Cholecalciferol 12 128 MCQs IN BIOCHEMISTRY

307. In beri beri there will be accumulation of 316. Taurinuria may be encountered in ______in blood. (A) Permicious anemia (B) Beriberi (A) Aceto acetic acid (B) β-OH butyric acid (C) Pellegra (D) Folate deficiency (C) Pyruvic acid (D) Methyl malonic acid 317. The three vitamins which are specially 308. Symptoms of pellagra are required for proper nerve functions are acid: (A) Dermatitis and diarrhea only (A) Thiamine, niacin and riboflavin (B) Dermatitis and dementia only (B) Thiamine, folic acid, choline (C) Diarrhea, dermatitis and dementia (C) Thiamine, riboflavin, patothenic acid (D) Diarrhea and elements only (D) Thiamine, pyridoxin, vitamin B12 309. Pyridoxine deficiency leads to 318. This is a rich source for vitamin C. (A) Megaloblastic anemia (A) Rice (B) Milk (B) Aplastic anemia (C) Egg (D) Lemon (C) Hypochromic microcytic anemia (D) Permicious anemia 319. The following vitamin is involved in coenzyme function in transaminations: 310. The significant ocular lesion in arbo (A) Nicotinamide (B) Pyridoxine flovinosis: (C) Thiamine (D) Riboflavin (A) Keratomalacia 320. Methyl malonic aciduria is seen in the (B) Bitot’s spots deficiency of (C) Vascularisation of the cornea (A) Vitamin B (B) Folic acid (D) lachrymal metaplasia 6 (C) Thiamine (D) Vitamin B12 311. Irradiation of foods raises the content of 321. Deficiency of Vitamin C leads to (A) Vitamin A (B) Vitamin D (A) Rickets (B) Scurvy (C) Vitamin E (D) Vitamin K (C) Night blindness (D) All of these 312. An anti-vitamin for folic acid is 322. If no primer DNA was given, the following (A) Amethoptesin (B) Dicoumarol scientist could not have synthesized DNA. (C) Pyrithoamine (D) Isoniazid (A) Ochoa (B) Okazaki 313. Thymine is (C) Kornberg (D) Monod (A) Water soluble vitamin 323. Antisterility vitamin is

(B) Fat soluble vitamin (A) Vitamin B1 (B) Vitamin B2 (C) Purine base (C) Vitamin E (D) Vitamin K (D) Pyrimidine base 324. All the following vitamins give rise to 314. The anti-vitamin for para amino benzoic cofactors that are phosphorylated in the acid is active form except (A) Vitamin A (B) Vitamin B (A) Aminopterrin (B) Dicoumarol 1 (C) Vitamin D (D) Vitamin E (C) INH (D) Sulphonamides 325. Molecular Iron, Fe, is 315. The sulphur-containing vitamins among the following B-Vitamin is (A) Stored in the body in combination with Ferritin (A) Thiamine (B) Riboflavin (B) Stored primarily in the spleen (C) Excreted in the urine as Fe2+ (C) Niacin (D) Pyridoxine (D) absorbed in the intestine by albumin VITAMINS 129

326. Humans most easily tolerate a lack of 335. Vitamins that function as dinucleotide which of the following nutrients? derivatives include all the following except (A) Protein (B) Iodine (C) Carbohydrate (D) Lipid (A) Thiamine (B) Niacin (C) Nicotinate (D) Vitamin B2 327. A deficiency of vitamin B12 causes 336. Methyl malonic aciduria is seen in a (A) Cheliosis (B) Beriberi deficiency of (C) Pernicious anemia (D) Scurvy (A) Vitamin B6 (B) Folic acid 328. In adults a severe deficiency of vitamin D (C) Thiamine (D) Vitamin B12 causes 337. What is the disease caused by thiamine (A) Night blindness (B) Osteomalacia deficiency? (C) Rickets (D) Skin cancer (A) Nyctalopia (B) Scurvy 329. Which of the following vitamins would (C) Rickets (D) Beriberi most likely become deficient in a person who develops a completely carnivorous 338. Retinol and Retinol binding protein are life style? bound with this protein: (A) Thiamine (B) Niacin (A) Albumin (B) Prealbumin (C) -globulin (D) -globulin (C) Cobalamine (D) Vitamin C α β 339. Megaloblastic anemia is caused by the 330. Which of the following statements deficiency of regarding Vitamin A is true? (A) Folic acid (B) Vitamin B (A) It is not an essential Vitamin 6 (C) Iron (D) Protein (B) It is related to tocopherol (C) It is a component of rhodopsin 340. This vitamin acts as anti oxidant. (D) It is also known as Opsin (A) Vitamin A (B) Vitamin D 331. Fully activated pyruvate carboxylase (C) Vitamin E (D) Vitamin K depends upon the presence of 341. Calcitriol is (A) Malate and Niacin (A) 1-hydroxy cholecalciferol (B) Acetyl CoA and biotin (B) 25-hydroxy cholecalciferol (C) Acetyl CoA and thiamine pyrophosphate (C) 24, 25-dihydroxy cholecalciferol (D) Oxaloacetate and biotin (D) 1, 25-dihydroxy cholecalciferol 332. Pantothenic acid is a constituent of 342. 1-hydroxylation of 25-hydroxy Vitamin

coenzyme involved in D3 takes place in (A) Acetylation (B) Decarboxylation (A) Liver (B) Kidneys (C) Dehydrogenation (D) Oxidation (C) Intestine (D) Pancreas

333. Biotin is involved in which of the following 343. 25-hydroxylation of Vitamin D3 takes types of reactions? place in (A) Hydroxylation (B) Carboxylation (A) Liver (B) Kidneys (C) Decarboxylation (D) Deamination (C) Intestines (D) Pancreas 334. Which of the following vitamins is the 344. Hydroxylation of 25-hydroxy cholecalcif- precurssor of CoA? erol is promoted by (A) Riboflavin (B) Pantothenate (A) Cytochrome A (B) Panthyroid hormone (C) Thiamine (D) Cobamide (C) Cytochrome b (D) cAMP 130 MCQs IN BIOCHEMISTRY

345. The egg injury factor in raw egg white is 356. Isonicotinic acid hydrazide given in the (A) Biotin (B) Avidin treatment of tuberculosis may lead to a deficiency of (C) Albumin (D) Calcium salts (A) Vitamin A (B) Pyridoxin 346. The following has cyanide: (C) Folate (D) Inositol (A) Vitamin B 12 357. Steroidal prohormone is (B) Adenyl cobamide (A) Vitamin A (B) Vitamin C (C) Benzimidazole cobamide (C) Vitamin D (D) None of these (D) Methyl cobamide 358. A deficiency of folate leads to 347. The human species can biosynthesize (A) Megaloblastic anemia (A) Vitamin C (B) Vitamin B 12 (B) Aplastic anemia (C) Thiamine (D) Niacin (C) Pernicious anemia 348. Retina contains this photo sensitive pigment. (D) Hypochromic microcytic anemia (A) Rhodopsin (B) Opsin 359. Deficiency of Iron leads to (C) Retinol (D) Malanin (A) Megaloblastic anemia 349. Antixerophthalmic vitamin is (B) Aplastic anemia (C) Pernicious anemia (A) Vitamin B1 (B) Vitamin B2 (D) Hypochromic microcytic anemia (C) Vitamin B6 (D) Vitamin A 360. Corrinoid coenzymes are coenzymes of 350. One of the following is not symptom of Addison’s disease: (A) Vitamin B6 (B) Vitamin B12 (C) Vitamin B (D) Vitamin B (A) Hypoglycemia (B) Hyponatremia 2 1

(C) Hypokalemia (D) Hypochloremia 361. Vitamin B12 initially binds to the proteins known as 351. Gammaxine is an antimetabolite of (A) Transcobalamin I (A) Thiamine (B) Riboflavin (B) R-proteins (C) Pyridoxin (D) Inositol (C) Transcobalamin II 352. Pyridoxine deficiency may lead to con- (D) Intrinsic factor of castle vulsions as it is needed for the synthesis 362. Extrinsic factor of castle is of (A) Vitamin B (B) Glycoprotein (A) GABA (B) PABA 12 (C) R-proteins (D) Sigma protein (C) EFA (D) SAM 363. Intrinsic factor of castle is 353. Sulpha drugs are antimetabolites of (A) Vitamin B (B) Glycoprotein (A) PABA (B) Pyridoxin 12 (C) R-proteins (D) Sigma protein (C) Vitamin B2 (D) Pantothenic acid 364. Pernicious means 354. This abnormal metabolite may be respon- (A) Prolonged (B) Dangerous sible for the neurological manifestation of pernicious anemia. (C) Intermittent (D) Idiopathic (A) Taurine (B) Methyl malonic acid 365. Reduction of D-ribonucleotides to D-deoxy (C) Xanthurenic acid (D) Phenyl pyruvic acid ribonucleotides in prokaryotes requires (A) 5, 6 dimethyl benzimindazole cobamide 355. Choline is not required for the formation of (B) Thiredoxin (A) Lecithins (B) Acetyl choline (C) Tetra hydrobiopterin (C) Sphingomyelin (D) Cholic acid (D) Tetra hydrofolate VITAMINS 131

366. Antirachitic vitamin is 376. Cholesterol is a precursor in the biogenesis (A) Vitamin A (B) Vitamin D of (C) Vitamin E (D) Vitamin K (A) Vitamin A (B) Vitamin D (C) Vitamin E (D) None of these 367. Angular stomatitis is due to (A) Ariboflavinosis 377. Which of the vitamins is a potent anti- (B) Deficiency of Vitamin C oxidant of Vitamin A?

(C) Deficiency of Vitamin B1 (A) Vitamin C (B) Vitamin E (D) Deficiency of folate (C) Vitamin K (D) Vitamin D 368. One of the main functions of Vitamin K is 378. In renal rickets, the following hydroxyla-

the cofactor for tion of Vitamin D3 does not take place: (A) Carboxylase for the formation of γ--carboxy (A) 25 (B) 1 glutamate (C) 24 (D) 7 (B) Methylation by S-adenosyl methionine (C) Carboxylation by biotin 379. Which of the following does not have phosphorous? (D) One carbon transfer by tetra hydrofolate (A) Riboflavin (B) TPP 369. Prothrombin time is prolonged by admini- (C) NAD+ (D) CaASH stering (A) Vitamin K (B) Dicoumarol 380. Rice-polishings contain whcih of the (C) Calcium (D) Prothrombin following Vitamin? (A) Riboflavin (B) Niacin 370. This Vitamin acts as antioxidant: (C) Thiamine (D) Vitamin B (A) Vitamin A (B) Vitamin D 12 (C) Vitamin E (D) Vitamin K 381. In beri beri there will be accumulation of ______in blood. 371. This is photo labile vitamin: (A) Aceto acetic acid (A) Thiamine (B) Riboflavin (B) β−hydroxy butyric acid (C) Niacin (D) Cholecalciferol (C) Pyruvic acid 372. Convulsive episodes occur when there is (D) Methyl malonic acid a severe deficiency of: 382. Symptoms of pellagra are (A) Pyridoxine (B) Folic acid (C) Thiamine (D) Riboflavin (A) Dermatitis and diarrhea only (B) Dermatitis and Dermentia only 373. Metastatic calcification is seen in hyper- (C) Diarrhea and dermentia only vitaminosis: (D) Diarrhea, Dermatitis and dementia (A) A (B) K (C) D (D)E 383. Pyridoxine deficiency leads to 374. The anti-vitamin for para amino benzoic (A) Megaloblastic anemia acid is (B) Aplastic anemia (A) Aminopterin (B) Dicoumasol (C) Hypochromic microcytic anemia (C) Sulphanomides (D) Thiopamic acid (D) Pernicious anemia 375. Severe patothemic acid deficiency in man 384. The significant ocular lesion in a ribofla- has been reported to cause vinosis is (A) Burning feet syndrome (A) Keratomalacia (B) Scurvy (B) Bitot’s spots (C) Cataract (C) Vascularisation of the cornea (D) Xeropththalmia (D) Lachrynal metaplasia 132 MCQs IN BIOCHEMISTRY

385. An anti-vitamin for folic acid is 395. Anti sterility Vitamin is

(A) Aminopterin (B) Dicoumarol (A) Vitamin B1 (B) Vitamin B2 (C) Pyrithiamine (D) Isoniazid (C) Vitamin E (D) Vitamin K 386. Thiamine is 396. Biotin deficiency is characterized by the (A) Water-soluble vitamin following except (B) Fat soluble vitamin (A) Muscular pain (B) Anaemia (C) Purine base (C) Nausea (D) Dermatitis (D) Pyrimidine base 397. Deficiency of thiamine causes 387. The anti-vitamin for para amino benzoic (A) Beri beri (B) Scurvy acid is (C) Night blindness (D) Rickets (A) Aminopterin (B) Dicoumarol 398. Deficiency of Vitamin D leads to (C) INH (D) Sulphanomides (A) Rickets (B) Osteomalacia 388. The sulphur containing vitamins among (C) Xeropthalmia (D) Both (A) and (B) the following B Vitamin is 399. The vitamin that is useful in cancer is (A) Thiamine (B) Riboflavin (A)A (B) B complex (C) Niacin (D) Pyridoxine (C) C (D)E 389. Taurinuria may be encountered in 400. Vitamin A over dosage causes injury to (A) Pernicious anemia (B) Beriberi (A) Mitochondria (B) Microtubules (C) Pellegra (D) Folate deficiency (C) Lysosomes (D) E.R 390. The three vitamins which are specially 401. Which is a pro vitamin or vitamin that has required for proper nerve functions are antioxidant properties? (A) Thiamine, Niacin and Riboflavin (A) Beta carotene (B) Vitamin E (B) Thiamin, Folic acid, Choline (C) Vitamin C (D) Vitamin D (C) Thiamine, Riboflavin, Pantothenic acid (D) Thiamine, Pyridoxin, Vitamin B 402. The vitamin required for carboxylation 12 reaction is 391. This is a rich source for Vitamin C: (A) Vitamin B2 (B) Vitamin B6 (A) Rice (B) Milk (C) Biotin (D) Vitamin B12 (C) Egg (D) Lemon 403. Biological activity of tocopherols has been 392. Which ot the following vitamin is involved attributed in part to their action as in coenzyme function in transaminations? (A) Antioxidant (A) Nicotinamide (B) Pyridoxine (B) Anticoagulents (C) Thiamine (D) Riboflavin (C) Provitamin 393. Methyl malonic aciduria is seen in a (D) Carriers in electron transport system deficiency of 404. Biotin is essential for

(A) Vitamin B6 (B) Folic acid (A) Translation (B) Carboxylation

(C) Thiamine (D) Vitamin B12 (C) Hydroxylation (D) Transamination 394. In pernicious anemia, Urine contains high 405. Which of the following vitamin act as a amounts of respiratory catalyst?

(A) Methyl malonic acid (B) FIGLU (A) B2 (B) Pyridoxine

(C) VMA (D) 5 HIAA (C) B12 (D) C VITAMINS 133

406. Metal in Vitamin B12 is 416. During deficiency of thiamine the concen- (A) Copper (B) Cobalt tration of the following compound rises in blood and intracellular fluid: (C) Iron (D) Zinc (A) Glycogen (B) Sugar 407. Whole wheat is an excellent source of (C) Amino acids (D) Pyruvic acid (A) Vitamin D (B) Vitamin C 417. The conversion of carotenoids to Vitamin (C) Vitamin A (D) Thiamine A takes place in 408. Vitamin used in the treatment of homo- (A) Intestine (B) Liver cystinuria is (C) Kidney (D) Skin (A) B (B) B 1 5 418. Man cannot synthesize vitamin: (C) B12 (D) B6 (A) A (B) B 409. Which of the following is not a component (C) C (D)D of coenzyme A? 419. Vitamin A is required for the formation (A) Pantothenic acid (B) Adenylic acid of a light receptor protein known as (C) Acetic acid (D) Sulfhydryl group (A) Globulin (B) Lypoprotein 410. The most active form of Vitamin D is (C) Chomoprotein (D) Rhodospin (A) 25-Hydroxycholecalciferol 420. Excessive vitamin A in children produces (B) 1, 25-dihydroxycholecalciferol (A) Irritability (B) Anorexia (C) 25-dihydroxyergocalciferol (C) Headache (D) All of these (D) None of these 421. Tocopherols prevent the oxidation of 411. The important part in the structure of flavoprotein is (A) Vitamin A (B) Vitamin D (C) Vitamin K (D) Vitamin C (A) Vitamin B6 (B) Vitamin B2 422. Vitamin K regulates the synthesis of blood (C) Vitamin B1 (D) Vitamin A clotting factors. 412. Vitamin essential for transamination is (A) VII (B) IX (A) B (B) B 1 2 (C) X (D) All of these (C) B (D) B 6 12 423. The colour of cyanomethmoglobin is 413. The action of Vitamin K in formation of (A) Pale yellow (B) Pink clotting factor is through (C) Brown (D) Bright red (A) Post transcription 424. Transketolase activity is affected in (B) Post translation (C) Golgi complex (A) Bitoin deficiency (B) Pyridoxine deficiency (D) Endoplasmic reticulum (C) PABA deficiency 414. Vitamin necessary for CoA synthesis: (D) Thiamine deficiency (A) Pantothenic acid (B) Vitamin C 425. The hydrolysis of glucose-6-PO4 is cata- (C) B6 (D) B12 lyzed by a phosphatase that is not found 415. Cofactor for transamination is in which of the following? (A) Liver (B) Kidney (A) Thymine (B) Riboflavin (C) Muscle (D) Small intestine (C) Pyridoxine (D) Niacin 134 MCQs IN BIOCHEMISTRY

426. Vitamin K2 was originally isolated from (A) Thiamine (B) Riboflavine (A) Soyabean (B) Putrid fishmeal (C) Folic acid (D) Nicotininic acid (C) Alfa alfa (D) Oysters 430. The deficiency of which one of the 427. The following form of vitamin A is used following vitamin causes creatinuria? in the visual cycle: (A) Vitamin E (B) Vitamin K

(A) Retinol (B) Retinoic acid (C) Vitamin A (D) Vitamin B6 (C) Retinaldehyde (D) Retinyl acetate 431. A biochemical indication of vitamin B12 428. Increased carbohydrate consumption deficiency can be obtained by measuring increases the dietary requirement for the urinary excretion of (A) Thiamine (B) Riboflavine (A) Pyruvic acid (C) Pyridoxine (D) Folic acid (B) Malic acid (C) Methyl malonic acid 429. Increased protein intake is accompanied (D) by an increased dietary requirement for VITAMINS 135

ANSWERS 1. A 2. B 3. A 4. A 5. A 6. A 7. D 8. A 9. D 10. A 11. B 12. B 13. A 14. D 15. B 16. C 17. A 18. A 19. A 20. A 21. B 22. D 23. A 24. C 25. C 26. A 27. A 28. A 29. C 30. A 31. D 32. A 33. C 34. C 35. B 36. A 37. C 38. B 39. A 40. D 41. D 42. D 43. A 44. A 45. B 46. C 47. A 48. C 49. B 50. A 51. D 52. C 53. C 54. C 55. D 56. B 57. C 58. A 59. A 60. D 61. B 62. B 63. B 64. B 65. A 66.A 67. B 68. C 69. D 70. A 71. A 72. C 73. C 74. B 75. C 76. A 77. A 78. A 79. C 80. D 81. A 82. D 83. C 84. A 85. C 86. A 87. C 88. A 89. D 90. C 91. A 92. A 93. D 94. A 95. A 96. A 97. C 98. D 99. C 100. B 101. B 102. B 103. D 104. C 105. C 106. B 107. C 108. D 109. A 110. D 111. A 112. D 113. B 114. D 115. A 116. D 117. D 118. C 119. C 120. B 121. C 122. A 123. D 124. D 125. C 126. C 127. A 128. A 129. C 130. D 131. A 132. A 133. D 134. C 135. D 136. D 137. B 138. C 139. C 140. B 141. B 142. B 143. D 144. D 145. C 146. D 147. D 148. B 149. D 150. A 151. C 152. D 153. B 154. D 155. C 156. D 157. A 158. D 159. D 160. D 161. C 162. C 163. C 164. A 165. D 166. C 167. C 168. D 169. A 170. B 171. C 172. B 173. D 174. B 175. D 176. B 177. D 178. B 179. A 180. A 181. D 182. D 183. B 184. A 185. B 186. C 187. D 188. C 189. D 190. C 191. C 192. B 193. C 194. D 195. D 196. C 197. B 198. B 199. B 200. C 201. C 202. D 203. A 204. C 205. A 206. C 207. D 208. D 209. B 210. C 211. C 212. A 213. C 214. D 215. A 216. D 217. D 218. C 219. D 220. D 221. A 222. D 223. B 224. D 225. D 226. C 227. A 228. A 229. B 230. C 231. B 232. A 233. D 234. D 235. B 236. C 237. B 238. D 239. C 240. B 241. B 242. B 243. C 244. C 245. A 246. C 136 MCQs IN BIOCHEMISTRY

247. D 248. A 249. B 250. C 251. D 252. C 253. B 254. D 255. C 256. B 257. C 258. C 259. A 260. B 261. D 262. D 263. B 264. A 265. C 266. D 267. B 268. A 269. B 270. B 271. A 272. D 273. A 274. D 275. C 276. D 277. A 278. C 279. A 280. D 281. D 282. B 283. B 284. A 285. D 286. B 287. B 288. A 289. B 290. B 291. A 292. B 293. A 294. A 295. B 296. C 297. B 298. A 299. C 300. C 301. A 302. B 303. B 304. A 305. D 306. D 307. C 308. C 309. C 310. B 311. C 312. A 313. D 314. D 315. A 316. A 317. D 318. D 319. B 320. D 321. C 322. C 323. C 324. B 325. A 326. C 327. C 328. B 329. D 330. C 331. B 332. A 333. B 334. B 335. A 336. D 337. D 338. B 339. A 340. D 341. D 342. B 343. A 344. B 345. B 346. A 347. D 348. A 349. D 350. C 351. D 352. A 353. A 354. B 355. D 356. B 357. C 358. A 359. D 360. B 361. B 362. A 363. B 364. B 365. A 366. B 367. A 368. A 369. B 370. C 371. B 372. A 373.C 374. C 375. A 376. B 377. B 378. B 379. A 380. C 381. C 382. D 383. C 384. C 385. A 386. D 387. D 388. A 389. A 390. D 391. D 392. B 393. D 394. A 395. C 396. B 397. A 398. D 399. A 400. C 401. B 402. C 403. B 404. B 405. A 406. B 407. D 408. D 409. C 410. A 411. B 412. C 413. B 414. A 415. C 416. D 417. A 418. C 419. D 420. D 421. A 422. D 423. D 424. D 425. C 426. B 427. C 428. A 429. A 430. C 431. C VITAMINS 137

EXPLANATIONS FOR THE ANSWERS 250. C The liver can store up to six years worth of vitamin B , hence deficiencies in this vitamin are rare. 7. D The four fat soluble vitamins (A, D, E, K) are 12 Penicious anemia is a megaloblastic anemia soluble in fats, oils and fat solvents (alcohol, resulting from vitamin B deficiency that develops acetone etc.). Their occurrence in the diet, 12 as a result a lack of intrinsic factor in the stomach absorption and transport are associated with fat. leading to malabsorption of the vitamin. All the fat soluble vitamins contain one or more 291. A Biotin is also called anti-egg white injury factor of isoprene units (5 carbon units). They can be because, egg white contains a protein called stored in liver and adipose tissue. avidin, which combines with biotin in the 40. D Vitamin A is essential to maintain healthy intestinal tract and prevents absorption of biotin epithelial tissues and proper immunity. Retinol from intestines. and retinoic acid functions like steroid hormones. 321. B Deficiency in Vitamin C leads to the disease They regulate protein synthesis and thus are scurvy due to the role of the vitamin in the post- involved in cell growth and differentiation. β- translational modification of . Scurvy is Carotene functions as an antioxidant and reduces characterized by easily bruised skin, muscle the risk for heart attack, cancers etc. fatigue, soft swollen gums, decreased wound 77. A The recommended dietary allowances for vitamin healing and hemorraging, osteoporosis and D is around 400 I.U. In countries with good anemia. sunlight (like India), it is much lower. i.e., 200 357. C Vitamin D is a steroid prohormone. It is I.U. The good sources include fatty fish, fish liver represented by steroids that occur in animals, oils, egg yolk. plants and yeast. Active form of the hormone is 110. D The earliest symptoms of thiamin deficiency include 1, 25-dihydroxy vitamin D (1, 25-(OH) D , also constipation, appetite suppression, nausea as well 3 2 3 termed calcitriol). Calcitriol functions primarily as mental depression, peripheral neuropathy and to regulate calcium and phosphorous fatigue. Chronic thiamin deficiency leads to more homeostasis. severe neurological symptoms including ataxia, 398. D The main symptom of vitamin D deficiency in mental confusion and loss of eye coordination. children is rickets and in adults is osteomalacia. Other clinical symptoms of prolonged thiamin Rickets is characterized by improper deficiency are related to cardiovascular and mineralization during the development of the muscular defects. The severe thiamin deficiency bones resulting in soft bones. Osteomalacia is disease is known as Beriberi. characterized by demineralization of previously 149. D Riboflavin deficiency is often seen in chronic formed bone leading to increased softness and alcoholics due to their poor diabetic habits. susceptibility to fracture. Symptoms associated with riboflavin deficiency include, glossitis, seborrhea, angular stomatitis, cheilosis and photophobia. Riboflavin decomposes when exposed to visible light. 187. D Pyridoxal, pyridoxamine and pyridoxine are

collectively known as vitamin B6. All three compounds are efficiently converted to the

biologically active form of vitamin B6, pyridoxal phosphate. This conversion is catalyzed by the ATP requiring enzyme, . 217. D Isoniazid (anti-tuberculosis drug) and penicillamine (used to treat rheumatoid arthritis and cystinurias) are two drugs that complex with pyridoxal and pyridoxal phosphate resulting in a deficiency in this vitamin. This page intentionally left blank CHAPTER 6

EEENZYMESNZYMESNZYMES

1. The compound which has the lowest 7. Krabbe’s disease is due to the deficiency density is of the enzyme: (A) Chylomicron (B) β-Lipoprotein (A) Ceramide lactosidase (C) α-Lipoprotein (D) pre β-Lipoprotein (B) Ceramidase 2. Non steroidal anti inflammatory drugs, (C) β-Galactosidase such as aspirin act by inhibiting the activity of the enzyme: (D) GM1 β-Galactosidase (A) Lipoxygenase (B) Cyclooxygenase 8. Fabry’s disease is due to the deficiency of

(C) Phospholipase A2 (D) Lipoprotein lipase the enzyme: 3. From arachidonate, synthesis of prostag- (A) Ceramide trihexosidase landins is catalysed by (B) Galactocerebrosidase (A) Cyclooxygenase (C) Phytanic acid oxidase (B) Lipoxygenase (D) Sphingomyelinase (C) Thromboxane synthase (D) Isomerase 9. Farber’s disease is due to the deficiency 4. A Holoenzyme is of the enzyme: (A) Functional unit (B) Apo enzyme (A) α-Galactosidase (C) Coenzyme (D) All of these (B) Ceramidase 5. Gaucher’s disease is due to the deficiency (C) β-Glucocerebrosidase of the enzyme: (D) Arylsulphatase A. (A) α-Fucosidase (B) β-Galactosidase 10. A synthetic nucleotide analogue, used in (C) β-Glucosidase (D) Sphingomyelinase organ transplantation as a suppressor of 6. Neimann-Pick disease is due to the defi- immunologic rejection of grafts is ciency of the enzyme: (A) Theophylline (A) Hexosaminidase A and B (B) Cytarabine (B) Ceramidase (C) 4-Hydroxypyrazolopyrimidine (C) Ceramide lactosidase (D) Sphingomyelinase (D) 6-Mercaptopurine 140 MCQs IN BIOCHEMISTRY

11. Example of an extracellular enzyme is 18. From the Lineweaver-Burk plot of (A) Michaelis-Menten equation, Km and Vmax can be determined when V is the (B) Cytochrome oxidase reaction velocity at substrate concentra- (C) Pancreatic lipase tion S, the X-axis experimental data are (D) Hexokinase expressed as 12. Enzymes, which are produced in inactive (A) 1/V (B) V form in the living cells, are called (C) 1/S (D) S

(A) Papain (B) 19. A sigmoidal plot of substrate concentra- (C) Apoenzymes (D) Proenzymes tion ([S]) verses reaction velocity (V) may 13. An example of is indicate (A) Succinate thiokinase (A) Michaelis-Menten kinetics (B) (B) Co-operative binding (C) Fumarase (C) Competitive inhibition (D) Aldolase (D) Non-competitive inhibition

14 An example of is 20. The Km of the enzyme giving the kinetic data as below is (A) (A) –0.50 (B) –0.25 (B) Fumarase (C) +0.25 (D) +0.33 (C) Cholinesterase (D) Amylase 21. The kinetic effect of purely competitive inhibitor of an enzyme 15. Activation or inactivation of certain key regulatory enzymes is accomplished by (A) Increases Km without affecting Vmax

covalent modification of the amino acid: (B) Decreases Km without affecting Vmax

(A) Tyrosine (B) Phenylalanine (C) Increases Vmax without affecting Km

(C) Lysine (D) Serine (D) Decreases Vmax without affecting Km

16. The enzyme which can add water to a 22. If curve X in the graph (below) represents carbon-carbon double bond or remove no inhibition for the reaction of the water to create a double bond without enzyme with its substrates, the curve breaking the bond is representing the competitive inhibition, of the same reaction is (A) Hydratase (B) Hydroxylase (C) Hydrolase (D) (A) A (B) B (C) C (D)D 17. Fischer’s ‘lock and key’ model of the enzyme action implies that 23. An inducer is absent in the type of enzyme: (A) The active site is complementary in shape to (A) Allosteric enzyme that of substance only after interaction. (B) Constitutive enzyme (B) The active site is complementary in shape to (C) Co-operative enzyme that of substance (D) Isoenzymic enzyme (C) Substrates change conformation prior to active site interaction 24. A demonstrable inducer is absent in (D) The active site is flexible and adjusts to (A) Allosteric enzyme (B) Constitutive enzyme substrate (C) Inhibited enzyme (D) Co-operative enzyme ENZYMES 141

25. In reversible non-competitive enzyme 32. An enzyme catalyzing oxidoreduction, activity inhibition using oxygen as hydrogen acceptor is

(A) Vmax is increased (A) Cytochrome oxidase

(B) Km is increased (B) Lactate dehydrogenase

(C) Km is decreased (C) Malate dehydrogenase (D) Concentration of active enzyme is reduced (D) Succinate dehydrogenase 26. In reversible non-competitive enzyme 33. The enzyme using some other substance, activity inhibition not oxygen as hydrogen acceptor is (A) Inhibitor bears structural resemblance to (A) Tyrosinase substrate (B) Succinate dehydrogenase (B) Inhibitor lowers the maximum velocity (C) Uricase attainable with a given amount of enzyme (D) Cytochrome oxidase (C) Km is increased 34. An enzyme which uses hydrogen acceptor (D) K is decreased m as substrate is 27. In competitive enzyme activity inhibition (A) Xanthine oxidase (A) The structure of inhibitor generally resembles (B) that of the substrate (C) Catalase (B) Inhibitor decreases apparent Km (D) Tryptophan oxygenase (C) Km remains unaffective 35. Enzyme involved in joining together two (E) Inhibitor decreases V without affecting K max m substrates is 28. In V reflects max (A) Glutamine synthetase (A) The amount of an active enzyme (B) Aldolase (B) Substrate concentration (C) Gunaine deaminase (C) Half the substrate concentration (D) Arginase (D) Enzyme substrate complex 36. The pH optima of most of the enzymes is 29. In enzyme kinetics Km implies (A) Between 2 and 4 (B) Between 5 and 9 (A) The substrate concentration that gives one half (C) Between 8 and 12(D) Above 12 Vmax 37. Coenzymes are (B) The dissocation constant for the enzyme substrate comples (A) Heat stable, dialyzable, non protein organic (C) Concentration of enzyme molecules (D) Half of the substrate concentration required (B) Soluble, colloidal, protein molecules

to achieve Vmax (C) Structural analogue of enzymes (D) Different forms of enzymes 30. In competitive enzyme activity inhibition 38. An example of hydrogen transferring (A) Apparent Km is decreased coenzyme is (B) Apparent Km is increased (A) CoA (B) NAD+ (C) Vmax is increased (C) Biotin (D)TPP (D) Vmax is decreased 31. In non competitive enzyme activity inhi- 39. An example of group transferring bition, inhibitor coenzyme is (A) NAD+ (B) NADP+ (A) Increases Km (B) Decreases Km (C) FAD (D) CoA (C) Does not effect Km (D) Increases Km 142 MCQs IN BIOCHEMISTRY

40. Cocarboxylase is 48. The normal serum GOT activity ranges from (A) Thiamine pyrophosphate (B) Pyridoxal phosphate (A) 3.0–15.0 IU/L (B) 4.0–17.0 IU/L (C) Biotin (C) 4.0–60.0 IU/L (D) 0.9–4.0 IU/L (D) CoA 49. The normal GPT activity ranges from 41. A coenzyme containing non aromatic (A) 60.0–250.0 IU/L (B) 4.0–17.0 IU/L hetero ring is (C) 3.0–15.0 IU/L (D) 0.1–14.0 IU/L (A) ATP (B) NAD 50. The normal serum (C) FMN (D) Biotin activity ranges from 42. A coenzyme containing aromatic hetero (A) 5.0–13.0 KA units/100 ml ring is (B) 1.0–5.0 KA units/100 ml (C) 13.0–18.0 KA units/100 ml (A) TPP (B) Lipoic acid (D) 0.2–0.8 KA units/100 ml (C) Coenzyme Q (D) Biotin 51. The normal serum alkaline phosphatase 43. Isoenzymes are activity ranges from (A) Chemically, immunologically and electro- (A) 1.0–5.0 KA units/100 ml phoretically different forms of an enzyme (B) 5.0–13.0 KA units/100 ml (B) Different forms of an enzyme similar in all (C) 0.8–2.3 KA units/100 ml properties (D) 13.0–21.0 KA units/100 ml (C) Catalysing different reactions (D) Having the same quaternary structures like 52. In early stages of myocardial ischemia the the enzymes most sensitive indicator is the measurement of the activity of 44. Isoenzymes can be characterized by (A) CPK (B) SGPT (A) Proteins lacking enzymatic activity that are (C) SGOT (D)LDH necessary for the activation of enzymes 53. Serum acid phosphatase level increases (B) Proteolytic enzymes activated by hydrolysis in (C) Enzymes with identical primary structure (A) Metastatic carcinoma of prostate (D) Similar enzymes that catalyse different reaction (B) Myocardial infarction (C) Wilson’s disease 45. The isoenzymes of LDH (D) Liver diseases (A) Differ only in a single amino acid 54. Serum alkaline phosphatase level (B) Differ in catalytic activity increases in (C) Exist in 5 forms depending on M and H (A) Hypothyroidism monomer contents (B) Carcinoma of prostate (D) Occur as monomers (C) Hyperparathyroidism 46. The normal value of CPK in serum varies (D) Myocardial ischemia between 55. Serum lipase level increases in (A) 4–60 IU/L (B) 60–250 IU/L (A) Paget’s disease (B) Gaucher’s disease (C) 4–17 IU/L (D) > 350 IU/L (C) Acute pancreatitis (D) Diabetes mellitus 47. Factors affecting enzyme activity: 56. Serum level decreases in (A) Concentration (B) pH (A) Gaucher’s disease (B) Cirrhosis of liver (C) Temperature (D) All of these (C) Acute pancreatitis (D) Wilson’s disease ENZYMES 143

57. The isoenzymes LDH5 is elevated in 65. The pH optima for salivary analyse is (A) Myocardial infarction (A) 6.6–6.8 (B) 2.0–7.5 (B) Peptic ulcer (C) 7.9 (D) 8.6 (C) Liver disease 66. The pH optima for pancreatic analyse is (D) Infectious diseases (A) 4.0 (B) 7.1 58. On the third day of onset of acute myo- (C) 7.9 (D) 8.6 cardial infarction the enzyme elevated is 67. The pH optima for is (A) Serum AST (B) Serum CK (A) 5.0–7.0 (B) 5.8–6.2 (C) Serum LDH (D) Serum ALT (C) 5.4–6.0 (D) 8.6

59. LDH1 and LDH2 are elevated in 68. The pH optima for is (A) Myocardial infarction (A) 1.0–2.0 (B) 5.2–6.0 (B) Liver disease (C) 5.8–6.2 (D) 5.4–6.0 (C) Kidney disease 69. The pH optima for lactase is (D) Brain disease (A) 1.0-2.0 (B) 5.4–6.0 60. The CK isoenzymes present in cardiac (C) 5.0–7.0 (D) 5.8–6.2 muscle is 70. The substrate for amylase is (A) BB and MB (B) MM and MB (A) Cane sugar (B) Starch (C) BB only (D) MB only (C) Lactose (D) Ribose 61. In acute pancreatitis, the enzyme raised 71. The ion which activates salivary amylase in first five days is activity is (A) Serum amylase (A) Chloride (B) Bicarbonate (B) Serum lactic dehydrogenase (C) Sodium (D) Potassium (C) Urinary lipase 72. The pancreatic amylase activity is in- (D) Urinary amylase creased in the presence of 62. Acute pancreatitis is characterised by (A) Hydrochloric acid (B) Bile salts (A) Lack of synthesis of zymogen enzymes (C) Thiocyanate ions (D) Calcium ions (B) Continuous release of zymogen enzymes into 73. A carbohydrate which can not be digest- the gut ed in human gut is (C) Premature activation of zymogen enzymes (A) Cellulose (B) Starch (D) Inactivation of zymogen enzymes (C) Glycogen (D) Maltose 63. An example of functional plasma enzyme is 74. The sugar absorbed by facilitated (A) Lipoprotein lipase diffusion and requiring Na independent transporter is (B) Amylase (C) Aminotransferase (A) Glucose (B) Fructose (D) Lactate dehydrogenase (C) Galactose (D) Ribose 75. In the intestine the rate of absorption is 64. A non-functional plasma enzyme is highest for (A) Psudocholinesterase (A) Glucose and galactose (B) Lipoprotein lipase (B) Fructose and mannose (C) Proenzyme of blood coagulation (C) Fructose and pentose (D) Lipase (D) Mannose and pentose 144 MCQs IN BIOCHEMISTRY

76. Glucose absorption is promoted by 84. In the glycolytic pathway, enolpyruvate (A) Vitamin A (B) Thiamin is converted to ketopyruvate by (C) Vitamin C (D) Vitamin K (A) Pyruvate kinase 77. The harmone acting directly on intestinal (B) Phosphoenolpyruvate mucosa and stimulating glucose absorption (C) Pyruvate dehydrogenase is (D) Spontaneously (A) Insulin (B) Glucagon 85. In erythrocytes, 2, 3-biphosphoglycerate (C) Thyroxine (D) Vasopressin is derived from the intermediate: 78. Given that the standard free energy (A) Glyeraldehyde-3-phosphate change (∆∆∆G°) for the hydrolysis of ATP is (B) 1, 3-Biphosphoglycerate –7.3 K cal/mol and that for the hydrolysis (C) 3-Phosphoglycerate of Glucose 6-phosphate is –3.3 Kcal/mol, the ∆∆∆G° for the phosphorylation of (D) 2-Phosphoglycerate glucose is Glucose + ATP →→→ Glucose 6– 86. 2, 3-Biphosphoglycerate in high concen- Phosphate + ADP. trations, combines with hemoglobin, (A) –10.6 Kcal/mol (B) –7.3 Kcal/mol causes (C) –4.0 Kcal/mol (D) +4.0 Kcal/mol (A) Displacement of the oxyhemoglobin 79. At low blood glucose concentration, brain dissociation curve to the left but not liver will take up glucose. It is due (B) Displacement of the oxyhemoglobin to the dissociation curve to the right

(A) Low Km of hexokinase (C) No change in oxy hemoglobin dissociation curve

(B) Low Km of glucokinase (D) Increased affinity for oxygen (C) Specificity of glucokinase 87. Erythrocytes under normal conditions and (D) Blood brain barrier microorganisms under anaerobic condi- 80. In the reaction below, Nu TP stands for tions may accumulate NuTP + glucose →→→ Glucose 6–Phosphate (A) NADPH + NuDP. (B) Pyruvate (A) ATP (B) CTP (C) Phosphoenolpyruvate (C) GTP (D)UTP (D) Lactate

81. In the figures shown below, fructose 1,6- 88. Enzymes leading to the high energy biphosphate is located at point: phosphorylation of substrates during (A) A (B) B glycolysis include which of the following? (C) C (D)D (A) Phosphoglycerate kinase 82. The enzyme of the glycolic pathway, (B) Enolase sensitive to inhibiton by fluoride ions is (C) Pyruvate Kinase (A) Hexokinase (B) Aldolase (D) Glyceraldehyde-3-phosphate dehydrogenase (C) Enolase (D) Pyruvate kinase 89. Lineweaver – Burk double reciprocal plot 83. In glycolytic pathway, iodacetate inhibits is related to the activity of the enzyme: (A) Substrate concentration (A) Phosphotriose isomerase (B) Enzyme activity (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Temperature (C) Pyruvate kinase (D) Both (A) and (B) (D) Phosphofructokinase ENZYMES 145

90. Phosphofructokinase key enzyme in 97. Pyruvate dehydrogenase activity is glycolysis is inhibited by inhibited by (A) Citrate and ATP (B) AMP (A) Mercury (B) Zinc (C) ADP (D) TMP (C) Calcium (D) Sodium 98. In the normal resting state of humans, 91. One of the enzymes regulating glycolysis most of the blood glucose burned as fuel is is consumed by (A) Phosphofructokinase (A) Liver (B) Adipose tissue (B) Glyceraldehyde-3-phosphate dehydrogenase (C) Muscle (D) Brain (C) Phosphotriose isomerase 99. All the enzymes of glycolysis pathway are (D) Phosphohexose isomerase found in 92. Hexokinase is inhibited in an allosteric (A) Extramitochondrial soluble fraction of the cell manner by (B) Mitochondria (A) Glucose-6-Phosphate (C) Nucleus (B) Glucose-1-Phosphate (D) Endoplasmic reticulum (C) Fructose-6-phosphate 100. Most major metabolic pathways are con- (D) Fructose-1, 6-biphosphate sidered mainly either anabolic or cata- bolic. Which of the following pathway 93. A reaction which may be considered an is most correctly considered to be am- isomerisation is phibolic? (A) Citric acid cycle (B) Gluconeogenesis (A) Glucose 6-Phosphate fructose 6 phosphate (C) Lipolysis (D) Glycolysis (B) 3-Phosphoglycerate 2-phosphoglycerate 101. The enzymes of the citric acid cycle are (C) 2-phosphoglycerate phosphoenol- located in pyruvate (A) Mitochondrial matrix (B) Extramitochondrial soluble fraction of the cell (D) Pyruvate Lactate (C) Nucleus 94. The net number of ATP formed per mole (D) Endoplasmic reticulum of glucose in anaerobic glycolysis is 102. The initial step of the citric acid cycle is (A) 1 (B) 2 (A) Conversion of pyruvate to acetyl-CoA (C) 6 (D) 8 (B) Condensation of acetyl-CoA with oxaloacetate 95. Pyruvate dehydrogenase a multienzyme (C) Conversion of citrate to isocitrate complex is required for the production of (D) Formation of α -ketoglutarate catalysed by isocitrate dehydrogenase (A) Acetyl-CoA (B) Lactate 103. The substance which may be considered to play a catalytic role in citric acid cycle is (C) Phosphoenolpyruvate (A) Oxaloacetate (B) Isocitrate (D) Enolpyruvate (C) Malate (D) Fumarate 96. Dietary deficiency of thiamin inhibits the 104. An enzyme of the citric acid cycle also activity of the enzyme: found outside the mitochondria is (A) Pyruvate kinase (A) Isocitrate dehydrogenase (B) Pyruvate dehydrogenase (B) Citrate synthetase (C) Phosphofructokinase (C) α-Ketoglutarate dehydrogenase (D) Enolase (D) Malate dehydrogenase 146 MCQs IN BIOCHEMISTRY

105. The reaction catalysed by ααα-ketoglutarate 111. Formation of succinyl-CoA from ααα-Keto- dehydrogenase in the citric acid cycle glutarate is inhibited by requires (A) Fluoroacetate (B) Arsenite (A) NAD (B) NADP (C) Fluoride (D) Iodoacetate (C) ADP (D) ATP 112. The number of ATP molecules generated 106. If all the enzymes, intermediates and for each turn of the citric acid cycle is cofactors of the citric acid cycle as well as an excess of the starting substrate acetyl- (A) 8 (B) 12 CoA are present and functional in an (C) 24 (D) 38 organelle free solution at the appropriate 113. Oxidation of one molecule of glucose pH, which of the following factors of the yields citric acid cycle would prove to be rate limiting? (A) 12 ATP (B) 24 ATP (A) Molecular oxygen (C) 38 ATP (D) 38 ATP (B) Half life of enzyme 114. Which of the following intermediates of (C) Turnover of intermediates metabolism can be both a precursor and (D) Reduction of cofactors a product of glucose? 107. In TCA cycle, oxalosuccinate is converted (A) Lactate (B) Pyruvate to ααα-ketoglutarate by the enzyme: (C) Alanine (D) Acetyl-CoA (A) Fumarase 115. Mitochondrial membrane is freely (B) Isocitrate dehydrogenase preamble to (C) Aconitase (A) Pyruvate (B) Malate (D) Succinase (C) Oxaloacetate (D) Fumarate 108. The enzyme -ketoglutarate dehydrogena- 116. The reaction of Kreb’s cycle which does se in the citric acid cycle requires not require cofactor of vitamin B group is (A) Lipoate (B) Folate (C) Pyridoxine (D) Inositol (A) Citrate isocitrate 109. The example of generation of a high (B) α -Ketoglutarate succinate energy phosphate at the substrate level (C) Malate oxaloacetate in the citric acid cycle is the reaction: (D) Succinate fumarate (A) Isocitrate α-Ketoglutarate (B) Succinate α-fumarate 117. The coenzyme not involved in the formation of acetyl-CoA from pyruvate is (C) Malate α-oxaloacetate (A)TPP (B) Biotin (D) Succinyl CoA α-Succinate (C) NAD (D) FAD

110. Fluoroacetate inhibits the reaction of citric 118. A carrier molecule in the citric acid cycle is acid cycle: (A) Acetyl-CoA (B) Citrate (A) Isocitrate α-Ketoglutarate (C) Oxaloacetate (D) Malate

(B) Fumarate α-Malate 119. A specific inhibitor for succinate dehydro- genase is (C) Citrate -cis-aconitate α (A) Arsenine (B) Arsenite (D) Succinate α-fumarate (C) Citrate (D) Fluoride ENZYMES 147

120. The rate of citric acid cycle is controlled 127. In glycogenolysis, the enzyme which by the allosteric enzyme: transfers a trisaccharide unit from one (A) Aconitase branch to the other exposing 1→→→ 6 branch (B) Fumarase point is (C) Fumarase (A) Phosphorylase (D) Malate dehydrogenase (B) α-[1→ 4]→ α-[1→ 4]→ Glucan transferase (C) Amylo [1→ 6] glucosidase 121. In the erythrocytes, the net production of ATP molecules by the Rapport-Leubering (D) Amylo[1→ 4]→ [1→ 6] transglucosidase pathway is 128. In the synthesis of glycogen from glucose (A) 0 (B) 2 the reversible step is (C) 4 (D) 8 (A) Glucose → glucose 6-phosphate 122. The ratio that most closely approximates (B) Glucose 6-phosphate → glucose 1-phosphate the number of net molecules of ATP (C) Glucose 1-phosphate → UDP glucose formed per mole of glucose utilized under (D) UDP glucose → glycogen aerobic conditions to the net number formed under anaerobic conditions is 129. The enzyme glucose-6-phosphatase (A) 4:1 (B) 13:1 which catalyses the conversion of glucose 6-phosphate to glucose is not found in (C) 18:1 (D) 24:1 (A) Liver (B) Muscle 123. The pathway of glycogen biosynthesis (C) Intestine (D) Kidney involves a special nucleotide of glucose. In the reaction below, NuDP stands for 130. Allosteric activator of glycogen synthase is NuDP Glucose + glycogenn → NuDP + glycogenn+1 (A) ADP (B) GDP (A) Glucose (B) Glucose-6-Phosphate (C) UDP (D) CDP (C) UTP (D) Glucose-1-phosphate 124. Glucose 6-phosphate is converted to glu- 131. Action of glycogen synthase is inhibited by cose 1-phosphate in a reaction catalysed (A) Insulin (B) Glucose by the enzyme phosphoglucomutase, (C) Mg2+ (D) Cyclic AMP which is (A) Phosphorylated 132. The hormone activating the glycogen synthase activity is (B) Dephosphorylated (C) Phosphorylated-dephosphorylated (A) Insulin (B) Glucagon (D) Phosphorylated-dephosphorylatedrephos- (C) Epinephrine (D) ACTH phorylated 133. Characteristic features of active site are 125. The glycogen content of the liver is upto (A) Flexible in nature (B) Site of binding (A) 6% (B) 8% (C) Acidic (D) Both (A) and (B) (C) 10% (D) 12% 134. Von Gierke’s disease is characterized by 126. In glycogenesis a branch point in the the deficiency of molecule is established by the enzyme (A) Glucose-6-phosphatase (A) Amylo[1→ 4][1→ 6] transglucosidase (B) α -1 → 4 Glucosidase (B) α [1→ 4] α [1→ 4] Glucan transferase (C) 1 → 6 Glucosidase (C) Amylo [1→ 6] glucosidase (D) Liver phosphorylase (D) Glycogen synthase 148 MCQs IN BIOCHEMISTRY

135. Cori disease (Limit dextrinosis) is caused 142. The hydrogen acceptor used in pentose due to absence of phosphate pathway is (A) Branching enzyme (A) NAD (B) NADP (B) Debranching enzyme (C) FAD (D) FMN (C) Glycogen synthase 143. The enzymes of the pentose phosphate (D) Phosphorylase pathway are found in the 136. Mc Ardle’s syndrome is characterized by (A) Cytosol the absence of (B) Mitochondria (A) Liver phosphorylase (C) Nucleus (B) Muscle phosphorylase (D) Endoplasmic reticulum (C) Branching enzyme (D) Debranching enzyme 144. In pentose phosphate pathway, D-ribulose- 137. Pompe’s disease is caused due to 5-phosphate is converted to D-ribose-5- deficiency of phosphate by the enzyme: (A) Lysosomal α-1→4 and 1→6-glucosidase (A) Fumarase (B) Ketoisomerase (B) Glucose-6-phosphatase (C) G-6-PD (D) Epimerase (C) Glycogen synthase 145. The transketolase enzyme in the pentose (D) Phosphofructokinase phosphate pathway requires the B 138. Amylopectinosis is caused due to absence vitamin. of (A) Pantothenic acid (B) Thiamin (A) Debranching enzyme (C) Riboflavin (D) Nicotinic acid (B) Branching enzyme 146. Xylulose-5-phosphate serves as a donar (C) Acid maltase of active glycolaldehyde, the acceptor is (D) Glucose-6-phosphatase (A) Erythrose 4-phosphate 139. Her’s disease is characterized by deficien- cy of (B) Ribose 5-phosphate (C) Glyceraldehyde 3-phosphate (A) Muscle phosphorylase (B) Liver phosphorylase (D) Sedoheptulose 7-phosphate (C) Debranching enzyme 147. Pentose phosphate pathway is of signif- (D) Glycogen synthase icance because it generates 140. Tarui disease is characterized by the (A) NADPH for reductive synthesis deficiency of the enzyme: (B) Regenerates glucose 6-phosphate (A) Liver phosphorylase (C) Generates fructose 6-phosphate (B) Muscle phosphorylase (D) Forms glyceraldehyde 3-phosphate (C) Muscle and erythrocyte phosphofructokinase 148. The pentose phosphate pathway protects (D) Lysosomal acid maltase erythrocytes against hemolysis by assis- 141. The hexose monophosphate pathway ting the enzyme: includes the enzyme: (A) Superoxide (A) Maltase dehydrogenase (B) Catalase (B) Hexokinase (C) Glutathionic peroxidase (C) α-Ketoglutarate dehydrogenase (D) Cytochrome oxidase (D) Glucose-6-phosphate dehydrogenase ENZYMES 149

149. Hemolytic anemia is caused by the 157. For conjugation with many enogenous deficiency of certain enzymes of the and exogenous substances before eli- pentose phosphate pathway, the mination in urine, the uronic acid path- principal enzyme involved is way provides (A) Glucose-6-phosphate dehydrogenase (A) Active glucuronate (B) Gulonate (B) Aldolase (C) Xylulose (D) Xylitol (C) Fructose 1, 6-bisphosphatase 158. UDP glucose is converted to UDP (D) Phosphohexose isomerase glucurronate, a reaction catalysed by UDP 150. The sites for gluconeogenesis are glucose dehydrogenase requires (A) Liver and kidney (A) NAD+ (B) FAD (B) Skin and pancreas (C) NADP (D) FMN (C) Lung and brain 159. Pentosuria is a rare hereditary disease is (D) Intestine and lens of eye characterized by increased urinary 151. An enzyme involved in gluconeogenesis is excretion of (A) Pyruvate kinase (A) L-xylulose (B) Pyruvate carboxylase (B) Xylitol (C) Hexokinase (C) Xylulose 5-phosphate (D) Phosphohexose isomerase (D) Ribose 5-phosphate 152. The enzyme pyruvate carboxylase is 160. The enzyme involved in essential present in pentosuria is (A) Cytosol (B) Mitochondria (A) Reductase (B) Hydroxylase (C) Nucleus (D) Golgi bodies (C) Isomerase (D) Racemase 153. The enzyme phosphoenolpyruvate 161. Galactose is synthesized from glucose in carboxykinase catalyses the conversion of oxaloacetate to phosphoenolpyruvate (A) Mammary gland (B) Intestine requires (C) Kidney (D) Adipose tissue (A) ATP (B) ADP 162. Galactose is readily converted to glucose in (C) AMP (D)GTP (A) Liver (B) Intestine 154. The enzyme glucose 6-phosphatase is (C) Kidney (D) Adipose tissue present in 163. Galactose 1-phosphate is converted to (A) Liver (B) Muscle uridine diphosphate galactose, the (C) Adipose tissue (D) Brain reaction is catalysed by the enzyme: 155. In gluconeogensis, an allosteric activator (A) Glactokinase required in the synthesis of oxaloacetate (B) Galactose 1-phosphate uridyl transferase from bicarbonate and pyruvate, which is catalysed by the enzyme pyruvate (C) Uridine diphospho galactose 4-epimerase carboxylase is (D) UDP glucose pyrophosphorylase (A) Acetyl CoA (B) Succinate 164. The best known cause of galactosemia is (C) Isocitrate (D) Citrate the deficiency of 156. The number of ATP molecules required to (A) Galactose 1-phosphate and uridyl transferase convert 2 molecules of lactate into glucose (B) Phosphoglucomutase in mammalian liver is (C) Galactokinase (A) 2 (B) 4 (D) (C) 5 (D) 6 150 MCQs IN BIOCHEMISTRY

165 Conversion of fructose to sorbitol is 172. Phlorizin inhibits catalysed by the enzyme: (A) Renal tubular reabsorption of glucose (A) (B) Glycolysis (B) (C) Gluconeogenesis (C) Fructokinase (D) Glycogenolysis (D) Hexokinase 173. Renal glycosuria is characterized by 166. A specific fructokinase present in liver has a very high affinity for its substrate (A) Hyperglycemia because (B) Hyperglycemia with glycosuria (C) Normal blood glucose level with glycosuria (A) Km for fructose is very high (D) Hyperglycemia with ketosis (B) Km for fructose is very low (C) Activity is affected by fasting 174. Acute hemolytic anemia in person’s sen- (D) Activity is affected by insulin sitive to the Fava beans is due to the defi- 167. Insulin has no effect on the activity of the ciency of the enzyme: enzyme: (A) Pyruvate dehydrogenase (A) Glycogen synthetase (B) G-6-PD (B) Fructokinase (C) Aconitase (C) Pyruvate kinase (D) Transketolase (D) Pyruvate dehydrogenase 175 Acute hemolytic episode after administra- 168. The pathogenesis of diabetic cataract tion of antimalarial, primaquin, is due to involves accumulation of deficiency of the enzyme: (A) Galactose (B) Mannitol (A) 6-Phosphogluconate dehydrogenase (C) Sorbitol (D) Pyruvate (B) Glucose-6-phosphate dehydrogenase 169. Hereditary fructose intolerance involves (C) Epimerase the absence of the enzyme: (D) Transketolase

(A) Aldalose B 176. The pH optima of gastric lipase is (B) Fructokinase (A) 3.0–6.0 (B) 1.0–2.0 (C) Triokinase (C) 8.0 (D) 8.6 (D) Phosphotriose isomerase 177. The optimum pH of pancreatic lipase is 170. Essential fructosuria is characterized by the lack of the hepatic enzyme: (A) 2.0 (B) 4.0 (A) Phosphohexose isomerase (C) 6.0 (D) 8.0 (B) Aldalose A 178. Gastric lipae is activated in the presence (C) Aldolase B of (D) Fructokinase (A) Bile salts (B) Cu++ 171. In normal individuals glycosuria occurs (C) K+ (D) Na+ when the venous blood glucose concen- tration exceeds 179. An example of enzyme inhibition: (A) 5–6 mmol/L (A) Reversible inhibition (B) 7–8 mmol/L (B) Irreversible inhibition (C) 8.5–9 mmol/L (C) Allosteric inhibition (D) 9.5–10 mmol/L (D) All of these ENZYMES 151

180. The formation of ∆∆∆2-trans-enoyl-CoA from 189. The concentration of ketone bodies in the acyl-CoA requires the enzyme: blood does not normally exceed (A) Acyl-CoA synthetase (A) 0.2 mmol/L (B) 0.4 mmol/L (B) Acyl-CoA dehydrogenase (C) 1 mmol/L (D) 2 mmol/L (C) 3-Hydroxy acyl-CoA dehydrogenase 190. In humans under normal conditions loss (D) Thiolase of ketone bodies via urine is usually less than 181. In βββ-oxidation 3-ketoacyl-CoA is splitted at the 2, 3 position by the enzyme: (A) 1 mg/24 hr (B) 4 mg/24 hr (A) Hydratase (B) Dehydrogenase (C) 8 mg/24 hr (D) 10 mg/24 hr (C) Reducatse (D) Thiolase 191. The structure which appears to be the only organ to add significant quantities of 182. Fatty acids with odd number of carbon ketone bodies to the blood is atoms yield acetyl-CoA and a molecule of (A) Brain (B) Erythrocytes (A) Succinyl-CoA (B) Propionyl-CoA (C) Liver (D) Skeletal muscle (C) Malonyl-CoA (D) Acetoacetyl-CoA 192. The starting material for ketogenesis is 183 For each of the first 7-acetyl-CoA molecules formed by ααα-oxidation of palmitic acid, (A) Acyl-CoA (B) Acetyl-CoA the yield of high energy phosphates is (C) Acetoacetyl-CoA (D) Malonyl-CoA (A) 12 (B) 24 193. Enzymes responsible for ketone body (C) 30 (D) 35 formation are associated mainly with the 184. The net gain of ATP/mol of palmitic acid (A) Mitochondria on complete oxidation is (B) Endoplasmic reticulum (A) 88 (B) 105 (C) Nucleus (C) 129 (D) 135 (D) Golgi apparatus 194. The synthesis of 3-hydroxy-3-methyl- 185. ωωω-oxidation is normally a very minor pathway and is brought by hydroxylase glutaryl-CoA can occur enzymes involving (A) Only in mitochondria of all mammalian tissues (A) Cytochrome a (B) Cytochrome b (B) Only in the cytosol of all mammalian tissue (C) Cytochrome c (D) Cytochrome p-450 (C) In both cytosol and mitochondria (D) In lysosomes 186. ααα-Oxidation i.e., the removal of one carbon at a time from the carboxyl end 195. In the pathway leading to biosynthesis of the molecule has been detected in of acetoacetate from acetyl-CoA in liver, the immediate precursor of aceotacetate (A) Brain tissue (B) Liver is (C) Adipose tissue (D) Intestine (A) Acetoacetyl-CoA 187. In βββ-oxidation, the coenzyme for acyl-CoA (B) 3-Hydroxybutyryl-CoA dehydrogenase is (C) 3-Hydroxy-3-methyl-glutaryl-CoA (A) FMN (B) NAD (D) 3-Hydroxybutyrate (C) NADP (D) FAD 196. Ketone bodies serve as a fuel for 188. The coenzyme involved in dehydrogena- (A) Extrahepatic tissues tion of 3-hydroxy acyl-CoA is (B) Hepatic tissues (A) FAD (B) FMN (C) Erythrocytes (C) NAD (D) NADP (D) Mitochondria 152 MCQs IN BIOCHEMISTRY

197. In extra hepatic tissues, one mechanism 205. The complex catalyses for utilization of acetoacetate involves (A) 4 sequential enzymatic steps (A) Malonyl-CoA (B) Succinyl-CoA (B) 6 sequential enzymatic steps (C) Propionyl-CoA (D) Acetyl-CoA (C) 7 sequential enzymatic steps (D) 8 sequential enzymatic steps 198. Ketosis reflects (A) Increased hepatic glucose liberation 206. The main source of reducing equivalents (NADPH) for lipogenesis is (B) Increased fatty acid oxidation (A) Pentose phosphate pathway (C) Increased carbohydrate utilisation (B) Citric acid cycle (D) Incresed gluconeogenesis (C) Glycolysis 199. Ketosis is associated with the disease: (D) Glycogenolysis (A) Nephritis 207. In fatty acids synthase of both bacteria (B) Diabetes mellitus and mammals, ACP (acyl carrier protein) (C) Edema contain the vitamin: (D) Coronary artery diseases (A) Thiamin (B) Pyridoxine (C) Riboflavin (D) Pantothenic acid 200. The main pathway for denovo synthesis of fatty acids occur in 208. Carboxylation of acetyl-CoA to malonyl- CoA requires the enzyme: (A) Cytosol (B) Mitochondria (C) Microsomes (D) Nucleus (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase 201. Chain elongation of fatty acids in (C) Acetyl transacylase mammalian liver occurs in (D) Acyl CoA-synthetase (A) Nucleus (B) Ribosomes 209. The rate limiting reaction in the lipogenic (C) Lysosomes (D) Microsomes pathway is 202. Acetyl-CoA is the principal building block (A) Acetyl-CoA carboxylase step of fatty acids. It is produced within the (B) Ketoacyl synthase step mitochondria and does not diffuse readily (C) Ketoacyl reductase step into cytosol. The availability of acetyl CoA (D) Hydratase step involves 210. Conversion of fatty acyl-CoA to an acyl- (A) Carnitine acyl transferase CoA derivative having 2 more carbon (B) Pyruvate dehydrogenase atoms involves as acetyl donar: (C) Citrate lyase (A) Acetyl-CoA (B) Succinyl-CoA (D) Thiolase (C) Propionyl-CoA (D) Malonyl-CoA 203. The synthesis of fatty acids is often termed 211. A cofactor required for the conversion of reductive synthesis. acetyl-CoA to malonyl-CoA in extramito- (A) NADP+ (B) NADH chondrial fatty acid synthesis is (A) Biotin (B)FMN (C) FADH2 (D) NADPH (C) NAD (D) NADP 204. The protein, which is in fact a multifunc- tional enzyme complex in higher organ- 212. The glycerol for fatty acid esterification in ism is adipocytes is (A) Acetyl transacylase (A) For the most part, derived from glucose (B) Malonyl transacylase (B) Obtained primarily from phosphorylation of glycerol by glycerol kinase (C) 3-Hydroxy acyl-ACP dehyratase (C) Formed from gluconeogenesis (D) Fatty acid synthase (D) Formed from glycogenolysis ENZYMES 153

213. In the biosynthesis of triglycerides from 221. Synthesis of phosphatidylinositol by glycerol 3-phosphate and acyl-CoA, the transfer of inositol to CDP diacylglycerol first intermediate formed is is catalysed by the enzyme: (A) 2-Monoacylglycerol (A) CTP phosphatidate cytidyl transferase (B) 1, 2-Diacylglycerol (B) Phosphatidate phosphohydrolase (C) Lysophosphatidic acid (C) CDP-diacylglycerol inositol transferase (D) Phosphatidic acid (D) 214. The enzyme glycerol kinase is low activity 222. Synthesis of sphingosine requires the in cofactor (A) Liver (B) Kidney (A) NAD (B) NADP (C) Intestine (D) Adipose tissue (C) NADPH+ (D) ATP 215. The common precursor in the biosynthesis 223. Ceramide is formed by the combination of triacylglycerol and phospholipids is of sphingosine and (A) 1, 2-Diacylglycerol phosphate (A) Acetyl-CoA (B) Acyl-CoA (B) 1-Acylglycerol 3-phosphate (C) Malonyl-CoA (D) Propionyl-CoA (C) Glycerol 3-phosphate 224. The amino alcohol sphingosine is (D) Dihydroxyacetone phosphate synthesized in 216. Synthesis of polyunsaturated fatty acids (A) Mitochondria involves the enzyme systems: (B) Cytosol (C) Nucleus (A) Acyl transferase and hydratase (D) Endoplasmic reticulum (B) Desaturase and elongase (C) Ketoacyl-CoA reductase and hydratase 225. The output of free fatty acids from adipose (D) Dihydroxyacetone phosphate tissue is reduced by (A) Insulin (B) Glucagon 217. The desaturation and chain elongation system of polyunsaturated fatty acid are (C) Growth hormone (D) Epinephrine enhanced by 226. The principal action of insulin in adipose (A) Insulin (B) Glucagon tissue is to inhibit the activity of the (C) Epinephrine (D) Thyroxine (A) Hormone sensitive lipoprotein lipase (B) Glycerol phosphate 218. Higher rate of lipogenesis is associated with (C) Acetyl-CoA carboxylase (D) Pyruvate dehydrogenase (A) High proportion of carbohydrate in diet (B) Restricted caloric intake 227. In non shivering thermogenesis (C) High fat diet (A) Glucose is oxidized to lactate (D) Deficiency of insulin (B) Fatty acids uncouple oxidative phosphoryla- tion 219. Example of enzyme specificity: (C) Ethanol is formed (A) Stereo specificity (B) Reaction specificity (D) ATP is burned for heat production (C) Substrate specificity(D) All of these 228. Brown adipose tissue is 220. Phospholipase C attacks the ester bond (A) A prominent tissue in human liberating 1, 2-diacylglycerol and a (B) Characterised by high content of mitochon- phosphoryl base at position dria (A) 1 (B) 2 (C) Associated with high activity of ATP synthase (C) Both (A) and (B) (D) 3 (D) Characterised by low content of cytochromes 154 MCQs IN BIOCHEMISTRY

229. Fatty liver is caused due to accumulation 238. In the biosynthesis of cholesterol, the step of which controls the rate and locus of metabolic regulation is (A) Fatty acids (B) Cholesterol (C) Phospholipids (D) Triacylglycerol (A) Geranyl pyrophosphate farnesyl pyro- phosphate 230. A lipotropic factor is (B) Squalene → lanosterol (A) Choline (B) Palmitic acid (C) HMG CoA → mevalonate (C) Calcium (D) Vitamin C (D) Lanosterol → 1, 4-desmethyl lanosterol 231. Fatty liver is also caused by 239. The cyclisation of squalene in mammals results in the direct formation of the sterol. (A) CH Cl (B) CCl 3 4 (A) Cholesterol (B) Lanosterol (C) Na SO (D) Riboflavin 2 4 (C) Sistosterol (D) Zymosterol 232. All the enzymes involved in the synthesis 240. In the biosynthesis of cholesterol, the rate of cholesterol are found in limiting enzyme is (A) Mitochondria (A) Mevalonate kinase (B) Golgi apparatus (B) HMG-CoA synthetase (C) Nucleus (C) HMG-CoA reductase (D) Endoplasmic reticulum and cytosol (D) Cis-prenyl transferase 233. The source of all the carbon atoms in 241. Cholesterol by a feed back mechanism cholesterol is inhibits the activity of (A) Acetyl-CoA (B) Bicarbonate (A) HMG-CoA synthetase (C) Propionyl-CoA (D) Succinyl-CoA (B) HMG-CoA reductase (C) Thilase 234. Two molecules of acetyl-CoA condense to (D) Mevalonate kinase form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase 242. The activity of HMG-CoA reductase is inhibited by (C) Reductase (D) Isomerase (A) A fungal inhibitor mevastatin 235. Acetoacetyl-CoA condenses with one (B) Probucol more molecule of acetyl-CoA to form (C) Nicotinic acid (A) Mevalonate (D) Clofibrate (B) Acetoacetate 243. Hypolipidemic drugs reduce serum (C) β-Hydroxybutyrate cholesterol and triacylglycerol. The effect (D) 3-Hydroxy 3-methyl-glutaryl-CoA of clofibrate is attributed to 236. HMG-CoA is converted to mevalonate by (A) Block in absorption from G.I.T. reduction catalysed by (B) Decrease in secretion of triacylglycerol and cholesterol containing VLDL by liver (A) HMG-CoA synthetase (C) Block in the reabsorption of bile acids (B) HMG-CoA reductase (D) Decreased synthesis of cholesterol (C) Mevalonate kinase (D) Thiolase 244. In biosynthesis of cholesterol triparanol inhibits the activity of the enzyme: 237. For reduction enzyme HMG-CoA reductase 24 requires cofactor: (A) ∆ Reductase (B) Oxidosqualene-lanosterol cyclase (A) NADPH (B) NADP (C) Isomerase (C) NAD (D) FAD (D) Squalene epoxidase ENZYMES 155

245. HMG-CoA reductase activity is increased 253. Defective enzyme in Hunter’s syndrome by administration of the hormone: is (A) Insulin (B) Glucagon (A) α-L- (B) Iduronate sulphatase (C) Epinephrine (D) Glucocorticoids (C) Arylsulphatase B (D) C-acetyl transferase 246. The principal sterol excreted in feces is 254. In Hunter’s syndrome (A) Coprostanol (B) Zymosterol (A) There is progressive corneal opacity (C) Lanosterol (D) Desmosterol (B) Keratan sulphate is excreted in the urine (C) Enzyme defective is arylsulphatase B 247. The principal rate limiting step in the (D) Hearing loss is perceptive biosynthesis of bile acids is at the (A) 7-Hydroxylase reaction 255. An important feature of Von-Gierke’s disease is (B) 12 α-Hydroxylase reaction (A) Muscle cramps (B) Cardiac failure (C) Conjugation reaction (C) Hypoglycemia (D) Respiratory alkalosis (D) Deconjugation reaction 256. The affected organ in Mc Ardle’s syndrome 248. Hypercholesterolemia is found in is (A) Xanthomatosis (A) Liver (B) Kidney (B) Thyrotoxicosis (C) Liver and Heart (D) Skeletal muscle (C) Hemolytic jaundice 257. Refsum’s disease is due to deficiency of (D) Malabsorption syndrom the enzyme: 249. Hypocholesterolemia is found in (A) Pytantate-α-oxidase (A) Thyrotoxicosis (B) Glucocerebrosidase (B) Diabetes mellitus (C) Galactocerebrosidase (C) Obstructive jaundice (D) Ceramide trihexosidase (D) Nephrotic syndrome 258. An important finding in Refsum’s disease 250. The major source of extracellular is cholesterol for human tissue is (A) Accumulation of ceramide trihexoside in the kidney (A) Very low density lipoprotein (B) Accumulation of phytanic acid in the blood (B) High density lipoprotein and tissues (C) Low density lipoprotein (C) Accumulation of gangliosides in brain and (D) Albumin spleen 251. Correct ordering of lipoprotein molecules (D) Skin eruptions from lowest to the greater density is 259. ααα-Galactosidase enzyme is defective in (A) LDL, IDL, VLDL, chylomicron (A) Tay-sach’s disease (B) Chylomicron, VLDL, IDL, LDL (B) Refsum’s disease (C) VLDL, IDL, LDL, chylomicron (C) Sandhoff’s disease (D) LDL, VLDL, IDL, chylomicron (D) Fabry’s disease 252. In Hurler’s syndrome, urine shows the 260. The hypothesis to explain enzyme– presence of substrate complex formation: (A) Keratan sulphate I (A) Lock and key model (B) Chondroitin sulphate (B) Induced fit theory (C) Dermatan sulphate and heparan sulphate (C) Proenzyme theory (D) Keratan sulphate II (D) Both (A) and (B) 156 MCQs IN BIOCHEMISTRY

261. An important finding in Tay-sach’s disease is 269. Bassen-Kornzweig syndrome is due to (A) Renal failure (A) Absence of Apo-C-II (B) Accumulation of gangliosides in brain and (B) Defect in Apo-B synthesis spleen (C) Absence of Apo-E (C) Cardiac failure (D) Absence of Apo-D (D) Anemia 270. Enzyme deficient in Hyperammonemia 262. The enzyme deficient in Krabbe’s disease is type II is (A) Hexosaminidase A (B) Arylsuphatase A (A) Glutamine synthetase (C) β-Galactosidase (D) α-Fucosidase (B) 263. The enzyme ceramidase is deficient in (C) Ornithine transcarbamoylase (A) Farber’s disease (B) Fabry’s disease (D) Carbamoylphosphate synthetase (C) Sandhoff’s disease(D) Refsum’s disease 271. An important finding in Hyperammone- mia type II is 264. Niemann-Pick disease is due to deficiency of the enzyme (A) Increased serum gluatmine level (A) Ceramidase (B) Enlarged liver (B) Glucocerebrosidase (C) Mental retardation (C) Galactocerebrosidase (D) Increased carbamoyl phosphate synthetase level (D) Sphingomyelinase 272. Absence of the enzyme argininosuccinate 265. Wolman’s disease is due to deficiency of synthetase causes (A) Cholesteryl ester hydrolase (A) Argininosuccinic aciduria (B) Hexosaminidase A (B) Hyperargininemia (C) α-Fucosidase (C) Tricorrhexis nodosa (D) Arylsulphatase A (D) Citrullinemia 266. The enzyme deficient in Sandhoff’s disease 273. Tricorrhexis nodosa is a characteristic find- is ing of (A) α-Fucosidase (A) Argininosuccinic aciduria (B) Hexosaminidase A and B (B) Citrullinemia (C) β-Galactosidase (C) Phenylketonuria (D) β-Glucosidase (D) Hyperargininemia 267. Jamaican vomiting sickness is due to 274. Elevated blood argininosuccinate level is inactivation of the enzyme found in (A) Pyruvate carboxylase (A) Hyperargininemia (B) Acyl-Co-A synthetase (B) Argininosuccinic aciduria (C) Acyl-Co-A dehydrogense (C) Citrullinemia (D) Thiolase (D) Tyrosinosis 268. Zellweger’s syndrome is due to inherited 275. Hyperargininemia, a defect in urea syn- absence of thesis develops due to deficiency of the (A) Peroxisomes enzyme:

(B) Phospholipase A1 (A) Ornithine transcarbamoylase (C) Acyl-Co-A dehydrogenase (B) Argininosuccinase (D) Thiolase (C) Arginase (D) Argininosuccinate synthetase ENZYMES 157

276. Albinism is due to deficiency of the enzyme: 284. A coenzyme required in transamination (A) Phenylalanine hydroxylase reactions is (B) Tyrosinase (A) Coenzyme A (B) Coenzyme Q (C) p-Hydroxyphenylpyruvic acid oxidase (C) Biotin (D) Pyridoxal phosphate (D) Tyrosine dehydrogenase 285. Coenzyme A contains a vitamin which is 277. Neonatal tyrosinemia is due to deficiency (A) Thiamin (B) Ascorbic acid of the enzyme: (C) Pantothenic acid (D) Niacinamide (A) p-Hydroxyphenylpyruvate hydroxylase 286. Cobamides contain a vitamin which is (B) Fumarylacetoacetate hydrolase (A) Folic acid (B) Ascorbic acid (C) Phenylalanine hydroxylase (C) Pantothenic acid (D) Vitamin B (D) Tyrosine dehydrogenase 12 287. A coenzyme required in carboxylation 278. Which of the following is a substrate- reactions is specific enzyme? (A) Hexokinase (B) Thiokinase (A) Lipoic acid (B) Coenzyme A (C) Lactase (D) Aminopeptidase (C) Biotin (D) All of these 279. Coenzymes combine with 288. Which of the following coenzyme takes part in tissue respiration? (A) Proenzymes (B) Apoenzymes (A) Coenzyme Q (B) Coenzyme A (C) Holoenzymes (D) Antienzymes (C) NADP (D) Cobamide 280. Coenzymes are required in which of the following reactions? 289. The enzyme hexokinase is a (A) Oxidation-reduction (A) Hydrolase (B) (B) Transamination (C) Transferase (D) Ligase (C) Phosphorylation 290. Which of the following is a proteolytic (D) All of these enzyme? 281. Which of the following coenzyme takes (A) Pepsin (B) Trypsin part in hydrogen transfer reactions? (C) Chymotrypsin (D) All of these (A) Tetrahydrofolate (B) Coenzyme A 291. Enzymes which catalyse binding of two (C) Coenzyme Q (D) Biotin substrates by covalent bonds are known as 282. Which of the following coenzyme takes (A) Lyases (B) part in oxidation-reduction reactions? (C) Ligases (D) (A) Pyridoxal phosphate 292. The induced fit model of enzyme action (B) Lipoic acid was proposed by (C) Thiamin diphosphate (A) Fischer (B) Koshland (D) None of these (C) Mitchell (D) Markert 283. In conversion of glucose to glucose-6- 293. Allosteric inhibition is also known as phsophate, the coenzyme is (A) Competitive inhibition (A) Mg++ (B) Non-competitive inhibition (B) ATP (C) Feedback inhibition (C) Both (A) and (B) (D) None of these (D) None of these 158 MCQs IN BIOCHEMISTRY

294. An allosteric enzyme is generally inhibit- 302. Serum lactate dehydrogenase rises in ed by (A) Viral hepatitis (A) Initial substrate of the pathway (B) Myocardial infarction (B) Substrate analogues (C) Carcinomatosis (C) Product of the reaction catalysed by allosteric (D) All of these enzyme 303. Which of the following serum enzyme (D) Product of the pathway rises in myocardial infarction: 295. When the velocity of an enzymatic reaction (A) (B) GOT equals V , substrate concentration is max (C) LDH (D) All of these (A) Half of Km (B) Equal to Km (C) Twice the K (D) Far above the K 304. From the following myocardial infarction, m m the earliest serum enzyme to rise is 296. In Lineweaver-Burk plot, the y-intercept (A) Creatine Kinase (B) GOT represents (C) GPT (D) LDH (A) Vmax (B) Km 305. Proenzymes: (C) Km (D) 1/Km (A) Chymotrysinogen (B) Pepsinogen 297. In competitive inhibition, the inhibitor (C) Both (A) and (B) (D) None of these (A) Competes with the enzyme (B) Irreversibly binds with the enzyme 306. Alkaline phosphatase is present in (C) Binds with the substrate (A) Liver (B) Bones (D) Competes with the substrate (C) Placenta (D) All of these 298 Competitive inhibitors 307. Which of the following isoenzyme of lactate dehydrogenase is raised in serum (A) Decrease the K (B) Decrease the V m max in myocardial infarction: (C) Increase the Km (D) Increase the Vmax (A) LD1 (B) LD2 299. Competitive inhibition can be relieved by (C) LD and LD (D) LD raising the 1 2 5 308. Enzymes which are always present in an (A) Enzyme concentration organism are known as (B) Substrate concentration (A) Inducible enzymes (C) Inhibitor concentration (B) Constitutive enzymes (D) None of these (C) Functional enzymes 300. Physostigmine is a competitive inhibitor (D) Apoenzymes of 309. Inactive precursors of enzymes are known (A) Xanthine oxidase as (B) Cholinesterase (A) Apoenzymes (B) Coenzymes (C) Carbonic anhydrase (C) Proenzymes (D) Holoenzymes (D) Monoamine oxidase 310. Whcih of the following is a proenzyme? 301. Carbonic anhydrase is competitively (A) Carboxypeptidase inhibited by (B) Aminopeptidase (A) Allopurinol (B) Acetazolamide (C) Chymotrypsin (C) Aminopterin (D) Neostigmine (D) Pepsinogen ENZYMES 159

311. Allosteric enzymes regulate the formation 321. Alkaline phosphatase is present in of products by (A) Liver (B) Bones (A) Feedback inhibition (C) Intestinal mucosa (D) All of these (B) Non-competitive inhibition (C) Competitive inhibition 322. All of the following are zinc-containing enzymes except (D) Repression-derepression (A) Acid Phosphatase 312 Regulation of some enzymes by covalent (B) Alkaline Phosphatase modification involves addition or removal of (C) Carbonic anhydrase (A) Acetate (B) Sulphate (D) RNA (C) Phosphate (D) Coenzyme 323. All of the following are iron-containing enzymes except 313. Covalent modification of an enzyme generally requires a (A) Carbonic anhydrase (A) Hormone (B) cAMP (B) Catalase (C) Protein kinase (D) All of these (C) Peroxidase (D) Cytochrome oxidase 314. An inorganic ion required for the activity of an enzyme is known as 324. Biotin is a coenzyme for (A) Activator (B) Cofactor (A) Pyruvate dehydrogenase (C) Coenzyme (D) None of these (B) Pyruvate carboxylase 315. The first enzyme found to have iso- (C) PEP carboxykinase enzymes was (D) Glutamate pyruvate transminase

(A) Alkaline Phosphatase 325. Enzymes accelerate the rate of reactions (B) Lactate dehydrogenase by (C) Acid Phosphatase (A) Increasing the equilibrium constant of reactions (D) Creatine kinase 316. Lactate dehydrogenase is located in (B) Increasing the energy of activation (A) Lysosomes (B) Mitochondria (C) Decreasing the energy of activation (C) Cytosol (D) Microsomes (D) Decreasing the free energy change of the reaction 317. Lactate dehydrogenase is a 326. Kinetics of an allosteric enzyme are (A) Monomer (B) Dimer explained by (C) Tetramer (D) Hexamer (A) Michaelis-Menten equation 318. Ceruloplasmin is absent in (B) Lineweaver-Burk plot (A) Cirrhosis of liver (B) Wilson’s disease (C) Hill plot (C) Menke’s disease (D) Copper deficiency (D) All of these

319. Ceruloplasmin oxidizes 327. Covalent modification of an enzyme (A) Copper (B) Iron usually involves phosphorylation / (C) Both (A) and (B) (D) None of these dephosphorylation of 320. Creatine kinase is present in all of the (A) Serine residue following except (B) Proline residue (A) Liver (B) Myocardium (C) Hydroxylysine residue (C) Muscles (D) Brain (D) Hydroxyproline residue 160 MCQs IN BIOCHEMISTRY

328. Vmax of an enzyme may be affected by 335. The highest energy level is present (A) pH amongst the following in (B) Temperature (A) 1, 3-Biphosphoglycerate (C) Non-competitive inhibitors (B) Creatine phosphate (D) All of these (C) Carbamoyl phosphate (D) Phosphoenol pyruvate 329. In enzyme assays, all the following are kept constant except 336. Daily urinary urobilinogen excretion in adult men is (A) Substrate concentration (A) 0–4 mg (B) 5–8 mg (B) Enzyme concentration (C) 9–12 mg (D) 13–20 mg (C) pH (D) Temperature 337. In obstructive jaundice, faecal urobilino- gen is 330. If the substrate concentration is much below the km of the enzyme, the velocity (A) Absent (B) Decreased of the reaction is (C) Increased (D) Normal (A) Directly proportional to substrate concentration 338. Acetyl-CoA can be formed from (B) Not affected by enzyme concentration (A) Pyruvate (B) Fatty acids

(C) Nearly equal to Vmax (C) ketone bodies (D) All of these (D) Inversely proportional to substrate concentration 339. Pyruvate is converted into acetyl-CoA by 331. Enzymes requiring NAD as co-substrate (A) Decarboxylation can be assayed by measuring change in (B) Dehydrogenation absorbance at (C) Oxidative decarboxylation (A) 210 nm (B) 290 nm (D) Oxidative deamination (C) 340 nm (D) 365 nm 340. Conversion of pyruvate into acetyl CoA 332. Different isoenzymes of an enzyme have is catalysed by the same (A) Pyruvate dehydrogenase (A) Amino acid sequence (B) Didrolipoyl acetyl transferase (B) Michaelis constant (C) Dihydrolipoyl dehydrogenase (C) Catalytic activity (D) All the 3 acting in concert (D) All of these 341. Pyruvate dehydrogenase complex is 333. From the pentapeptide, phe-ala-leu-lys- located in arg, phenylalanine residue is split off by (A) Cytosol (A) Trypsin (B) Chymotrypsin (B) Lysosomes (C) Aminopeptidase (D) Carboxypeptidase (C) Mitochondria (D) Endoplasmic reticulum 334. A high-energy phosphate among the following is 342. A flavoprotein in pyruvate dehydrogena- (A) Glucose-6-phosphate se complex is (B) Glucose-1-phosphate (A) Pyruvate dehydrogenase (C) 1, 3-Biphoglycerate (B) Didrolipoyl acetyl transferase (D) All of these (C) Dihydrolipoyl dehydrogenase (D) None of these ENZYMES 161

343. Pyruvate dehydrogenase complex is 352. All of the following are intermediates of regulated by citric acid cycle except (A) Covalent modification (A) Oxalosuccinate (B) Oxaloacetate (B) Allosteric regulation (C) Pyruvate (D) Fumarate (C) Both (A) and (B) 353. All of the following intermediates of citric (D) None of these acid cycle can be formed from amino acids 344. An allosteric inhibitor of pyruvate dehy- except drogenase is (A) α-Ketoglutarate (B) Fumarate (A) Acetyl CoA (B) ATP (C) Malate (D) Oxaloacetate (C) NADH (D) Pyruvate 354. Glycolytic pathway is located in 345. Ribozymes: (A) Mitochondria (B) Cytosol (A) RNA enzyme (B) Non-protein enzymes (C) Microsomes (D) Nucleus (C) Catalyst function (D) All of these 355. End product of aerobic glycolysis is 346. In citric acid cycle, NAD is reduced in (A) Acetyl CoA (B) Lactate (A) One reactions (B) Two reactions (C) Pyruvate (D) CO and H O (C) Three reactions (D) Four reactions 2 2 356. During fasting, glucose is phosphorylated 347. Among citric acid cycle enzymes, a flavo- mainly by protein is (A) Hexokinase (B) Glucokinase (A) Malate (C) Both (A) and (B) (D) None of these (B) Fumarase (C) Succinate dehrogenase 357. Glucokinase is found in (D) Isocitrate dehrogenase (A) Muscles (B) Brain 348. In citric acid cycle, GDP is phosphorylated (C) Liver (D) All of these by 358. In anaerobic glycolysis, energy yield (A) Succinate dehydrogenase from each molecule of glucose is (B) Aconitase (A) 2 ATP equivalents (B) 8 ATP equivalents (C) Succinate thiokinase (C) 30 ATP equivalents(D) 38 ATP equivalents (D) Fumarse 359. Which of the following is an allosteric 349. Malonate is an inhibitor of enzyme? (A) Malate dehydrogenase (A) Phosphohexose isomerase (B) α-Ketoglutarate dehydrogenase (B) Phosphotriose isomerase (C) Succinate dehydrogenase (C) Lactate dehydrogenase (D) Isocitrate dehydrogenase (D) Phosphofructokinase 350. Isocitrate dehydrogenase is allosterically 360. Glycolysis is anaerobic in inhibited by (A) Liver (B) Brain (A) Oxalosuccinate (B) α-Ketoglutarate (C) Kidneys (D) Erythrocytes (C) ATP (D) NADH 361. Phosphofructokinase is allosterically 351. All of the following are allosteric enzymes inhibited by except (A) Fructose-1, 6-biphosphate (A) Citrate synthetase (B) Lactate (B) a-Ketoglutarate dehdrogenase (C) Pyruvate (C) Succinate thiokinase (D) Citrate (D) Succinate dehydrogenase 162 MCQs IN BIOCHEMISTRY

362. Glucose-6-phosphate is an allosteric 370. Glucose-6-phosphate dehydrogenase is inhibitor of induced by (A) Glucokinase (A) 6-Phosphogluconolactone (B) Hexokinase (B) Glucose-6-phosphate (C) Phosphohexose isomerase (C) Ribose-5-phosphate (D) None of these (D) Insulin 363. ATP is a co-substrate as well as an allos- 371. The decarboxylation reaction in HMP teric inhibitor of shunt is catalysed by (A) Phosphofructokinase (A) Gluconolactone hydrolase (B) Hexokinase (B) 6-Phosphogluconate dehydrogenase (C) Glucokinase (C) 6-Phosphogluconate decarboxylase (D) None of these (D) 364. Complete oxidation of one molecule of 372. The first pentose formed in HMP shunt is glucose into CO2 and H2O yields (A) 8 ATP equivalents (A) Ribose-5-phosphate (B) Ribulose-5-phosphate (B) 15 ATP equivalents (C) Xylose-5-phosphate (D) Xylulose-5-phosphate (C) 30 ATP equivalents 373. The regulatory enzyme in HMP shunt is (D) 38 ATP equivalents (A) Glucose-6-phosphate dehydrogenase 365. A unique by-product of glycolysis in (B) 6-Phosphogluconate dehydrogenase erythrocytes is (C) Both (A) and (B) (A) Lactate (D) None of these (B) 1, 3-Biphosphoglycerate (C) 2, 3-Biphosphoglycerate 374. The rate of HMP shunt reactions is (D) All of these (A) Increased by Insulin (B) Increased in diabetes mellitus 366. Which of the following enzymes incorpo- rates inorganic phosphate into the sub- (C) Increased by glucagons strate? (D) Increased in starvation (A) Phosphoglycerate kinase 375. Glycogenesis requires (B) Glyceraldehyde-3-phosphate dehydrogenase (A) GTP (B) CTP (C) Pyruvate kinase (C) UTP (D) None of these (D) Enolase 376. Glycogen synthetase catalyses the 367. Rapoport-Luebering cycle is located in formation of (A) Liver (B) Muscles (A) α−1, 4-Glycosidic bonds (C) Brain (D) Erythrocytes (B) α−1, 6-Glycosidic bonds 368. Glycerol can enter glycolytic pathway via (C) Both (A) and (B) (D) None of these (A) Dihydroxyacetone phosphate (B) 1, 3-Biphospoglycerate 377. Glycogenoloysis is increased by (C) 3-Phosphoglycerate (A) Glucagon (B) Insulin (D) 2-Phosphoglycerate (C) Epinephrine (D) cAMP 369. HMP shunt is present in 378. Hepatic glycogenoloysis is increased by (A) Erythrocytes (B) Liver (A) Insulin (B) Glucagon (C) Testes (D) All of these (C) Epinephrine (D) Glucocorticoids ENZYMES 163

379. Glycogen phosphorylase liberates the 388. Gluconeogenesis does not occur in following from glycogen (A) Brain (B) Kidneys (A) Glucose (C) Muscles (D) Liver (B) Glucose-6-phosphate 389. Glucose cannot be synthesized from (C) Glucose-1-phosphate (A) Glycerol (B) Lactate (D) Maltose (C) Alanine (D) Leucine 380. After the action of phosphorylase, glyco- gen is converted into 390. Coenzyme for phosphoenolpyruvate carboxykinase is (A) Amylopectin (B) dextrin (A) ATP (B) ADP (C) Amylose (D) Maltose (C) GTP (D)GDP 381. Glucose-1-phosphate liberated from glycogen cannot be converted into free 391. Therapeutic enzymes: glucose in (A) Streptokinase (B) (A) Liver (B) Kidneys (C) Riboflavinase (D) Both (A) and (B) (C) Muscles (D) Brain 392. A gluconeogenic enzyme among the 382. A coenzyme present in phosphorylase is following is (A) NAD (A) Phosphofructokinase (B) Pyridoxal phosphate (B) Pyruvate kinase (C) Thiamin pyrophosphate (C) Phosphoenol pyruvate carboxykinase (D) Coenzyme A (D) Glucokinase 383. If glucose-1-phosphate formed by 393. Glucose-6-phosphatase and PEP carboxy glycogenoloysis in muscles is oxidized to kinase are regulated by

CO2 and H2O, the energy yield will be (A) Covalent modification (A) 2 ATP equivalents (B) 3 ATP equivalents (B) Allosteric regulation (C) 4 ATP equivalents (D) 8 ATP equivalents (C) Induction and repression (D) All of these 384. A molecule of phosphorylase kinase is made up of 394. The maximum possible chain length of (A) 4 subunits (B) 8 subunits fatty acids formed in the pathway of de novo synthesis is (C) 12 subunits (D) 16 subunits (A) 16 Carbon atoms (B) 18 Carbon atoms 385. Cyclic AMP binds to (C) 20 Carbon atoms (D) 24 Carbon atoms (A) Catalytic subunits of protein kinase 395. Acetyl CoA required for de novo synthesis (B) Regulatory subunits of protein kinase of fatty acids is obtained from (C) Catalytic subunits of phosphorylase kinase (A) Breakdown of existing fatty acids (D) Regulatory subunits of phosphorylase kinase (B) Ketone bodies 386. Glucose is the only source of energy for (C) Acetate (A) Myocardium (B) Kidneys (D) Pyruvate (C) Erythrocytes (D) Thrombocytes 396. Formation of acetyl CoA from pyruvate 387. Glycerol-3-phosphate for the synthesis of for de novo synthesis of fatty acids requires triglycerides in adipose tissue is derived (A) Pyruvate dehydrogenase complex from (B) Citrate synthetase (A) Phosphatidic acid (B) Diacylglycerol (C) ATP citrate lyase (C) Glycerol (D) Glucose (D) All of these 164 MCQs IN BIOCHEMISTRY

397. The major site for elongation of medium 405. Which one of the following cofactors must chain fatty acids is be utilized during the conversion of acetyl (A) Mitochondria (B) Cytosol CoA to malonyl CoA? (C) Microsomes (D) All of these (A) TPP (B) ACP (C) NAD+ (D) Biotin 398. βββ-oxidation of fatty acids is inhibited by (A) NADPH (B) Acetyl CoA 406. Which one of the following enzymes (C) Malonyl CoA (D) None of these requires a coenzyme derived from the vitamin whose structure is shown below? 399. The enzyme regulating extramitochondri- al fatty acid synthesis is (A) Enoyl CoA hydratase (B) Phosphofructokinase (A) Thioesterase (C) Glucose-6-phosphatase (B) Acetyl CoA carboxylase (D) Glucose-6-phosphate dehydrogenase (C) Acyl transferase (D) Multi-enzyme complex 407. Coenzymes derived from the vitamin shown below are required by enzymes 400. Acetyl CoA carboxylase is activated by involved in the synthesis of which of the (A) Citrate (B) Insulin following? (C) Both (A) and (B) (D) None of these (A) ATP (B) UTP 401. All the following statements about acetyl (C)CTP (D) NADH CoA carboxylase are true except: 408. Coenzymes derived from the vitamin (A) It is activated by citrate shown below are required by which of (B) It is inhibited by palmitoyl CoA the following enzymes? (C) It can undergo covalent modification (A) Lactate dehydrogenase (D) Its dephosphorylated form is inactive (B) Glutamate dehydrogenase 402. All the following statements about acetyl (C) Pyruvate dehydrogenase CoA carboxylase are true except (D) Malate dehydrogenase (A) It is required for de novo synthesis of fatty 409. All the following are coenzymes except acids (A) Ubiquinone (B) It is required for mitochondrial elongation of fatty acids (B) CoA (C) It is required for microsomal elongation of fatty (C) Pyruvate dehydrogenase acids (D) Lipoic acid (D) Insulin converts its inactive form into its active 410. Which of the following is not a cofactor? form (A) Mg (B) Iron 403. Both Acyl carrier protein (ACP) of fatty (C) Cu (D) Methylcobalamine acid synthetase and coenzyme (CoA) are 411. All the following compounds are (A) Contain reactive phosphorylated members of the electron transport chain (B) Contain thymidine except (C) Contain phosphopantetheine reactive groups (A) Ubiquinone (B) Carnitine (D) Contain cystine reactive groups (C) NAD (D) FAD 404. Which one of the following transfers acyl 412. Thiamine is essential for groups? (A) Pyruvate dehydrogenase (A) Thiamine pyrophosphate (B) Isocitrate dehydrogenase (B) Lipomide (C) Succinate dehydrogenase (C) ATP (D) Acetyl CoA synthetase (D) NADH ENZYMES 165

413. Adenylate cyclase is activated by 422. A substrate for the enzyme aldolase is (A) Insulin (B) Glucagon (A) galactose-6-phosphate 2+ (C) Prostaglandin E1 (D) Ca ions (B) isocitric acid (C) Glucose-1-phosphate 414. Maximum enzyme activity is observed at (D) Fructose 1, 6 diphosphate (A) Acidic pH (B) Neutral pH (C) Basic pH (D) Optimum pH 423. Decarboxylation of ααα-keto acids requires (A) Thiamine pyrophosphate, FAD, NAD+ 415. Which of the following is known as bone forming enzyme? (B) Flavin mononucleotide (C) NADP+ (A) Alkaline phosphatase (D) NAD+ only (B) Acid phosphatase (C) Leucine aminopeptidase 424. Coenzyme A contains the vitamin: (D) γ-glutamyl transpeptidase (A) Riboflavin (B) Pantothenic acid 416. Conversion of pepsinogen to pepsin is (C) Pyridoxine (D) Thiamine (A) Intra molecular rearrangement 425. Which of the following is not a component (B) Breaking of hydrogen bonds of coenzyme A? (C) Covalent modification (A) Adenylic acid (D) Polymerisation (B) Pantothenic acid (C) β -mercaptoethylamine 417. Which of the following is not having an apoenzyme and coenzyme? (D) Deoxyadenylic acid (A) Lactate dehydrogenase 426. Malic enzyme convers malic acid, in the + (B) Succinate dehydrogenase presence of NADP to Pyruvic acid. This reaction is a/an (C) Malate dehydrogenase (D) Pepsin (A) Decarboxylation (B) Decarboxylation and Dehydrogenation 418. Pyruvate dehydrogenase is a/an (C) Dehydrogenation (A) Isomerase (B) Lyase (D) Oxidation (C) Ligase (D) Oxido reductase 427. The following reaction is characteristic of 419. Homogentisic oxidase is an what type of enzymes?

(A) Oxidase 2H2O2 →→→ 2H2O + O2 (B) Monooxygenase (A) Peroxides (C) Dioxygenase (B) Catalase (D) Anaerotic dehydrogenase (C) Dehydrogenase 420. Isocitrate dehydrogenase can use (D) Copper containing oxidases ______as a cofactor. 428. Of Which warburg’s yellow enzyme (A) NAD+ only (B) NADP+ only contains as a prosthetic group? (C) NAD+ or NADP+ (D) FMN and FAD (A) Thiamine pyrophosphate 421. The rate of most enzyme catalysed (B) Biotin reactions changes with pH. As the pH (C) NAD+ increases, this rate (D) Riboflavin-5-phosphate (A) reaches a minimum, then increases 429. Dehydrogenases utilize, as coenzymes, all (B) reaches a maximum, then decreases of the following except (C) increases (A) NAD+ (B) NADP+

(D) decreases (C) FAD (D) FH4 166 MCQs IN BIOCHEMISTRY

430. Urea is produced physiologically by the 438. Immobilized enzymes: action of the enzyme: (A) Potentiation of activity (A) (B) Glutaminase (B) Presentation of activity (C) Arginase (D) None of these (C) Preparation of activity 431. Urease is a (D) All of these (A) Lyase (B) Ligase 439. This catalyzes formation of CoA deriva- (C) Isomerase (D) Hydrolase tives from fatty acid, CoA and ATP: (A) Acyl CoA dehydrogenase 432. Velocity maximum for an enzyme at half the substrate concentration gives (B) Enoyl hydrase (C) β-OH acyl CoA dehydrogenase (A) The molecular weight of the enzyme (D) Thio kinase (B) Km value (C) Isoelectric pH 440. Fructose 2, 3 bi phosphate is a powerful (D) Pk value allosteric activator of (A) Fructose 1, 6 diphosphatase 433. Which of the following amino acid has (B) Phosphofructokinase been shown as one of the active site of phosphoglucomutase? (C) Hexokinase (D) Fructokinase (A) Lysine (B) Tyrosine (C) Serine (D) Histidine 441. ‘Clearing factor’ is 434. The inhibition of succinate dehydro- (A) Lipoprotein lipase genase by malonate by (B) Crotonase (A) Competitive inhibition (C) 7-dehydro cholesterol (B) Non-competitive inhibition (D) β-sitosterol (C) Uncompetitive inhibition 442. Maltase attacks only (D) Feedback inhibition (A) α-glucosides (B) β-glucosides 435. Cobamide coenzymes are (C) Starch (D) Dextrins

(A) Vitamin B1 (B) Riboflavin 443. Pepsin is (C) Pyridoxine (D) Vitamin B12 (A) Exo-peptidase (B) Endo-peptidase 436. The isozyme CK-MB is specifically (C) Carboxy peptidase(D) Amino peptidase increased in the blood of patients who 444. An enzyme in saliva which hydrolyzes had starch is (A) Skeletal muscle disease (A) Pepsinogen (B) Chymotrysin (B) Recent myocardial infarction (C) α-Amylase (D) Malate (C) Infective hepatitis (D) Myxoedema 445. If a coenzyme is required in an enzyme reaction, the former usually has the 437. FAD containing enzyme, catalyzing function of formation of ααα, βββ unsaturated fatty acyl (A) Acting as an acceptor for one of the cleavage CoA derivative. products of the substrate (A) Acyl CoA dehydrogenase (B) Enhancing the specificity of the apo enzyme (B) Enoyl hydrase (C) Increasing the number of receptor sites of the (C) β-OH acyl CoA dehydrogenase apo enzyme (D) Thiolase (D) Activating the substrate ENZYMES 167

446. The Michaehis-Menten hypothesis: (B) Changing the specificity of the enzyme for (A) Postulates the formation of an enzyme the substrate substrate complex (C) Changing the conformation of the enzyme by binding to a site other than catalytic site (B) Enables us to calculate the isoelectric point of an enzyme (D) Changing the nature of the products formed (C) States that the rate of a chemical reaction may 454. Which of the following regulatory be independent of substrate concentration reactions involves a reversible covalent (D) States that the reaction rate is proportional to modification of an enzyme? substrate concentration (A) Phosphorylation of serine OH on the enzyme 447. Schardinger’s enzyme is (B) Allosteric modulation (C) Competitive inhibition (A) Lactate dehydrogenase (D) Non-competitive inhibition (B) (C) Uric oxidase 455. A competitive inhibitor of an enzyme has (D) L amino acid dehydrogenase which of the following properties? (A) It is frequently a feedback inhibitor 448. Tryptophan pyrolase is currently known (B) It becomes covalently attached to an enzyme as (C) It decreases the V (A) Tryptophan deaminase max (D) It interferes with substrate binding to the (B) Tryptophan dioxygenase enzyme (C) Tryptophan mono oxygenase 456. When [s] is equal to K , which of the (D) Tryptophan decarboxylase m following conditions exist? 449. An enzyme which brings about lysis of (A) Half the enzyme molecules are bound to bacterial cell wall is substrate (A) Amylase (B) (B) The velocity of the reaction is equal to Vmax (C) Trypsin (D) Lipase (C) The velocity of the reaction is independent of substrate concentration 450. Trypsin has no action on (D) Enzyme is completely saturated with substrate (A) Hemoglobin (B) Albumin 457. Which of the following statements about (C) Histone (D) DNA an enzyme exhibiting allosteric kinetics 451. Multiple forms of the same enzymes are with cooperative interaction is false? known as (A) A plot of V-Vk [s] has a sigmaidal shape

(A) Zymogens (B) Isoenzymes (B) An inhibitor may increase the apparent Km (C) Proenzymes (D) Pre-enzymes (C) Line weaver Bnrk plot is useful for determining Km and Vmax 452. In non-competitive enzyme action (D) Removal of allosteric inhibitor may result in

(A) Vmax is increased hyperbolic V-S [s] plot (B) Apparent k is increased m 458. Pantothenic acid acts on (C) Apparent k is decreased m (A) NADP (B) NADPH (D) Concentration of active enzyme molecule is (C) FAD (D) CoA reduced 459. Vitamin deficiency that causes fatty liver 453. An allosteric enzyme influences the includes all except enzyme activity by (A) Vitamin E (B) Pyridoxine (A) Competiting for the catalytic site with the (C) Retionic acid (D) Pantothenic acid substrate 168 MCQs IN BIOCHEMISTRY

460. In which of the following types of 467. The best test for acute pancreatitis in the enzymes an inducer is not required? presence of mumps is (A) Inhibited enzyme (B) Cooperative enzyme (A) A serological test for mumps (C) Allosteric enzyme (D) Constitutive enzyme (B) Serum amylase (C) Urinary amylase 461. In which of the following types of enzyme water may be added to a C—C double (D) Serum lipase bond without breaking the bond? 468. The slow moving fraction of LDH is (A) Hydrolase (B) Hydratase typically increased in pancreas with (C) Hydroxylase (D) Esterase (A) Cerebrovascular accidents 462. ‘Lock’ and ‘Key’ model of enzyme action (B) Acute myocardial infarction proposed by Fisher implies that (C) Acute pancreatitis (D) Acute viral hepatits (A) The active site is flexible and adjusts to substrate 469. Which of the following enzyme typically

(B) The active site requires removal of PO4 group elevated in alcoholism? (C) The active site is complementary in shape to (A) Serum ALP that of the substrate (B) Serum GOT (D) Substrates change conformation prior to active (C) Serum γ-GT site interaction (D) Serum acid phosphatase 463. In competitive inhibition of enzyme action 470. Patients with hepatocellular jaundice, as

(A) The apparent Km is decreased compared to those with purely obstruc- tive jaundice tend to have (B) The apparent Km is increased

(C) Vmax is decreased (A) Lower serum ALP, LDH and AST activity (D) Apparent concentration of enzyme molecules (B) Lower serum ALP, Higher LDH and AST activity decreased (C) Higher serum ALP, LDH and AST activity 464. In competitive inhibition which of the (D) Higher serum ALP, Lower LDH and AST activity following kinetic effect is true ? 471. If results of the serum bilirubin, serum ALP,

(A) Decreases both Km and Vmax LDH and AST determinations suggest (B) Increases both K and V obstructive jaundice, the best confirmatory m max test would be the estimation of (C) Decreases Km without affecting Vmax (A) Serum ALT (D) Increases Km without affecting Vmax (B) Serum 5’ 465. Enzymes increase the rates of reactions (C) Serum Pseudo cholinesterase by (D) None of these (A) Increasing the free energy of activation (B) Decreasing the energy of activation 472. Which enzyme estimation will be helpful in differentiating the elevated serum ALP (C) Changing the equilibrium constant of the found in obstructive jaundice as well as reaction bone disorders? (D) Increasing the free energy change of the (A) Serum AST (B) Serum ALT reaction (C) Serum LDH (D) Serum γ-GT 466. The most useful test for the diagnosis of acute hemorrhagic pancreatitis during 473. Cardiac muscle contains which of the the first few days is following CK osoenzyme? (A) Urinary lipase test (B) Serum calcium (A) BB only (B) MM and BB only (C) Urinary amylase (D) Serum amylase (C) MM, BB and MB (D) MM and MB only ENZYMES 169

474. Liver and skeletol measle disorders are 482. Diastase can be used for the hydrolysis characterized by on disk proportionate can be used for the hydrolysis of increase in which of the LDH isoenzyme fraction? (A) Sucrose (B) Starch (C) Cellulose (D) Maltose (A) LDH-1 (B) LDH-1 and LDH-2 (C) LDH-3 and LDH-4 (D) LDH-2 and LDH-3 483. Which of the following statements is true? (E) LDH-5 (A) Enzymes have names ending ase 475. On the third day following onset of acute (B) Enzymes are highly specific in their action myocardial infarction, which enzyme (C) Enzymes are living organisms estimation will have the best predictive value? (D) Enzymes get activated on heating (A) Serum AST (B) Serum CK 484. Enzymes activity is controlled by (C) Serum ALT (D) Serum LDH (A) pH of the solution 476. Serum AST activity is not characteristically (B) Temperature elevated as the result of (C) Concentration of the enzyme (A) Myocardial infarction (D) Concentration of the substrate (B) Passive congestion of liver (E) All of these (C) Muscular dystrophies 485. Which of the following is not true regard- (D) Peptic ulcer ing enzymes? 477. On which day following acute myocardial (A) They catalyze only a particular type of reaction infarction the estimation of serum AST will be of greatest significance? (B) They remain active even after separation from the source (A) First day (B) Second day (C) Third day (D) Fourth day (C) They are destroyed after the completion of the reaction they catalyse 478. In which diseases of the following organs, (D) They are irreversibly destroyed at high isoenzymes LDH-1 and LDH-2 will be temperature released in plasma? (E) Their activity depends on the pH of the solution (A) Kidney, R.B.C and Liver (B) Heart, Kidney and R.B.C 486 The number of enzymes known is about (C) Heart, Kidney and Liver (A) 10,000 (B) 100 (D) Heart, Lungs and Brain (C) 50 (D) 26 479. Plasma non-functional enzymes are 487. Nicotine present in tobacco is a/an (A) totally absent (A) Alkaloid (B) Terpene (B) low concentration in plastic (C) Steroid (D) Protein (C) important for diagnosis of several disease (D) All of these 488. The poisonous alkaloid present in the oil of hemlock is 480. Pyruvate dehydrogenase contains all except (A) Cocaine (B) Nicotine (A) Biotin (B)NAD (C) Quinine (D) Morphine (C) FAD (D) CoA 489. Alkaloids are usually purified by extrac- 481. An increase in LDH-5 enzyme is seen in tion with the following except (A) Ether (B) Dil HCl (A) Acute hepatitis (B) Muscular distrophies (C) NaOH (D) Chloroform (C) Breast carcinoma (D) Pulmonary embolism 170 MCQs IN BIOCHEMISTRY

490. The number of N-MC groups in alkaloids (D) Be localized intracellularly is best estimate with the help of (E) Be a catalyst (A) HI (B) H SO 2 4 497. LDH assays are most useful in diagnosing (C) (CH3CO)2 CO (D) CH3 Mg I diseases of the 491. A competitive inhibitor of an enzyme (A) Heart (B) Pancreas

(A) Increases Km without affecting Vmax (C) Brain (D) Kidney (B) Decreases K without affecting V m max 498. The chemical forces that bind most (C) Increases Vmax without affecting Km coenzymes and substrates to enzymes (D) Decreases both Vmax and Km such as LDH are

492. The Michaelis constant, Km is (A) Hydrogen bonds (B) Peptide bonds (C) Coordinate bonds (D) Covalent bonds (A) Numerically equal to ½ Vmax (B) Dependent on the enzyme concentration 499. How many different proteins may be (C) Independent of pH present in normal LDH? (D) Numerically equal to the substrate concen- (A) One (B) Two tration that gives half maximal velocity (C) Three (D) Four 493. The rate of an enzyme catalyzed reaction was measured using several substrate 500. All the isoenzymes function with the concentrations that were much lower coenzyme: + than Km, the dependence of reaction (A) NADP (B) FAD velocity on substrate concentration can (C) Lipoate (D) NAD+ best be described as 501. ‘Lock’ and ‘Key’ theory was proposed by (A) Independent of enzyme concentration (A) Sorenson (B) Fischer (B) A constant fraction of Vmax (C) Mehler (D) Sanger (C) Equal to Km (D) Proportional to the substrate concentration 502. Which of the following forms part of a 494. The presence of a non competitive inhibitor coenzyme? (A) Zn2+ (B) Lipase (A) Leads to both an increase in the Vmax of a reaction and an increase in Km (C) Vitamin B2 (D) Lysine (B) Leads to a decrease in the observed Vmax 503. The shape of an enzyme and conse- (C) Leads to a decrease in Km and Vmax quently its activity can be reversibly (D) Leads to an increase in Km without affecting altered from moment to moment by V max (A) Heat (B) Amino acid substrate 495. Which one of the following statements is (C) Allosteric subunits (D) Sulfur substitutions not characteristic of allosteric enzymes? 504. Which one of the following regulatory (A) They frequently catalyze a committed step actions involves a reversible covalent early in a metabolic pathway modification of the enzyme? (B) They are often composed of subunits (C) They follow Michaelis-Menten kinetics (A) Phosphorylation of ser-OH on the enzyme (D) They frequently show for (B) Allosteric modulation substrate binding (C) Competitive inhibition (D) Non-competitive inhibition 496. The abnormal isoenzyme need not (A) Be an oxidoreductase 505. An enzyme is a (B) Have any coenzyme (A) Carbohydrate (B) Lipid (C) Require ATP (C) Protein (D) Nucleic acid ENZYMES 171

506. An enzyme promotes a chemical reaction (C) Carboxyl group of the amino acids by (D) Exposed sulfur bonds (A) Lowering the energy of activation 513. Allosteric enzymes contain (B) Causing the release of heat which acts as a (A) Multiple subunits (B) Single chain primer (C) Two chains (D) Three chains (C) Increasing molecular motion (D) Changing the free energy difference between 514. Isoenzymes of lactate dehydrogenase are substrate and product useful for the diagnosis of (A) Heart disease (B) Kidney disease 507. In most metabolic pathways, all needed enzymes are arranged together in a (C) Liver disease (D) Both (A) and (C) multienzyme complex within a 515. IUB had divided enzymes into how many (A) Solution of ATP classes? (B) Membrane (A) 6 (B) 5 (C) Quanternary protein (C) 8 (D) 4 (D) Coenzyme 516. The first enzyme isolated, purified and 508. An enzyme catalyzes the conversion of an crystallied from Jack bean (Canavalia) by aldose sugar to a ketose sugar would be summer in 1926 was classified as one of the (A) Urease (B) Insulin (A) (B) (C) (D) Zymase (C) Oxido (D) Hydrolases 517. Who suggested that enzymes are protein- aceous? 509. The function of an enzyme is to (A) Buchner (B) Kuhne (A) Cause chemical reactions that would not otherwise take place (C) Sumner (D) Pasteur (B) Change the rates of chemical reactions 518. Feedback inhibition of enzyme action is (C) Control the equilibrium points of reactions affected by (D) Change the directions of reactions (A) Enzyme (B) Substrate (C) End products (D) None of these 510. In which of the following types of enzymes, water may be added to a C—C 519. The enzyme that converts glucose to double bond without breaking the bond? glucose-6-phosphate is (A) Hydrolase (B) Hydratase (A) Phosphatase (B) Hexokinase (C) Hydroxylase (D) Oxygenase (C) Phosphorylase (D) Glucose synthetase 511. Enzymes increases the rate of reactions 520. Enzymes are required in traces because by they (A) Increasing the free energy of activation (A) Have high turnover number (B) Decreasing the energy of activation (B) Remain unused at the end of reaction and (C) Changing the equilibrium constant of the are re used reaction (C) Show cascade effect (D) Increasing the free energy change of the (D) All correct reaction 521. An organic substance bound to an 512. The active site of an enzyme is formed by enzyme and essential for the activity of a few of the enzymes: enzyme is called (A) R groups of the amino acids (A) Holoenzyme (B) Apoenzyme (B) Amino groups of the amino acids (C) Coenzyme (D) Isoenzyme 172 MCQs IN BIOCHEMISTRY

522. Enzyme catalysed reactions occur in (C) Dry seeds have more reserve food (A) Pico seconds (B) Micro seconds (D) Seedlings are tender (C) Milli seconds (D) None of these 531. Coenzymes FMN and FAD are derived 523. An enzyme can accelerate a reaction up to from vitamin 10 1 (A) 10 times (B) 10 times (A) C (B) B6 100 (C) 10 times (D) 10 times (C) B1 (D) B2 524. In plants, enzymes occur in 532. Template/lock and key theory of enzyme action is supported by (A) Flowers only (B) Leaves only (C) All living cells (D) Storage organs only (A) Enzymes speed up reaction (B) Enzymes occur in living beings and speed 525. Zymogen is a up certain reactions (A) Vitamin (B) Enzyme precursor (C) Enzymes determine the direction of reaction (C) Modulator (D) Hormone (D) Compounds similar to substrate inhibit enzyme activity 526. Cofactor (Prosthetic group) is a part of holoenzyme, it is 533. Combination of apoenzyme and (A) Inorganic part loosely attached coenzyme produces (B) Accessory non-protein substance attached (A) Prosthetic group firmly (B) Holoenzyme (C) Organic part attached loosely (C) Enzyme substrate complex (D) None of these (D) Enzyme product complex 527. A protein having both structural and 534. Enzyme inhibition caused by a substance enzymatic traits is resembling substrate molecule is (A) Myosin (B) Collagen (A) Competitive inhibition (C) Trypsin (D) Actin (B) Non-competitive inhibition 528. Enzymes are different from catalysts in (C) Feedback inhibition (A) Being proteinaceous (D) Allosteric inhibition (B) Not used up in reaction 535. An enzyme brings about (C) Functional at high temperature (A) Decrease in reaction time (D) Having high rate of diffusion (B) Increase in reaction time 529. Enzymes, vitamins and hormones are (C) Increase in activation energy common in (D) Reduction in activation energy (A) Being proteinaceous 536. Feedback inhibition of enzyme is influen- (B) Being synthesized in the body of organisms ced by (C) Enhancing oxidative metabolism (A) Enzyme (B) External factors (D) Regulating metabolism (C) End product (D) Substrate 530. Dry seeds endure higher temperature 537. Coenzyme is than germinating seeds as (A) Often a vitamin (B) Always an inorganic (A) Hydration is essential for making enzymes compound sensitive to temperature (C) Always a protein (D) Often a metal (B) Dry seeds have a hard covering ENZYMES 173

538. Genetic engineering requires enzyme: 545. Vitamin B2 is component of coenzyme: (A) DNA ase (A) Pyridoxal phosphate (B) Amylase (B) TPP (C) Lipase (C) NAD (D) Restriction (D) FMN/FAD

539. Which is not true about inorganic cata- 546. Km value of enzyme is substrate concen- lysts and enzymes? tration at

(A) They are specific (A) ½ Vmax (B) 2 Vmax

(B) Inorganic catalysts require specific not (C) ½ Vmax (D) 4 Vmax needed by enzymes 547. Part of enzyme which combines with non- (C) They are sensitive to pH protein part to form functional enzyme is (D) They speed up the rate of chemical reaction (A) Apoenzyme (B) Coenzyme 540. Key and lock hypothesis of enzyme action (C) Prosthetic group (D) None of these was given by 548. Who got Nobel Prize in 1978 for working (A) Fischer (B) Koshland on enzymes? (C) Buchner (D) Kuhne (A) Koshland (B) Arber and Nathans 541. An example of feedback inhibition is (C) Nass and Nass (D) H.G. Khorana (A) Allosteric inhibition of hexokinase by glucose- 549. Site of enzyme synthesis in a cell is 6-phosphate (A) Ribosomes (B) RER (B) Cyanide action on cytochrome (C) Golgi bodies (D) All of these (C) Sulpha drug on folic acid synthesizer bacteria 550. The fruit when kept is open, tastes bitter (D) Reaction between succinic dehydrogenase after 2 hours because of and succinic acid (A) Loss of water from juice 542. Feedback term refers to (B) Decreased concentration of fructose in juice (A) Effect of substrate on rate of enzymatic (C) Fermentation by yeast reaction (D) Contamination by bacterial enzymes (B) Effect of end product on rate reaction 551. Hexokinase (Glucose + ATP →→→ Glucose-6– (C) Effect of enzyme concentration on rate of P + ADP) belongs to the category: reaction (A) Transferases (B) Lysases (D) Effect of external compound on rate of (C) Oxidoreductases (D) Isomerases reaction 552. Which enzyme is concerned with transfer 543. Allosteric inhibition of electrons? (A) Makes active site unifit for substrate (A) Desmolase (B) Hydrolase (B) Controls excess formation and end product (C) Dehydrogenase (D) Transaminase (C) Both (A) and (B) (D) None of these 553. The best example of extracellular enzymes (exoenzyme) is 544. The ratio of enzyme to substrate mole- (A) cules can be as low as (B) Digestive enzymes (A) 1 : 100,000 (B) 1 : 500,000 (C) Succinic dehydrogenase (C) 1 : 10,000 (D) 1 : 1,000 (D) None of these 174 MCQs IN BIOCHEMISTRY

554. Which mineral element controls the (B) NH2 group of amino acids activity of ? (C) CO group of amino acids (A) Fe (B) Mo (D) Sulphur bonds which are exposed (C) Zn (D) Ca 563. Carbonic anhydrase enzyme has maxi- 555. Name the enzyme that acts both as mum turn over number (36 million). Min- carboxylase at one time and oxygenase imum turn over number for an enzyme: at another time. (A) DNA polymerase (A) PEP carboxylase (B) RuBP carboxylase (B) Lysozyme (C) Carbonic anyhdrase (C) Penicillase (D) None of these (D) Lactase dehydrogenase 556. A metabolic pathways is a 564. In cell, digestive enzymes are found (A) Route taken by chemicals mainly in (B) Sequence of enzyme facilitated chemical (A) Vacuoles (B) Lysosomes reactions (C) Ribosomes (D) Lomasomes (C) Route taken by an enzyme from one reaction to another 565. Substrate concentration at which an (D) Sequence of origin of organic molecules enzyme attains half its maximum velocity is 557. The energy required to start an enzymatic reaction is called (A) Threshold value (A) Chemical energy (B) Metabolic energy (B) Michaelis-Menton constant (C) Activation energy (D) Potential energy (C) Concentration level 558. Out of the total enzymes present in a cell, (D) None of these a mitochondrion alone has 566. Which enzyme hydrolyses starch? (A) 4% (B) 70% (A) (B) Maltase (C) 95% (D) 50% (C) Sucrase (D) Diastase 559. Creatine phosphokinase isoenzyme is a marker for 567. Enzymes functional in cell or mitochondria are (A) Kidney disease (B) Liver disease (A) Endoenzymes (B) Exoenzymes (C) Myocardial infarction (C) Apoenzymes (D) Holoenzymes (D) None of these 568. The enzymes present in the membrane of 560. Which inactivates an enzyme by occu- mitochondria are pying its active site? (A) Flavoproteins and cytochromes (A) Competitive inhibitor (B) Fumarase and lipase (B) Allosteric inhibitor (C) Enolase and catalase (C) Non-competitive inhibitor (D) Hexokinase and zymase (D) All of these 569. A mitochondrial marker enzyme is 561. Which one is coenzyme? (A) Aldolase (A) ATP (B) Vitamin B and C (B) Amylase (C) CoQ and CoA (D) All of these (C) Succinic dehydrogenase 562. The active site of an enzyme is formed by (D) Pyruvate dehydrogenase (A) R group of amino acids ENZYMES 175

570. The enzyme used in polymerase chain 579. Transaminase activity needs the Co- reaction (PCR) is enzyme:

(A) Taq polymerase (B) RNA polymerase (A) ATP (B) B6-PO4 (C) Ribonuclease (D) Endonuclease (C) FADT (D)NAD+

571. Which of the following is a microsomal en- 580. The biosynthesis of urea occurs mainly in zyme inducer? the liver: (A) Indomethacin (B) Clofibrate (A) Cytosol (B) Mitochondria (C) Tolbutamide (D) Glutethamide (C) Microsomes (D) Nuclei

572. Identify the correct molecule which 581. Bile salts make emulsification with fat for controls the biosynthesis of proteins in the action of living organisms. (A) Amylose (B) Lipase (A) DNA (B) RNA (C) Pepsin (D) Trypsin (C) Purines (D) Pyrimidines 582. All of the following compounds are 573. The tear secretion contains an antibac- intermediates of TCA cycle except terial enzyme known as (A) Maleate (B) Pyruvate (A) Zymase (B) Diastase (C) Oxaloacetate (D) Fumarate (C) Lysozyme (D) Lipase 583. In conversion of lactic acid to glucose, 574. Identify one of the canbonic anhydrase three reactions of glycolytic pathway are inhibitor that inhibit only luminal circumvented, which of the following carbonic anhydrase enzyme. enzymes do not participate? (A) Methazolamide (B) Acetazolamide (A) Pyruvate carboxylase (C) Dichlorphenamide (D) Benzolamide (B) Phosphoenol pyruvate carboxy kinase

575. Group transferring Co-enzyme is (C) Pyruvate kinase (D) Glucose-6-phosphatase (A) CoA (B) NAD+ (C) NADP+ (D) FAD+ 584. In the normal resting state of human most of the blood glucose burnt as fuel is 576. The co-enzyme containing an automatic consumed by hetero ring in the structure is (A) Liver (B) Brain (A) Biotin (B)TPP (C) Adipose tissue (D) Muscles (C) Sugar Phosphate (D) Co-enzyme 585. A regulator of the enzyme glucogen 577. The example of hydrogen transferring synthase is Co-enzyme is: (A) Citric Acid (B) Pyruvate + (A) B6-PO4 (B) NADP (C) Glucose-6-PO4 (D) GTP (C) TPP (D) ATP 586. A specific inhibitor for succinate dehydro- 578. Enzyme catalyzed hydrolysis of proteins genase is produces amino acid of the form (A) Arsenite (B) Malonate (A) D (B) DL (C) Citrate (D) Fluoride (C)L (D) Racemic 176 MCQs IN BIOCHEMISTRY

ANSWERS 1. A 2. B 3. A 4. D 5. C 6. D 7. C 8. A 9. B 10. D 11. C 12. D 13. A 14. B 15. D 16. A 17. B 18. C 19. B 20. D 21. A 22. A 23. B 24. B 25. D 26. B 27. A 28. A 29. A 30. B 31. C 32. A 33. B 34. C 35. A 36. B 37. A 38. B 39. D 40. C 41. D 42. A 43. A 44. B 45. C 46. A 47. D 48. B 49. C 50. B 51. B 52. A 53. A 54. C 55. C 56. D 57. C 58. C 59. A 60. B 61. A 62. C 63. A 64. D 65. A 66. D 67. A 68. C 69. B 70. B 71. A 72. B 73. A 74. B 75. A 76. B 77. C 78. C 79. A 80. A 81. C 82. C 83. B 84. D 85. B 86. B 87. D 88. D 89. D 90. A 91. A 92. A 93. A 94. B 95. A 96. B 97. A 98. A 99. A 100. A 101. A 102. B 103. A 104. C 105. A 106. D 107. B 108. A 109. D 110. C 111. B 112. B 113. D 114. A 115. B 116. A 117. B 118. C 119. B 120. C 121. A 122. C 123. C 124. D 125. A 126. A 127. B 128. B 129. B 130. B 131. C 132. A 133. D 134. A 135. B 136. B 137. A 138. B 139. B 140. C 141. D 142. B 143. A 144. B 145. B 146. A 147. A 148. C 149. A 150. A 151. B 152. B 153. D 154. A 155. A 156. D 157. A 158. A 159. A 160. A 161. A 162. A 163. B 164. A 165. A 166. B 167. B 168. C 169. A 170. D 171. D 172. A 173. C 174. B 175. B 176. A 177. C 178.A 179. D 180. B 181. D 182. B 183. D 184. C 185. C 186. A 187. D 188. C 189. A 190. A 191. C 192. C 193. A 194. C 195. A 196. A 197. B 198. B 199. B 200. A 201. D 202. C 203. D 204. D 205. B 206. A 207. D 208. A 209. A 210. D 211. A 212. A 213. D 214. D 215. A 216. A 217. A 218. A 219. D 220. D 221. C 222. C 223. B 224. D 225. A 226. A 227. B 228. B 229. D 230. A 231. B 232. D 233. A 234. A 235. D 236. B 237. A 238. C 239. B 240. C 241. B 242. A 243. B 244. A 245. A 246. A 247. A 248. A 249. A 250. C 251. B 252. C ENZYMES 177

253. B 254. D 255. C 256. D 257. A 258. B 259. D 260. C 261. B 262. C 263. A 264. D 265. A 266. B 267. C 268. A 269. B 270. C 271. C 272. A 273. D 274. A 275. B 276. C 277. B 278. C 279. B 280. D 281. C 282. B 283. B 284. D 285. C 286. D 287. C 288. A 289. C 290. D 291. C 292. B 293. C 294. D 295. D 296. B 297. D 298. C 299. B 300. B 301. B 302. D 303. D 304. A 305. B 306. D 307. C 308. B 309. C 310. D 311. A 312. C 313. D 314. B 315. B 316. C 317. C 318. B 319. B 320. A 321. D 322. A 323. A 324. B 325. C 326. C 327. A 328. D 329. B 330. A 331. C 332. C 333. C 334. C 335. D 336. A 337. A 338. D 339. C 340. D 341. C 342. C 343. C 344. A 345. D 346. C 347. C 348. C 349. C 350. C 351. C 352. C 353. C 354. B 355. C 356. A 357. C 358. A 359. D 360. D 361. D 362. B 363. A 364. D 365. C 366. A 367. D 368. A 369. D 370. D 371. C 372. B 373. C 374. A 375. C 376. A 377. B 378. B 379. C 380. B 381. C 382. B 383. B 384. D 385. B 386. C 387. D 388. C 389. D 390. C 391. D 392. C 393. C 394. A 395. D 396. D 397. C 398. C 399. B 400. C 401. D 402. B 403. C 404. B 405. D 406. D 407. A 408. C 409. C 410. D 411. B 412. B 413. B 414. D 415. A 416. C 417. D 418. D 419. C 420. C 421. B 422. D 423. A 424. B 425. D 426. B 427. B 428. D 429. D 430. C 431. D 432. B 433. C 434. A 435. D 436. B 437. A 438. B 439. D 440. B 441. A 442.A 443. B 444. C 445. A 446. A 447. B 448. B 449. B 450. D 451. B 452. C 453. C 454. A 455. D 456. A 457. D 458. B 459. C 460. D 461. B 462. C 463. B 464. D 465. B 466. D 467. D 468. D 469. C 470. B 471. B 472. D 473. D 474. C 475. D 476. D 477. B 478. B 479. D 480. A 481. D 482. B 483. B 484. C 485. C 486. C 487. A 488. A 489. B 490. A 491. A 492. D 493. C 494. B 495. C 496. A 497. A 498. D 499. D 500. D 501. D 502. C 503. C 504. A 505. C 506. A 507. B 508. B 509. B 510. A 178 MCQs IN BIOCHEMISTRY

511. B 512. C 513. A 514. D 515. A 516. A 517. C 518. C 519. B 520. D 521. C 522. C 523. A 524. C 525. B 526. B 527. A 528. A 529. D 530. A 531. D 532. D 533. B 534. A 535. D 536. C 537. A 538. D 539. B 540. A 541. A 542. B 543. C 544. A 545. D 546. D 547. C 548. A 549. B 550. D 551. C 552. A 553. C 554. A 555. B 556. B 557. C 558. B 559. C 560. A 561. D 562. A 563. B 564. B 565. B 566. D 567. A 568. A 569. C 570. D 571. D 572. A 573. C 574. B 575. A 576. C 577. D 578. C 579. B 580. B 581. B 582. B 583. B 584. B 585. C 586. B ENZYMES 179

EXPLANATIONS FOR THE ANSWERS 4. D The functional unit of an enzyme is referred to theory): The substrate fits to active site of an as a holoenzyme. It is often made up of an enzyme just as a key fits into a proper lock. Thus, apoenzyme (the protein part) and a coenzyme the active site of the enzyme is rigid and (the non-protein part). preshaped where only a specific substrate can 47. D Concentration of enzyme, concentration of bind. substrate, temperature, pH, presence of products, (b) Induced fit theory (Koshland model): As per activators and inhibitors are some of the important this, the substrate induces a conformational factors that influence enzyme activity. change in the enzyme resulting in the formation 89. D It is a straight line graphic representation of substrate binding (active) site. depicting the relation between substrate 305. C Some enzymes are synthesized in an inactive concentration and enzyme velocity. This plot is form which are referred to as proenzymes (or commonly employed for the calculation of Km zymogens). They undergo irreversible values for enzymes. modification to produce active enzymes. e.g., 133. D Active site is the small region of an enzyme where proenzymes – chymotrypsinogen and substrate binds. It is flexible in nature and it exists pepsinogen are respectively converted to due to the tertiary structure of proteins. Acidic, chymotrypsin and pepsin. basic and hydroxyl amino aicds are frequently 345. D The RNAs that can function as enzymes are found at the active site. referred to as ribozymes. They are thus non- 179. D There are three broad categories of enzyme protein enzymes. It is believed that RNAs were inhibition: functioning as catalysts before the occurance of (a) Reversible inhibition: The inhibitor binds non- proteins during evolution. covalently with the enzyme and the inhibition is 391. D Streptokinase is used for clearing blood clots. reversible. Competitive, non-competitive and Asparaginase is employed in the treatment uncompetitive come under this category. of leukemias. (b) Irreversible inhibition: The inhibitor 438. B Certain enzymes can be made to bind to covalently binds with the enzyme which is insoluble inorganic matrix (e.g., cyanogens irreversible. bromide activated sepharose) to preserve their (c) Allosteric inhibition: Certain enzymes catalytic activity for long periods. Such enzymes possessing allosteric sites are regulated by are referred to as immobilized enzymes. allosteric effectors. 479. D These enzymes are either totally absent or present 219. D Enzymes are highly specific in their action at a low concentration in plasma compared to compared with chemical catalysts. Three types their levels found in tissues. Estimation of plasma of enzyme specificities are well-recognized. non-functional enzymes is important for the (a) Stereospecificity: The enzymes act only on diagnosis and prognosis of several diseases. one isomer and therefore exhibit stereoisomerism. 514. D Lactate dehydrogenase (LDH) gas five distinct

e.g., L-amino acid oxidase on L-amino acids; isoenzymes (LDH1 … LDH 5). Each one is an hexokinase on D-hexose (Note: isomerases do oligomeric protein composed of 4 subunits (N not exhibit stereospecificity). and/ or H). Isoenzymes of LDH are important for the diagnosis of heart and liver related disorders (b) Reaction specificity: The same substrate can i.e., serum LDH is elevated in myocardial undergo different types of reactions, each catal- 1 infarction while LDH is increased in liver ysed by a separate enzyme e.g., amino acids 5 diseases. undergoing transamination, decarboxylation etc. 559. C Creatine kinase (CK) or creatine phosphokinase (c) Substrate specifity: This may be absolute, relative or broad e.g., urease, ligase, (CPK) exists as 3 isoenzymes. Each isoenzyme is hexokinase. a dimmer composed of two subunits (M or B or both). Elevation of CPK2 (MB) in serum is an 260. D early reliable diagnostic indication of myocardial (a) Lock and Key model (Fischer’s Template infarction. This page intentionally left blank CHAPTER 7

MMMINERALINERALINERAL MMMETETETABOLISMABOLISMABOLISM

1. When ATP forms AMP 7. If ∆∆∆G°= –2.3RT log Keq, the free energy (A) Inorganic pyrophosphate is produced for the reaction will be (B) Inorganic phosphorous is produced ABC+ (C) Phsophagen is produced 10moles 10moles 10moles (D) No energy is produced (A) –4.6 RT (B) –2.3 RT 2. Standard free energy (∆∆∆G°) of hydrolysis (C) +2.3 RT (D) +4.6 RT

of ATP to ADP + Pi is + 8. Redox potential (EO volts) of NAD /NADH (A) –49.3 KJ/mol (B) –4.93 KJ/mol is (C) –30.5 KJ/mol (D) –20.9 KJ/mol (A) –0.67 (B) –0.32 3. Standard free energy (∆∆∆G°) of hydrolysis (C) –0.12 (D) +0.03 of ADP to AMP + Pi is 9. Redox potential (EO volts) of ubiquinone, (A) –43.3 KJ/mol (B) –30.5 KJ/mol ox/red system is (C) –27.6 KJ/mol (D) –15.9 KJ/mol (A) +0.03 (B) +0.08 4. Standard free energy (∆∆∆G°) of hydrolysis (C) +0.10 (D) +0.29 of phosphoenolpyruvate is 10. Redox potential (E volts) of cytochrome (A) –61.9 KJ/mol (B) –43.1 KJ/mol O C, Fe3+/Fe2+ is (C) –14.2 KJ/mol (D) –9.2 KJ/mol (A) –0.29 (B) –0.27 5. Standard free energy (∆∆∆G°) of hydrolysis (C) –0.08 (D) +0.22 of creatine phosphate is (A) -–51.4 KJ/mol (B) –43.1 KJ/mol 11. The prosthetic group of aerobic dehydro- genases is (C) –30.5 KJ/mol (D) –15.9 KJ/mol (A) NAD (B) NADP 6. The oxidation-reduction system having (C) FAD (D) Pantothenic acid the highest redox potential is (A) Ubiquinone ox/red 12. Alcohol dehydrogenase from liver con- (B) Fe3+ cytochrome a/Fe2+ tains (C) Fe3+ cytochrome b/Fe2+ (A) Sodium (B) Copper (D) NAD+/NADH (C) Zinc (D) Magnesium 182 MCQs IN BIOCHEMISTRY

13. A molybdenum containing oxidase is 22. The sequence of the redox carrier in (A) Cytochrome oxidase respiratory chain is (B) Xanthine oxidase (A) NAD—FMN—Q—cyt b—cyt c1—cyt c—cyt (C) Glucose oxidase aa3 → O2 (D) L-Amino acid oxidase (B) FMN—Q—NAD—cyt b—cyt aa3—cyt c1— 14. A copper containing oxidase is cyt c → O2 (A) Cytochrome oxidase (C) NAD—FMN—Q—cyt c1—cyt c—cyt b—cyt (B) Flavin mononucleotide aa3 → O2 (C) Flavin adenine dinucleotide (D) NAD—FMN—Q—cyt b—cyt aa —cyt c—cyt (D) Xanthine oxidase 3 c1 → O2 15. The mitochondrial contains 23. The correct sequence of cytochrome (A) Mg++ (B) Mn++ carriers in respiratory chain is ++ ++ (C) Co (D) Zn (A) Cyt b—cyt c—cyt c1—cyt aa3 (B) Cyt aa — cyt b—cyt c—cyt c 16. Cytosolic superoxide dismutase contains 3 1 (C) Cyt b—cyt c —cyt c—cyt aa (A) Cu2+ and Zn2+ (B) Mn2+ 1 3 (D) Cyt b—cyt aa —cyt c — cyt c (C) Mn2+ and Zn2+ (D) Cu2+ and Fe2+ 3 1 24. Reducing equivalents from pyruvate enter 17. Cytochrome oxidase contains the mitochondrial respiratory chain at (A) Cu2+ and Zn2+ (B) Cu2+ and Fe2+ (A) FMN (B) NAD (C) Cu2+ and Mn2+ (D) Cu2+ (C) Coenzyme Q (D) Cyt b 18. Characteristic absorption bands exhibited by ferrocytochrome: 25. Reducing equivalents from succinate enter the mitochondrial respiratory chain at (A) α band (B) β band (C) α and β bands (D) α, β and γ bands (A) NAD (B) Coenzyme Q (C) FAD (D) Cyt c 19. Monooxygenases are found in (A) Cytosol (B) Nucleus 26. The respiratory chain complexes acting as proton pump are (C) Mitochondira (D) Microsomes (A) I, II and III (B) I, II and IV 20. A component of the respiratory chain in (C) I, III and IV (D) I and II mitochondria is (A) Coenzyme Q 27. If the reducing equivalents enter from FAD (B) Coenzyme A in the respiratory chain, the phos- (C) Acetyl coenzyme phate.oxygen ration (P:O) is (D) Coenzyme containing thiamin (A) 2 (B) 1 (C) 3 (D) 4 21. The redox carriers are grouped into respiratory chain complex 28. If the reducing equivalents enter from (A) In the inner mitochondrial membrane NAD in the respiratory chain, the (B) In mitochondiral matrix phsphate/oxygen (P:O) is (C) On the outer mitochondrial membrane (A) 1 (B) 2 (D) On the inner surface of outer mitochondrial (C) 3 (D) 4 membrane MINERAL METABOLISM 183

29. One of the site of phsosphorylation in 37. The chemical inhibiting oxidative phos- mitochondrial respiratory chain is phorylation, Adependent on the transport (A) Between FMN and coenzyme Q of adenine nucleotides across the inner mitochondrial membrane is (B) Between coenzyme Q and cyt b (A) Oligomycin (B) Atractyloside (C) Between cytochrome b and cytochrome c1 (C) Dinitrophenol (D) Pentachlorophenol (D) Between cytochrome c1 and cytochrome c 30. Rotenone inhibits the respiratory chain at 38. Porphyrins are synthesized in (A) FMN → coenzyme Q (A) Cytosol (B) NAD → FMN (B) Mitochondria (C) Coenzyme Q → cyt b (C) Cytosol and mitochondria

(D) Cyt b → Cyt c1 (D) Rough endoplasmic reticulum 31. Activity of cytochrome oxidase is inhibited 39. Heme is synthesized from by (A) Succinyl-CoA and glycine (A) Sulphite (B) Sulphate (B) Active acetate and glycine (C) Arsenite (D) Cyanide (C) Active succinate and alanine 32. Transfer of reducing equivalents from (D) Active acetate and alanine succinate dehydrogenase to coenzyme Q 40. In the biosynthesis of the iron protopor- is specifically inhibited by phyrin, the product of the condensation (A) Carboxin (B) Oligomycin between succinyl-CoA and glycine is (C) Piericidin A (D) Rotenone (A) α-Amino β-ketoadipic acid 33. Chemiosmotic theory for oxidative (B) δ-Aminolevulinate phosphorylation has been proposed by (C) Hydroxymethylbilane (A) Chance and Williams (D) Uroporphyrinogen I

(B) Pauling and Corey 41. Porphyrin synthesis is inhibited in (C) S. Waugh (A) Mercury poisoning (D) P. Mitchell (B) Lead poisoning 34. The number of ATP produced in the (C) Manganese poisoning oxidation of 1 molecule of NADPH in (D) Barium poisoning oxidative phosphorylation is (A) Zero (B) 2 42. During synthesis of porphyrins, synthesis of δδδ-amino levulinic acid occurs in (C) 3 (D) 4 (A) Mitochondria 35. The coupling of oxidation and phosphory- (B) Cytosol lation in intact mitochondria: (C) Both in mitochondria and cytosol (A) Puromycin (B) Oligomycin (D) Ribosomes (C) Streptomycin (D) Gentamycin 43. In the biosynthesis of heme, condensation 36. An uncoupler of oxidative phosphoryla- between succinyl CoA and glycine requires tion is (A) NAD+ (B) FAD (A) Carboxin (B) Atractyloside (C) NADH + H+ (D) B -phosphate (C) Amobarbital (D) Dinitrocresol 6 184 MCQs IN BIOCHEMISTRY

44. In mammalian liver the rate controlling 51. The synthesis of heme from protophyrin enzyme in porphyrin biosynthesis is III is catalysed by the enzyme: (A) ALA synthase (A) ALA synthase (B) Ferroreductase (B) ALA hydratase (C) Ferrooxidase (D) (C) Uroporphyrinogen I synthase 52. Many xenobiotics (D) Uroporphyrinogen III cosynthase (A) Increase hepatic ALA synthase 45. The condensation of 2 molecules of (B) Decrease hepatic ALA sythase δδδ-aminolevulinate dehydratase contains (C) Increase hepatic ALA dehydrase (D) Decrease hepatic ALA dehydrase (A) ALA synthase (B) ALA hydratase 53. Acute intermittent porphyria (paraoxymal porphyria) is caused due to deficiency of (C) Uroporphyrinogen synthase I (D) Uroporphyrinogen synthase III (A) Uroporphyrinogen I synthase (B) ALA synthase 46. The enzyme δδδ-aminolevulinate dehy- (C) Coproporphyrinogen oxidase dratase contains (D) Uroporphyrinogen decarboxylase (A) Zinc (B) Manganese 54. The major symptom of acute intermittent (C) Magnesium (D) Calcium porphyria includes 47. A cofactor required for the activity of the (A) Abdominal pain enzyme ALA dehydratase is (B) Photosensitivity (A) Cu (B) Mn (C) No neuropsychiatric signs (C) Mg (D) Fe (D) Dermatitis 55. The characteristic urinary finding in acute 48. The number of molecules of porphobili- intermittent porphyria is nogen required for the formation of a tet- rapyrrole i.e., a porphyrin is (A) Increased quantity of uroporphyrin (B) Increased quantity of coproporphyrin I (A) 1 (B) 2 (C) Increased quantity of coproporphyrin III (C) 3 (D) 4 (D) Massive quantities of porphobilinogen 49. Conversion of the linear tetrapyrrole 56. The enzyme involved in congenial eryth- hydroxymethylbilane to uroporphyrino- ropoietic porphyria is gen III (A) Uroporphyrinogen I synthase (A) Occurs spontaneously (B) Uroporphyrinogen III cosynthase (B) Catalysed by uroporphyrinogen I synthase (C) Protoporphyrinogen oxidase (C) Catalysed by uroporphyrinogen III cosynthase (D) Ferrochelatase (D) Catalysed by combined action of uroporphy- 57. Main symptoms of congenital erythropoi- rinogen I synthase and uroporphyrinogen III etic porphyria is cosynthase (A) Yellowish teeth (B) Photosensitivity 50. Conversion of uroporphyrinogen III to (C) Abdominal pain (D) Brownish urine coprophyrinogen III is catalysed by the 58. The probable cause of porphyria cutanea enzyme.: tarda is deficiency of (A) Uroporphyrinogen decarboxylase (A) Uroporphyrinogen oxidase (B) Coproporphyrinogen oxidase (B) Coproporphyrinogen oxidase (C) Protoporphyrinogen oxidase (C) Protoporphyrinogen oxidase (D) Ferrochelatase (D) Uroporphyrinogen I synthase MINERAL METABOLISM 185

59. The characteristic urinary finding in por- 66. All immunoglobulins contain phyria cutanea tarda is (A) 4 L chains (A) Increased quantity of porphobilinogen (B) 4 H chains (B) Increased quantity of red cell protoporphyrin (C) 3 L chains (C) Increased quantity of uroporphyrin (D) 2 L chains and 2 H chains (D) Increased quantity of δ-ALA 67. An immunoglobulin molecule always contains 60. Hereditary coproporphyria is caused due to deficiency of (A) 1 κ and 3 λ type of chains (B) 2 κ and 2 λ type of chains (A) Protoporphyrinogen oxidase (C) 3 κ and 1λ type of chains (B) ALA synthase (D) 2 κ and 2 λ chains (C) ALA dehydratase 68 . The number of types of H chains identified (D) Coproporphyrinogen oxidase in human is 61. The enzyme involved in variegate por- (A) 2 (B) 3 phyria is (C) 4 (D) 5 (A) Protoporphyrinogen oxidase 69. The number of hypervariable region in L (B) Coproporphyrinogen oxidase chain is (C) Uroporphyrinogen decarboxylase (A) 1 (B) 2 (D) ALA decarboxylase (C) 3 (D) 4 62. Protoporphyria (erythrohepatic) is char- 70. The number of hypervariable region in H acterized by the deficiency of chain is (A) ALA synthase (A) 1 (B) 2 (B) ALA hydratase (C) 3 (D) 4 (C) Protophyrinogen oxidae 71. Type γ H chain is present in (D) Ferrochelatase (A) Ig G (B) Ig A 63. The amount of coproporphyrins excreted (C) Ig M (D) Ig D per day in feces is about 72. Type ααα H chain is present in (A) 10–50 µgs (B) 100–150 µgs (A) Ig E (B) Ig A (C) 200–250 µgs (D) 300–1000 µgs (C) Ig M (D) Ig D

64. The immunoglobulins are differentiated 73. Type µµµ H chain is present in and also named on the basis of (A) Ig G (B) Ig A (A) Electrophoretic mobility (C) Ig M (D) Ig D (B) Heat stability 74. Type δ H chain is present in (C) Molecular weight (A) Ig G (B) Ig A (D) Sedimentaiton coefficient like 7 S, 19 S etc. (C) Ig M (D) Ig D 65. The immunoglobulins are classified on the 75. Type εεε H chain is present in basis of (A) Ig A (B) Ig M (A) Light chains (C) Ig D (D) Ig E (B) Heavy chains 76. A ‘J’ chain is present in (C) Carbohydrate content (A) Ig D (B) Ig M (D) Electrophoretic mobility (C) Ig G (D) Ig E 186 MCQs IN BIOCHEMISTRY

77. A secretory protein T chain (T protein) is 85. The immunoglobulin which can cross the present in placenta is (A) Ig A (B) Ig M (A) Ig A (B) Ig M (C) Ig D (D) Ig E (C) Ig G (D) Ig D 78. A pentamer immunoglobulin is 86. The immunoglobulin possessing lowest (A) Ig G (B) Ig A concentration of carbohydrate is (C) Ig M (D) Ig E (A) Ig A (B) Ig E 79. The portion of the immunoglobulin (C) Ig M (D) Ig G molecule that binds the specific antigen 87. The normal serum level of Ig G is is formed by (A) 1200 mg% (B) 500 mg% (A) Variable regions of H and L chains (C) 300 mg% (D) 200 mg% (B) Constant region of H chain (C) Constant region of L chain 88. The half life of Ig G is (D) Hinge region (A) 2–8 days (B) 1–4 days 80. The class specific function of the different (C) 19–24 days (D) 6 days immunoglobulin molecules is constituted 89. Most heat labile immunoglobulin is by (A) Ig G (B) Ig A (A) Variable region of L chain (C) Ig M (D) Ig D (B) Constant region of H chain (C) Variable region of H chain 90. The immunoglobulin possessing highest concentration of carbohydrate is (D) Constant region particularly CH2 and CH3 of H chain (A) Ig G (B) Ig M 81. Hinge region, the region of Ig molecule (C) Ig A (D) Ig D which is flexible and more exposed to 91. The normal serum level of Ig D is enzymes is the (A) 1 mg% (B) 2 mg% (A) Region between first and second constant (C) 3 mg% (D) 5 mg% regions of H chain (domains CH1 and CH2) 92. The half life of Ig D is (B) Region between second and third constant (A) 1 day (B) 2–8 days regions of H chain (C 2 and C 3) H H (C) 10–15 days (D) 20–24 days (C) Variable regions of H chain (D) Variable regions of L chain 93. The carbohydrate content of Ig M is about (A) 2.8% (B) 6.4% 82. The smallest immunoglobulin is (C) 8.0% (D) 10.2% (A) Ig G (B) Ig E (C) Ig D (D) Ig A 94. The immunoglobulin having highest sedimentation coefficient is 83. The number of sub classes of Ig G is (A) Ig G (B) Ig A (A) 2 (B) 3 (C) Ig M (D) Ig D (C) 4 (D) 8 95. The immunoglobulin having highest 84. Most abundant Ig G subclass in the serum molecular weight is is (A) Ig G (B) Ig M (A) Ig G (B) Ig G 1 2 (C) Ig E (D) Ig A (C) Ig G3 (D) Ig G4 MINERAL METABOLISM 187

96. The half life of Ig M is 107. The normal serum level of phosphorus in (A) 2 days (B) 4 days human adult is (C) 5 days (D) 8 days (A) 1–2 mg (B) 2–3 mg (C) 3–4.5 mg (D) 5–7 mg 97. The normal serum level of Ig M is (A) 50 mg% (B) 120 mg% 108. An increase in carbohydrate metabolism (C) 200 mg% (D) 300 mg% is accompanied by temporary decrease in serum: 98. The immunoglobulin associated with reginic antibody is (A) Calcium (B) Phosphate (C) Iron (D) Sodium (A) Ig E (B) Ig D (C) Ig M (D) Ig A 109. In rickets of the common low-phosphate variety, serum phosphate values may go 99. The immunoglobulin having least concen- as low as tration in serum is (A) 1–2 mg/100 ml (B) 2–3 mg/100 ml (A) Ig A (B) Ig M (C) Ig D (D) Ig E (C) 3–4 mg/100 ml (D) 4–5 mg/100 ml 100. The half life of Ig E protein is 110. The normal serum level of phosphorous in children varies from (A) 1–6 days (B) 2–8 days (A) 1–2 mg/100 ml (B) 2–3 mg/100 ml (C) 10 days (D) 20 days (C) 3–4 mg/100 ml (D) 4–7 mg/100 ml 101. The immunoglobulin which provides highest antiviral activity is 111. An inherited or acquired renal tubular defect in the reabsorption of phosphate (A) Ig D (B) Ig E (Vit D resistant ricket) is characterized (C) Ig A (D) Ig G with 102. The half life of Ig A is (A) Normal serum Phosphate (A) 6 days (B) 2–4 days (B) High serum phosphate (C) 5–10 days (D) 12–20 days (C) A low blood phosphorous with elevated 103. The normal serum level of Ig A is alkaline Phosphate (D) A high blood phosphorous with decreased (A) 100 mg% (B) 200 mg% alkaline phosphatase (C) 300 mg% (D) 400 mg% 112. The total magnesium content in gms of 104. Calcium is excreted by human body is about (A) Kidney (A) 5 (B) 10 (B) Kidney and intestine (C) 15 (D) 21 (C) Kidney and liver (D) Kidney and pancreas 113. Iron is a component of (A) Hemoglobin (B) Ceruloplasmin 105. A decrease in the ionized fraction of serum calcium causes (C) Transferase (D) Transaminase (A) Tetany (B) Rickets 114. Daily requirement of iron for normal (C) Osteomalacia (D) Osteoporosis adult male is about 106. A rise in blood calcium may indicate (A) 5 mg (B) 10 mg (C) 15 mg (D) 20 mg (A) Paget’s disease (B) Rickets (C) Osteomalacia (D) Hypervitaminosis D 188 MCQs IN BIOCHEMISTRY

115. The normal content of protein bound iron 123. The best source of iron is (PBI) in the plasma of males is (A) Organ meats (B) Milk (A) 120–140 µg/100 ml (C) Tomato (D) Potato (B) 200–300 µg/100 ml 124. An increased serum iron and decreased (C) 120–140 µg/100 ml iron binding capacity is found in (D) 200–300 µg/100 ml (A) Fe deficiency anemia 116. In iron deficiency anemia (B) Sideroblastic anemia (A) The plasma bound iron is low (C) Folate deficiency anemia (B) The plasma bound iron is high (D) Sickle cell anemia (C) Total iron binding capacity is low 125. The absorption of iron is increased 2–10 (D) Both the plasma bound iron and total iron times of normal in binding capacity are low (A) Iron deficiency anemia 117. The total iron content of the human body (B) Pregnancy is (C) Spherocytosis (A) 400–500 mg (B) 1–2 g (D) Sickle cell anemia (C) 2–3 g (D) 4–5 g 126. Iron is mainly absorbed from 118. In hepatic diseases (A) Stomach and duodenum (B) Ileum (A) Both the bound iron and total iron binding capacity of the plasma may be low (C) Caecum (B) Both the bound iron and total iron binding (D) Colon capacity of the plasma may be high 127. The iron containing nonporphyrin is (C) Only bound iron may be high (A) Hemosiderin (B) Catalase (D) Only the total iron binding capacity may be (C) Cytochrome C (D) Peroxidase high 128. Molecular iron is 119. The recommended daily requirement of iron for women of 18–55 yrs age is (A) Stored primarily in the spleen (B) Exreted in the urine as Fe2+ (A) 5 mg (B) 8 mg (C) Stored in the body in combination with ferritin (C) 10 mg (D) 15 mg (D) Absorbed in the ferric form 120. The percent of total iron in body in 129. In hemochromatosis, the liver is infiltrated hemoglobin is with (A) 10–20 (B) 20–30 (A) Iron (B) Copper (C) 30–40 (D) 60–70 (C) Molybdenum (D) Fats 121. A hypochromic microcytic anemia with 130. An acquired siderosis-Bantu siderosis is increased iron stores in the bone marrow due to may be (A) Foods cooked in iron pots (A) Iron responsive (B) Diet high in phosphorous (B) Pyridoxine responsive (C) Diet high in calcium (C) Vitamin B12 responsive (D) High fat diet (D) Folate responsive 131. The amount of copper in the human body 122. A good source of iron is is (A) Spinach (B) Milk (A) 50–80 mg (B) 100–150 mg (C) Tomato (D) Potato (C) 400–500 mg (D) 500–1000 mg MINERAL METABOLISM 189

132. The amount of copper in muscles is about 142. Menke’s disease is due to an abnormality (A) 10 mg (B) 30 mg in the metabolism of (C) 64 mg (D) 100 mg (A) Iron (B) Manganese (C) Magnesium (D) Copper 133. The amount of copper in bones is about (A) 5 mg (B) 10 mg 143. Menke’s disease (Kinky or steel hair dis- ease) is a X-linked disease characterized (C) 15 mg (D) 23 mg by 134. The normal serum of concentration of (A) High levels of plasma copper copper in mg/100 ml varies between (B) High levels of ceruloplasmin (A) 0–5 (B) 50–100 (C) Low levels of plasma copper and of ceulo- (C) 100–200 (D) 200–300 (D) High level of hepatic copper 135. The normal serum concentration of ceru- loplasmin in mg/100 ml varies between 144. The trace element catalyzing hemoglobin (A) 5–10 (B) 10–20 synthesis is (C) 25–43 (D) 50–100 (A) Manganese (B) Magnesium 136. Recommended daily dietary requirement (C) Copper (D) Selenium of copper for adults is 145. The total body content of manganese is (A) 0.5–1 mg (B) 1.5–3.0 mg about (C) 3.5–4.5 mg (D) 4.5–5.5 mg (A) 2 mg (B) 4 mg 137. The richest source of copper is (C) 8 mg (D) 10 mg (A) Liver 146. In blood the values of manganese in µµµg / (B) Milk 100 ml varies between (C) Legumes (A) 0–4 (B) 2–4 (D) Green leafy vegetables (C) 3–5 (D) 4–20 138. The cytosolic superoxide dismutase 147. The adequate daily dietary requirement enzyme contains of manganese is 2+ 2+ 2+ (A) Cu (B) Cu and Zn (A) 1–2 mg (B) 2–5 mg 2+ 2+ (C) Zn (D) Mn (C) 5–10 mg (D) 10–20 mg 139. The deficiency of copper decreases the 148. Mitochondrial superoxide dismutase activity of the enzyme: contains (A) Lysine oxidase (B) Lysine hydroxylase (A) Zinc (B) Copper (C) Tyrosine oxidase (D) Proline hydroxylase (C) Magnesium (D) Manganese 140. Wilson’s disease is a condition of toxicosis 149. Mitochondrial pyruvate carboxylase of contains (A) Iron (B) Copper (A) Zinc (B) Zinc (C) Chromium (D) Molybdenum (C) Manganese (D) Magnesium 141. In Wilson’s disease 150. The adequate daily dietary requirement (A) Copper fails to be excreted in the bile of molybdenum for normal human adult (B) Copper level in plasma is decreased is (C) Ceruloplasmin level is increased (A) 10–20 µg (B) 25–50 µg (D) Intestinal absorption of copper is decreased (C) 50–70 µg (D) 75–200 µg 190 MCQs IN BIOCHEMISTRY

151. In human beings molybdenum is mainly 161. Total body content of selenium is about absorbed from (A) 1–2 mg (B) 2–4 mg (A) Liver (B) Kidney (C) 4–10 mg (D) 50–100 mg (C) Intestine (D) Pancreas 162. Normal serum level of selenium is 152. In human beings molybdenum is mainly (A) 5 µg /100 ml (B) 8 µg /100 ml excreted in (C) 10 µg /100 ml (D) 13 µg /100 ml (A) Feces (B) Sweat (C) Urine (D) Tears 163. Selenium is a constituent of the enzyme: (A) 153. Molybdenum is a constituent of (B) Homogentisate oxidase (A) Hydroxylases (B) Oxidases (C) Tyrosine hydroxylase (C) Transaminases (D) Transferases (D) Phenylalanin hydroxylase 154. Safe and adequate daily dietary intake 164. A nonspecific intracellular antioxidant is of chromium in adults in mg is (A) 0.01–0.02 (B) 0.02–0.03 (A) Chromium (B) Magnesium (C) 0.03–0.04 (D) 0.05–0.2 (C) Selenium (D) Nickel

155. Richest source of chromium is 165. Cobalt forms an integral part of the vitamin: (A) Brewer’s yease (A) B (B) B (B) Milk and milk products 1 6 (C) B (D) Folate (C) Yellow vegetables 12 (D) Green vegetables 166. Cobalt may act as cofactor for the enzyme: 156. Metallic constituent of “Glucose tolerance (A) Glycl-glycine factor” is (B) Elastase (A) Sulphur (B) Cobalt (C) Polynucleotidases (C) Chromium (D) Selenium (D) Phosphatase 157. Intestinal absorption of chromium is 167. Excess intake of cobalt for longer periods shared with leads to (A) Mn (B) Mg (A) Polycythemia (C) Ca (D) Zn (B) Megaloblastic anemia (C) Pernicious anemia 158. Serum level of chromium in healthy adult is about (D) Microcytic anemia (A) 2-5 µg/100 ml (B) 6-20 µg/100 ml 168. The total sulphur content of the body is (C) 30-60 µg/100 ml (D) 50-100 µg/100 ml (A) 25–50 gm (B) 50–75 gm 159. Chromium is potentiator of (C) 100–125 gm (D) 150–200 gm (A) Insulin (B) Glucagon 169. Sulphur is made available to the body by (C) Thyroxine (D) Parathromone the amino acids: (A) Cystine and methionine 160. Recommended daily dietary allowance of selenium for adult human in µµµg is (B) Taurine and alanine (C) Proline and hydroxyproline (A) 20 (B) 40 (C) 50 (D) 70 (D) Arginine and lysine MINERAL METABOLISM 191

170. Sulphur containing coenzyme is 179. Dental caries occur due to (A) NAD (A) Drinking water containing less than 0.2 ppm (B) FAD of fluorine (C) Pyridoxal phosphate (B) Drinking water containing greater than 1.2 (D) Biotin ppm of fluorine 171. Iodine is stored in (C) Drinking water containing high calcium (A) Thyroid gland as thyroglobulin (D) Drinking water containing heavy metals (B) Liver 180. Total zinc content of human body is about (C) Intestine (A) 800 mg (B) 1200 mg (D) Skin (C) 2000 mg (D) 3200 mg 172. Iodine is the constituent of 181. Metal required for polymerization of (A) T and T (B) PTH 3 4 insulin is (C) Insulin (D) Adrenaline (A) Copper (B) Chromium 173. Goitrogenic substance present in cabbage (C) Cobalt (D) Zinc is (A) 5-vinyl-2 thio oxalzolidone 182. Metalloenzyme-retinene for polymeriza- tion of insulin is (B) Pyridine-3-carboxylic acid (C) 3-Hydroxy-4, 5-dihydroxymethyl1–2-methyl (A) Copper (B) Zinc pyridine (C) Cobalt (D) Manganese (D) δ-ALA dehydratase 183. An important zinc containing enzyme is 174. For an adult male daily requirement of (A) iodine is (B) Isocitrate dehydrogenase (A) 25–50 µg (B) 50–100 µg (C) Cholinesterate (C) 100–150 µg (D) 200–250 µg (D) Lipoprotein lipase 175. Recommended daily intake of fluoride for 184. Acrodermatitis enteropathica is due to a normal adult is defective absorption of (A) 1.5–4.0 mg (B) 0–1 mg (A) Manganese (B) Molybdenum (C) 5–10 mg (D) 10–20 mg (C) Iodine (D) Zinc 176. The percentage of fluoride present in normal bone is 185. Hypogonadism develops due to deficiency of (A) 0.01–0.03 (B) 0.04–0.08 (A) Sulphur (B) Cobalt (C) 0.10–0.12 (D) 0.15–0.2 (C) Zinc (D) Manganese 177. The percentage of fluoride present in dental enamel is 186. Psychotic symptoms and parkinsonism like symptoms develop due to inhalation (A) 0.01–0.02 (B) 0.05–0.10 poisoning of (C) 0.15–0.20 (D) 0.20–0.40 (A) Manganese (B) Phosphorous 178. Fluorosis occurs due to (C) Magnesium (D) Zinc (A) Drinking water containing less than 0.2 ppm of fluorine 187. One gram of carbohydrate on complete (B) Drinking water containing high calcium oxidation in the body yields about (C) Drinking water containing greater than 1.2 (A) 1 Kcal (B) 4 Kcal ppm of fluroine (C) 6 Kcal (D) 9 Kcal (D) Drinking water containing heavy metals 192 MCQs IN BIOCHEMISTRY

188. One gram of fat on complete oxidation 199. B.M.R. is subnormal in in the body yields about (A) Addison’s disease (A) 4 Kcal (B) 6 Kcal (B) Adrenal tumour (C) 9 Kcal (D) 12 Kcal (C) Cushing’s syndrome (D) Fever 189. One gram of protein on complete oxida- tion in the body yields about 200. A healthy 70 kg man eats a well balanced (A) 2 Kcal (B) 4 Kcal diet containing adequate calories and 62.5 g of high quality protein per day. (C) 8 Kcal (D) 12 Kcal Measured in grams of nitrogen, his daily 190. R.Q. of mixed diet is about nitrogen balance would be (A) 0.70 (B) 0.80 (A) +10 g (B) +6.25 g (C) 0.85 (D) 1.0 (C) 0 g (D) –6.25 g 191. R.Q. of proteins is about 201. The percentage of nitrogen retained in the body after absorption of diet represents (A) 0.70 (B) 0.75 (A) Digestibility coefficient of proteins (C) 0.80 (D) 0.85 (B) Biological value of proteins 192. R.Q. of carbohydrates is about (C) Protein efficiency ratio (A) 0.75 (B) 0.80 (D) Net protein utilisation (C) 0.85 (D) 1.0 202. In a person increase in weight in gms per 193. R.Q. of fats is about gm of protein consumption represents (A) 0.75 (B) 0.80 (A) Protein efficiency ratio (C) 0.85 (D) 1.0 (B) Digestibility value of proteins (C) Biological value of proteins 194. Proteins have the SDA: (D) Net protein utilisation (A) 5% (B) 10% 203. The percentage of food nitrogen that is (C) 20% (D) 30% retained in the body represents 195. Humans most easily tolerate a lack of the (A) Digestibility coefficient nutrient: (B) Biological value of proteins (A) Protein (B) Lipid (C) Protein efficiency ratio (C) Iodine (D) Carbohydrate (D) Net protein utilisation 196. The basal metabolic rate (B.M.R.) is 204. The chemical score of different proteins is measurement of calculated in terms of (A) Energy expenditure during sleep (A) Egg proteins (B) Milk proteins (B) Energy expenditure after 100 m walk (C) Fish proteins (D) Wheat proteins (C) Energy expenditure after a meal 205. Biological value of egg protein is (D) Energy expenditure under certain basal (A) 94 (B) 60 (Standard) conditions (C) 51 (D) 40 197. B.M.R. is raised in 206. Biological value of protein of cow’s milk is (A) Polycythemia (B) Starvation (A) 95 (B) 60 (C) Lipid nephrosis (D) Hypothyroidism (C) 71 (D) 67 198. B.M.R. is lowered in 207. Biological value of soyabean protein is (A) Hypothyroidism (B) Leukemia (A) 86 (B) 71 (C) Cardiac failure (D) Hyperthyroidism (C) 64 (D) 54 MINERAL METABOLISM 193

208. Plasma bicarbonate is decreased in 216. Respiratory acidosis occurs in (A) Respiratory alkalosis (A) Any disease which impairs respiration like (B) Respiratory acidosis emphysema (C) Metabolic alkalosis (B) Renal disease (D) Metabolic acidosis (C) Poisoning by an acid 209. Plasma bicarbonate is increased in (D) Pyloric stenosis (A) Respiratory alkalosis 217. Metabolic alkalosis occurs (B) Metabolic alkalosis (A) As consequence of high intestinal obstruction (C) Respiratory acidosis (B) In central nervous system disease (D) Metabolic acidosis (C) In diarrhoea 210. Total CO is increased in 2 (D) In colitis (A) Respiratory acidosis (B) Metabolic alkalosis 218. Respiratory alkalosis occurs in (C) Both respiratory acidosis and metabolic (A) Hysterical hyperventilation alkalosis (B) Depression of respiratory centre (D) Respiratory alkalosis (C) Renal diseases 211. Respiratory acidosis is caused by (D) Loss of intestinal fluids (A) Increase in carbonic acid relative to 219. Morphine poisoning causes bicarbonate (B) Decrease in bicarbonate fraction (A) Metabolic acidosis (C) Increase in bicarbonate fraction (B) Respiratory acidosis (E) Decrease in the carbonic acid fraction (C) Metabolic alkalosis (D) Respiratory alkalosis 212. Respiratory alkalosis is caused by (A) An increase in carbonic acid fraction 220. Salicylate poisoning in early stages causes (B) A decrease in bicarbonic fraction (A) Metabolic acidosis (C) A decrease in the carbonic acid fraction (B) Respiratory acidosis (D) An increase in bicarbonate fraction (C) Metabolic alkalosis 213. Meningitis and encephalitis cause (D) Respiratory alkalosis

(A) Metabolic alkalosis 221. The compound having the lowest redox (B) Respiratory alkalosis potential amongst the following is (C) Metabolic acidosis (A) Hydrogen (B) NAD (D) Respiratory acidosis (C) Cytochrome b (D) Cytochrome a 214. Metabolic acidosis is caused in 222. All the oxidases contain a metal which is (A) Uncontrolled diabetes with ketosis (B) Pneumonia (A) Copper (B) FAD (C) Intestinal Obstruction (C) Manganese (D) None of these (D) Hepatic coma 223. Isocitrate dehydrogenases is 215. Metabolic acidosis is caused in (A) Aerobic dehydrogenase (A) Pneumonia (B) Anaerobic dehydrogenase (B) Prolonged starvation (C) Hydroperoxidase (C) Intestinal obstruction (D) Oxygenase (D) Bulbar polio 194 MCQs IN BIOCHEMISTRY

224. Iron-pophyrin is present as prosthetic 234. The porphyrin present in haem is group in (A) Uroporphyrin (B) Protoporphyrin I (A) Cytochromes (B) (C) Coproporphyrin (D) Protoporphyrin II (C) Peroxidase (D) None of these 235. An amino acid required for porphyrin 225. Microsomal hydroxylase system contains synthesis is a (A) Proline (B) Glycine (A) Di-oxygenase (B) Mono-oxygenase (C) Serine (D) Histidine (C) Both (A) and (B) (D) None of thse 236. Which of the following coenzyme is 226. Superoxide radicals can be detoxified by required for porphyrin synthesis? (A) Cytochrome c (B) Cytochrome b (A) Coenzyme A (C) Cytochrome a (D) None of these (B) Pyridoxal phosphate 227. A copper containing cytochrome is (C) Both (A) and (B) (A) Cytochrome a (B) Cytochrome P-450 (D) None of these

(C) Cytochrome a3 (D) None of these 237. The regulatory enzyme for haem synthesis is 228. Rate of tissue respiration is raised when the intracellular concentration of (A) ALA synthetase (A) ADP increases (B) ATP increases (B) haem synthetase (C) ADP decreases (D) None of these (C) Both (A) and (B) (D) None of these 229. Which of the following component of respiratory chain is not attached to the 238. Regulation of haem synthesis occurs by inner mitochondrial membrane? (A) Covalent modification (A) Coenzyme Q (B) Cytochrome c (B) Repression - derepression (C) Both (A) and (B) (D) None of these (C) Induction 230. In some reactions, energy is captured in (D) Allosteric regulation the form of 239. Sigmoidal oxygen dissociation curve is a (A) GTP (B) UTP property of (C) CTP (D) None of these (A) Haemoglobin 231. Substrate-linked phosphorylation occurs (B) Carboxyhaemoglobin in (C) Myoglobin (A) Glycolytic pathway (B) Citric acid cycle (D) Methaemoglobin (C) Both (A) and (B) (D) None of these 240. Cyanmethaemoglobin can be formed 232. Hydrogen peroxide may be detoxified in from the absence of an oxygen acceptor by (A) Oxy Hb (B) Met Hb (A) Peroxidase (B) Catalase (C) Carboxy Hb (D) All of these (C) Both (A) and (B) (D) None of these 241. In thalassemia, an amino acid is substituted 233. Superoxide radicals can be detoxified by in (A) Cytochrome c (A) Alpha chain (B) Superoxide dismutase (B) Beta chain (C) Both (A) and (B) (C) Alpha and beta chains (D) None of these (D) Any chain MINERAL METABOLISM 195

242. Haem synthetase is congenitally deficient 249. Bilirubin UDP-glucuronyl transferase is in absent from liver in (A) Congenital erythropoietic porphyria (A) Crigler-Najjar syndrome, type I (B) Protoporphyria (B) Gilbert’s disease (C) Hereditary coproporphyria (C) Crigler-Najjar syndrome, type II (D) Variegate porphyria (D) Rotor’s syndrome

243. During breakdown of haem, the methenyl 250. Unconjugated bilirubin in serum is bridge between the following two pyrrole soluble in rings is broken: (A) Water (B) Alkalis (A) I and II (B) II and III (C) Acids (D) Methanal (C) III and IV (D) IV and I 251. Excretion of conjugated bilirubin from liver cells into biliary canaliculi is defective in 244. Pre- hepatic jaundice occurs because of (A) Gilbert’s disease (A) Increased haemolysis (B) Crigler-Najjar syndrome (B) Liver damage (C) Lucey-Driscoll syndrome (C) Biliary obstruction (D) Rotor’s syndrome (D) None of these 252. Breakdown of 1gm haemoglobin pro- 245. kernicterus can occur in duces (A) Haemolytic jaundice (A) 20 mg of bilirubin (B) 35 mg of bilirubin (B) Hepatic jaundice (C) 50 mg of bilirubin (D) 70 mg of bilirubin (C) Obstructive jaundice 253. Variable regions are present in (D) All of these (A) Immunoglobulins 246. Bile pigments are not present in urine in (B) α-Chains of T cell receptors (A) Haemolytic jaundice (C) β-Chains of T cell receptors (B) Hepatic jaundice (D) All of these (C) Obstructive jaundice 254. The total amount of calcium in an average (D) Rotor’s syndrome adult man is about 247. Serum alkaline phosphatase is greatly (A) 100 gm (B) 500 gm increased in (C) 1 kg (D) 10 kg (A) Haemolytic jaundice 255. The following proportion of the total body (B) Hepatic jaundice calcium is present in bones and teeth: (C) Obstructive jaundice (A) 75% (B) 90% (D) None of these (C) 95% (D) 99% 248. The active transport system for hepatic 256. The normal range of plasma calcium is uptake of bilirubin is congenitally (A) 3-5 mg/dl (B) 5-10 mg/dl defective in (C) 9-11 mg/dl (D) 11-15 mg/dl (A) Gilbert’s disease 257. Which of the normal range of ionized (B) Crigler-Najjar syndrome calcium in plasma is (C) Rotor’s syndrome (A) 2-4 mg/dl (B) 2-4 mEq/L (D) Dubin-Johnson syndrome (C) 4-5 mg/dl (D) 4-5 mEq/L 196 MCQs IN BIOCHEMISTRY

258. Tetany can occur in 266. Hypocalcaemia can occur in all the follow- ing except (A) Hypocalcaemia (B) Hypercalcaemia (A) Rickets (C) Alkalosis (B) Osteomalacia (D) Hypocalcaemia and alkalosis (C) Hyperparathyroidism (D) Intestinal malabsorption 259. Intestinal absorption of calcium occurs by 267. The major calcium salt in bones is (A) Active takeup (B) Simple diffusion (A) Calcium carbonate (C) Facilitated diffusion (B) Calcium chloride (D) Endocytosis (C) Calcium hydroxide (D) Calcium phosphate 260. Intestinal absorption of calcium is hampered by 268. The correct statement about serum inorganic phosphorous concentration is (A) Phosphate (B) Phytate (C) Proteins (D) Lactose (A) It is higher in men than in women (B) It is higher in women than in men 261. Calcitriol facilitates calcium absorption by increasing the synthesis of the following (C) It is higher in adults than in children in intestinal mucosa: (D) It is higher in children than in adults (A) Calcium Binding Protein 269. The product of serum calcium concentra- (B) Alkaline Phosphatase tion (mg/dl) and serum inorganic phos- (C) Calcium-dependent ATPase phorous concentration (mg/dl) in adults (D) All of these is about (A) 30 (B) 40 262. A high plasma calcium level decreases intestinal absorption of calcium by (C) 50 (D) 60 (A) Stimulating the secretion of parathormone 270. The product of serum calcium concentra- (B) Inhibiting the secretion of parathormone tion (mg/dl) and serum inorganic phos- phorous concentration (mg/dl) in children (C) Decreasing the synthesis of cholecalciferol is about (D) Inhibiting the secretion of thyrocalcitonin (A) 30 (B) 40 263. The daily calcium requirement of an adult (C) 50 (D) 60 man is about (A) 400 mg (B) 600 mg 271. The product of serum calcium concentration (mg/dl) and serum inorganic phosphorous (C) 800 mg (D) 1,000 mg concentration (mg/dl) is decreased in 264. The daily calcium requirement in preg- (A) Rickets nancy and lactation is about (B) Hypoparathyroidism (A) 600 mg (B) 800 mg (C) Hyperparathyroidism (C) 1,200 mg (D) 1,500 mg (D) Renal failure 265. Hypercalcaemia can occur in all the fol- 272. Serum inorganic phosphorous rises in all lowing except the following conditions except (A) Hyperparathyroidism (A) Hypoparathyroidism (B) Hypervitaminosis D (B) Hypervitaminosis D (C) Milk alkali syndrome (C) Chronic renal failure (D) Nephrotic syndrome (D) After a carbohydrate-rich meal MINERAL METABOLISM 197

273. Serum inorganic phosphorous decreases 282. Serum potassium level decreases in in all the following conditions except (A) Familial periodic paralysis (A) Hyperparathyroidism (B) Addison’s disease (B) Intestinal malabsorption (C) Renal failure (C) Osteomalacia (D) All of these (D) Chronic renal failure 283. Concentration of the following is higher 274. Serum magnesium level ranges between in intracellular fluid than in extracellular (A) 2–3 mg/dl (B) 3–5 mg/dl fluid: (C) 6–8 mg/dl (D) 9–11 mg/dl (A) Sodium (B) Potassium 275. Magnesium ions are required in the (C) Chloride (D) Bicarbonate reactions involving 284. Normal range of serum potassium is (A) NAD (B) FAD (A) 2.1-3.4 mEq/L (B) 3.5-5.3 mEq/L (C) ATP (D) CoA (C) 5.4–7.4 mEq/L (D) 7.5–9.5 mEq/L 276. Normal range of serum sodium is 285. Normal range of serum chloride is (A) 30–70 mEq/L (B) 70–110 mEq/L (A) 24–27 mEq/L (B) 70–80 mEq/L (C) 117–135 mEq/L (D) 136–145 mEq/L (C) 100–106 mEq/L (D) 120–140 mEq/L 277. Sodium is involved in the active uptake 286. An extracellular fluid having a higher of concentration of chloride than serum is (A) D-Glucose (B) D-Galactose (A) Bile (B) Sweat (C) L-Amino acids (D) All of these (C) CSF (D) Pancreatic juice 278. Aldosterone increases reabsorption of 287 Total amount of iron in an adult man is sodium in about (A) Proximal convoluted tubules (A) 1–2 gm (B) 2–3 gm (B) Ascending limb of loop of Henle (C) 3–4 gm (D) 6–7 gm (C) Descending limb of loop of Henle (D) Distal convoluted tubules 288. Haemoglobin contains about 279. Restriction of sodium intake is commonly (A) 30% of the total body iron advised in (B) 50% of the total body iron (A) Addison’s disease (B) Diarrhoea (C) 75% of the total body iron (C) Hypertension (D) None of these (D) 90% of the total body iron 280. Serum sodium level rises in all of the 289. About 5% of the total body, iron is present following except in (A) Renal failure (A) Transferrin (B) Myoglobin (B) Prolonged steroid therapy (C) Cytochromes (D) Haemosiderin (C) Aldosteronism 290. Each haemoglobin molecule contains (D) Dehydration (A) One iron atom (B) Two iron atoms 281. Hyponatraemia occurs in the following (C) Four iron atoms (D) Six iron atoms condition: 291. Each myoglobin molecule contains (A) Addison’s disease (B) Chronic renal failure (C) Severe diarrhoea (D) All of these (A) One iron atom (B) Two iron atoms (C) Four iron atoms (D) Six iron atoms 198 MCQs IN BIOCHEMISTRY

292. Apoferritin molecule is made up of 302. Daily iron requirement of an adult man (A) Four subunits (B) Eight subunits is about (C) Ten subunits (D) Twenty-four subunits (A) 1 mg (B) 5 mg (C) 10 mg (D) 18 mg 293. Ferritin is present in (A) Intestinal mucosa (B) Liver 303. Daily iron requirement of a woman of reproductive age is about (C) Spleen (D) All of these (A) 1 mg (B) 2 mg 294. Iron is stored in the form of (C) 10 mg (D) 20 mg (A) Ferritin and transferrin 304. All the following are good sources of iron (B) Transferrin and haemosiderin except (C) Haemoglobin and myoglobin (A) Milk (B) Meat (D) Ferritin and haemosiderin (C) Liver (D) Kidney 295. Iron is transported in blood in the form 305. Relatively more iron is absorbed from of (A) Green leafy vegetables (A) Ferritin (B) Haemosiderin (B) Fruits (C) Transferrin (D) Haemoglobin (C) Whole grain cereals 296. Molecular weight of transferrin is about (D) Organ meats (A) 40,000 (B) 60,000 306. Iron absorption from a mixed diet is about (C) 80,000 (D) 1,00,000 (A) 1–5 % (B) 5–10 % 297. Normal plasma iron level is (C) 20–25 % (D) 25–50 % (A) 50100 µg/dl (B) 100150 µg/dl 307. Iron deficiency causes (C) 50175 µg/dl (D) 250400 µg/dl (A) Normocytic anaemia 298. Iron is present in all the following except (B) Microcytic anaemia (A) Peroxidase (B) Xanthine oxidase (C) Megaloblastic anaemia (C) Aconitase (D) Fumarase (D) Pernicious anaemia 299. Total daily iron loss of an adult man is 308. Prolonged and severe iron deficiency can about cause astrophy of epithelium of (A) 0.1 mg (B) 1 mg (A) Oral cavity (B) Oesophagus (C) 5 mg (D) 10 mg (C) Stomach (D) All of these 300. Iron absorption is hampered by 309. All of the following statements about (A) Ascorbic acid (B) Succinic acid bronzed diabetes are true except (C) Phytic acid (D) Amino acid (A) It is caused by excessive intake of copper 301. Iron absorption is hampered by (B) Skin becomes pigmented (C) There is damage to cells of Islets of Langerhans (A) In achlorhydria β (D) Liver is damaged (B) When ferritin content of intestinal mucosa is low 310. The total amount of iodine in the body of (C) When saturation of plasma transferring is low an average adult is (A) 10–15 mg (B) 20–25 mg (D) When erythropoietic activity is increased (C) 45–50 mg (D) 75–100 mg MINERAL METABOLISM 199

311. Iodine content of thyroid gland in an 320. All the following statements about adult is about Wilson’s disease are correct except (A) 1–3 mg (B) 4–8 mg (A) It is a genetic disease (C) 10–15 mg (D) 25–30 mg (B) The defect involves copper-dependent P-type ATPase 312. Daily iodine requirement of an adult is about (C) Copper is deposited in liver, basal ganglia and around cornea (A) 50 µg (B) 100 µg (D) Plasma copper level is increased in it (C) 150 µg (D) 1 mg 321. Which of the following statements about 313. Consumption of iodised salt is recom- Menke’s disease are true. mended in (A) It is an inherited disorder of copper metabolism (A) Patients with hyperthyroidism (B) It occurs only in males (B) Patients with hypothyroidism (C) Plasma copper is increased in it (C) Pregnant women (D) Hair becomes steely and kinky in it (D) Goitre belt areas 322. The total amount of zinc in an average 314. All the following statements about adult is endemic goiter are true except (A) 0.25–0.5 gm (B) 0.5–1.0 gm (A) It occurs in areas where soil and water have low iodine content (C) 1.5–2.0 gm (D) 2.5–5.0 gm (B) It leads to enlargement of thyroid gland 323. Plasma zinc level is (C) It results ultimately in hyperthyroidism (A) 10–50 µg/dl (B) 50–150 µg/dl (D) It can be prevented by consumption of (C) 150–250 µg/dl (D) 250–500 µg/dl iodised salt 324. Zinc is a cofactor for 315. The total amount of copper in the body of an average adult is (A) Acid phosphatase (A) 1 gm (B) 500 mg (B) Alkaline phosphatase (C) 100 mg (D) 10 mg (C) Amylase (D) Lipase 316. The normal range of plasma copper is (A) 25–50 µg/dl (B) 50–100 µg/dl 325. Zinc is involved in storage and release of (C) 100–200 µg/dl (D) 200–400 µg/dl (A) Histamine (B) Acetylcholine (C) Epinephrine (D) Insulin 317. Copper deficiency can cause (A) Polycythaemia (B) Leukocytopenia 326. Intestinal absorption of zinc is retarded by (C) Thrombocytopenia (D) Microcytic anaemia (A) Calcium (B) Cadmium 318. Daily requirement of copper in adults is (C) Phytate (D) All of these about (A) 0.5 mg (B) 1 mg 327. The daily zinc requirement of an average (C) 2.5 mg (D) 5 mg adult is (A) 5 mg (B) 10 mg 319. All the following statements about ceruloplasmin are correct except (C) 15 mg (D) 25 mg (A) It is a copper-containing protein 328. Zinc deficiency occurs commonly in (B) It possesses oxidase activity (A) Acrodermatitis enteropathica (C) It is synthesised in intestinal mucosa (B) Wilson’s disease (D) Its plasma level is decreased inWilson’s (C) Xeroderma pigmentosum disease (D) Menke’s disease 200 MCQs IN BIOCHEMISTRY

329. Hypogonadism can occur in deficiency of 340. 1 kcal is roughly equal to (A) Copper (B) Chromium (A) 4.2 J (B) 42 J (C) Zinc (D) Manganese (C) 4.2 KJ (D) 42 KJ 330. Healing of wounds may be impaired in 341. Calorific value of proteins as determined deficiency of in a bomb calorimeter is (A) Selenium (B) Copper (A) 4 kcal/gm (B) 4.8 kcal/gm (C) Zinc (D) Cobalt (C) 5.4 kcal/gm (D) 5.8 kcal/gm 331. Hypochromic microcytic anaemia can occur in 342. Calorific value of proteins in a living per- (A) Zinc (B) Copper son is less than that in a bomb calorime- (C) Manganese (D) None of these ter because 332. The daily requirement for manganese in (A) Digestion and absorption of proteins is less adults is about than 100% (A) 1–2 mg (B) 2–5 mg (B) Respiratory quotient of proteins is less than 1 (C) 2–5 µg (D) 5–20 µg (C) Specific dynamic action of proteins is high (D) Proteins are not completely oxidized in living 333. Molybdenum is a cofactor for persons (A) Xanthine oxidase (B) Aldehyde oxidase (C) Sulphite oxidase (D) All of these 343. Calorific value of alcohol is 334. A trace element having antioxidant (A) 4 kcal/gm (B) 5.4 kcal/gm function is (C) 7 kcal/gm (D) 9 kcal/gm (A) Selenium (B) Tocopherol 344. Energy expenditure of a person can be (C) Chromium (D) Molybdenum measured by 335. Selenium is a constituent of (A) Bomb calorimetry (A) (B) Direct calorimetry (B) Glutathione peroxidase (C) Indirect calorimetry (C) Catalase (D) Direct or indirect calorimetry (D) Superoxide dismutase 345. Respiratory quotient of carbohydrates is 336. Selenium decreases the requirement of about (A) Copper (B) Zinc (A) 0.5 (B) 0.7 (C) Vitamin D (D) Vitamin E (C) 0.8 (D) 1.0 337. Upper safe limit of fluorine in water is 346. Respiratory quotient of fats is about (A) 0.4 ppm (B) 0.8 ppm (C) 1.2 ppm (D) 2 ppm (A) 0.5 (B) 0.7 (C) 0.8 (D) 1.0 338. The daily fluoride intake should not exceed 347. Respiratory quotient of proteins is about (A) 0.5 mg (B) 1 mg (A) 0.5 (B) 0.7 (C) 2 mg (D) 3 mg (C) 0.8 (D) 1.0 339. In adults, water constitutes about 348. Respiratory quotient of an average mixed (A) 50% of body weight diet is about (B) 55% of body weight (A) 0.65 (B) 0.7 (C) 60% of body weight (D) 75% of body weight (C) 0.75 (D) 0.85 MINERAL METABOLISM 201

349. At a respiratory quotient of 0.85, every 359. All following are essential trace elements litre of oxygen consumed represents an except energy expenditure of (A) Iron (B) Iodine (A) 5.825 kcal (B) 4.825 kcal (C) Zinc (D) Cadmium (C) 3.825 kcal (D) 2.825 kcal 360. Maximum quantity of sodium is excreted 350. BMR of healthy adult men is about through (A) 30 kcal/hour/square metre (A) Urine (B) Faeces (B) 35 kcal/hour/square metre (C) Sweat (D) None of these (C) 40 kcal/hour/square metre 361. All followings are rich sources of (D) 45 kcal/hour/square metre magnesium, except 351. BMR of healthy adult women is about (A) Milk (B) Eggs (A) 32 kcal/hour/square metre (C) Meat (D) Cabbage (B) 36 kcal/hour/square metre 362. All followings are poor sources of iron (C) 40 kcal/hour/square metre except (D) 44 kcal/hour/square metre (A) Milk (B) Potatoes 352. BMR is higher in (C) Wheat flour (D) Liver (A) Adults than in children 363. The Iron deficient children, absorption of (B) Men than in women Iron from GIT is (C) Vegetarians than in non-vegetarians (A) Unaltered (D) Warmer climate than in colder climate (B) Double than in normal child 353. BMR is decreased in (C) Manifold than in normal child (A) Pregnancy (B) Starvation (D) Lesser than in normal child (C) Anaemia (D) Fever 364. Main source of fluoride for human beings 354. BMR is increased in is (A) Starvation (B) Hypothyroidism (A) Milk (B) Water (C) Addison’s disease (D) Pregnancy (C) Vegetables (D) Eggs 355. BMR is decreased in all of the following 365. Quantity of copper present in the body except of an adult is (A) Fever (B) Addison’s disease (A) 0–50 mg (B) 50–100 mg (C) Starvation (D) Hypothyroidism (C) 100–150 mg (D) 150–250 mg 356. BMR is increased in all of the following 366. A level of 310–340 mg per 1000 ml of except blood is normal for the (A) Hyperthyroidism (B) Anaemia (A) Copper (B) Iron (C) Addison’s disease (D) Pregnancy (C) Potassium (D) Sodium 357. Specific dynamic action of carbohydrates 367. Daily requirement of phosphorous for an is about infant is (A) 5% (B) 13% (A) 240–400 mg (B) 1.2 gms (C) 20% (D) 30% (C) 800 mg (D) 800–1200 mg 358. Specific dynamic action of proteins is 368. Maximum quantity of Zinc is present in about the body in (A) 5% (B) 13% (A) Prostate (B) Choroid (C) 20% (D) 30% (C) Skin (D) Bones 202 MCQs IN BIOCHEMISTRY

369. Average concentration of chloride ions in 378. A deficiency of copper effects the formation cerebrospinal fluid per 100 ml is of normal collagen by reducing the activity (A) 40 mg (B) 440 mg of which of the following enzyme? (C) 160 mg (D) 365 mg (A) Prolyl hydroxylase 370. Total iron content of the normal adult is (B) Lysyl oxidase (C) Lysyl hydroxylase (A) 1-2 gm (B) 3-4 gm (D) Glucosyl transferase (C) 4-5 gm (D) 7-10 gm 379. Molecular iron (Fe) is 371. Absorption of phosphorous from diet is favoured by (A) Stored primarily in spleen (A) Moderate amount of fat (B) Absorbed in the intestine (B) Acidic environment (C) Absorbed in the ferric, Fe+++ form (C) High calcium content (D) Stored in the body in combination with ferritin (D) High phytic acid 380. All the following statements regarding 372. Daily intake of potassium for a normal calcium are correct except person should be (A) It diffuses as a divalent cation (A) 1 gm (B) 2 gm (B) It freely diffuses across the endoplasmic (C) 3 gm (D) 4 gm reticulum of muscle cells (C) It can exist in the blood as ionic form and 373. Absorption of calcium decreases if there also protein bound is high concentration in the diet of (D) It is found in high concentration in bones (A) Copper (B) Sodium (C) Magnesium (D) Cadmium 381. Iron is absorbed from 374. Of the following highest concentration of (A) Stomach calcium is seen in (B) Duodenum and jejunum (A) Blood (B) CSF (C) Ileum (C) Muscle (D) Nerve (D) Noen of the above 375. Cobalt is essential component of 382. The normal route of calcium excretion is

(A) Vitamin B1 (B) Vitamin B6 (A) Kidney

(C) Vitamin B12 (D) All of these (B) Kidney and Liver 376. Iodine is required in human body for (C) Kidney and Intestine (D) Kidney, Intestine and Pancreas (A) Formation of thyroxine (B) Formation of Glutathione 383. Hypocalcaemia affects (C) Formation of potassium iodide (A) Skeletal muslces (D) Adrenalin (B) Smooth muscles 377. A hypochromic necrocytic anaemia with (C) Cardiac muscles increase Fe stores in the bone marrow (D) Skeletal muscles + smooth muscles + cardiac may be muscles

(A) Folic acid responsive 384. Transferrin is a type of (B) Vitamin B responsive 12 (A) Albumin (B) α-globulin (C) Pyridoxine responsive (C) β globulin (D) γ-globulin (D) Vitamin C responsive 1 MINERAL METABOLISM 203

385. In case of wilson’s disease, the features 393. Which of the following is true? Hypochro- include all of the following except mic anaemia is not due to iron deficiency (A) Progressive hepatic cirrhosis except (B) Keyser Fleisher ring (A) Serum ‘Fe’ is high (C) Aminoaciduria (B) Normal/low transferrin (D) Urinary excretion of Cu is decreased (C) Stainable iron in bone marrow 386. In Vitamin D poisoning (hyper-vitaminosis) (D) Iron therapy is affective (A) Both serum and urinary “Ca” 394. Cytosolic superoxide dismutase contains (B) The serum Ca is low and urinary calcium high (A) Zn only (B) Cu only (C) The serum “Ca” is increased and urinary (C) Zn and Cu (D) Mn “Ca” is normal 395. A rise in blood ‘Ca’ may indicate (D) Both serum and urinary “Ca” are low (A) Paget’s disease (B) Vitamin D deficiency 387. The % of ‘K’ in Extracellular fluid is about (C) Cushing’s disease (D) Hypervitaminosis D (A) 1% (B) 2 to 3% (C) 10% (D) 15% 396. The essential trace element which cata- lyzes the formation of Hb in the body is 388. The Fe containing pigments is (A) Mn (B) Se (A) Haematoidin (B) Bilirubin (C) Mg (D) Cu (C) Hemasiderin (D) Urobilinogen 397. Zinc is a constituent of the enzyme: 389. All of the following are true of Wilson’s disease except (A) Succinate dehydrogenase (B) Carbonic anhydrase (A) Low total plasma Cu (C) Mitochondrial superoxide dismutase (B) Elevated urinary copper (D) Aldolase (C) Arthritis (D) Aminoaciduria 398. The active transport of ‘Ca’ is regulated by ______which is synthesized in 390. An increased serum ‘Iron’ and decreased kidnyes. ‘Fe’ binding capacity are found in (A) Cholecalciferol (A) Fe-deficiency anaemia (B) Ergosterol (B) Sideroblastic anaemia (C) 25-OH cholecalciferol (C) Thalassaemia (D) 1, 25-di OH-Cholecalciferol (D) Anaemia of chromic disorders 391. Iron therapy is ineffective in which of the 399. Ceruloplasmin shows the activity following conditions: (A) As ferroxidase (B) As reductase (A) Chronic blood loss (C) As ligase (D) As transferase (B) Inadequate Fe intake 400. The principal cation of extra cellular fluid: (C) Hypochromic anaemia of pregnancy (A) K+ (B) Na+ (D) Thalassaemia minor (C) H+ (D) Ca2+ 392. In hoemochromatosis, the liver is infiltrat- 401. What is the principal cation of intracellular ed with fluid? (A) Copper (B) Iron (A) K+ (B) Na+ (C) Manganese (D) Chromium (C) Ca2+ (D) Mg2+ 204 MCQs IN BIOCHEMISTRY

402. What is the normal level of K+ in the serum ? (C) It is the stored form of iron (A) 137–148 mEq/L (B) 120–160 mEq/L (D) Non-protein moiety (C) 3.9–5.0 mEq/L (D) 0.3–0.59 mEq/L 409. What is ceruloplasmin? 403. The general functions of minerals are (A) Plasma protein (B) Stored form of copper (A) The structural components of body tissues (C) Both A and B (D) None of these (B) In the regulation of body fluids 410. The following are the functions of copper: (C) In acid-base balance (A) Constituent of cytochromes (D) All of these (B) Catalase 404. What are the functions of potassium? (C) Tyrosinase (A) In muscle contraction (D) All of these (B) Cell membrane function 411. Zn is present as prosthetic group in this (C) Enzyme action enzyme: (D) All of these (A) Carbonic anhydrase 405. The daily requirement of calcium is (B) Carboxy peptidase (A) 200 mg (B) 400 mg (C) Lactate dehydrogenase (C) 800 mg (D) 600 mg (D) All of these 406. The normal serum inorganic phosphorous 412. Fluorosis is caused due to level is (A) Excessive intake of fluorine (A) 1.5–2.5 mg/100 ml (B) Low intake of fluorine (B) 2.5–4.5 mg/100 ml (C) Discoloration of the teeth due to low intake (C) 4.5–6.5 mg/100 ml (D) All of these (D) 0.5–1.5 mg/100 ml 413. What is the state of iron in transferrin? 407. When phosphorous level is lowered ? (A) Ferrous form (B) Ferric form (A) In hyper thyroidism (B) Cirrosis of liver (C) Both A and B (D) None of these (C) Leukemia (D) Hypothyroidism 414. Haemoglobin formation needs both 408. Ferritin is (A) Iron and Zinc (B) Iron and Calcium (A) Coenzyme (C) Iron and Copper (D) Iron and Magnesium (B) One of the component of photophosphorylation MINERAL METABOLISM 205

ANSWERS 1. A 2. C 3. C 4. A 5. B 6. B 7. C 8. B 9. C 10. D 11. C 12. C 13. B 14. A 15. B 16. A 17. B 18. D 19. D 20. A 21. A 22. A 23. C 24. B 25. C 26. C 27. A 28. C 29. C 30. A 31. D 32. A 33. D 34. A 35. B 36. D 37. B 38. C 39. A 40. A 41. B 42. A 43. D 44. A 45. B 46. A 47. A 48. D 49. D 50. A 51. D 52. A 53. A 54. A 55. D 56. B 57. B 58. A 59. C 60. D 61. A 62. D 63. D 64. D 65. B 66. D 67. D 68. D 69. C 70. D 71. A 72. B 73. C 74. D 75. D 76. B 77. A 78. C 79. A 80. D 81. A 82. A 83. C 84. A 85. C 86. D 87. A 88. C 89. D 90. D 91. C 92. B 93. D 94. C 95. B 96. C 97. B 98. A 99. D 100. A 101. C 102. A 103. B 104. B 105. A 106. D 107. C 108. B 109. A 110. D 111. C 112. D 113. A 114. B 115. A 116. A 117. D 118. A 119. D 120. D 121. B 122. A 123. A 124. B 125. A 126. A 127. A 128. C 129. A 130. A 131. B 132. C 133. D 134. C 135. C 136. C 137. A 138. B 139. A 140. B 141. A 142. D 143. C 144. C 145. D 146. D 147. B 148. D 149. C 150. D 151. C 152. C 153. B 154. D 155. A 156. C 157. D 158. B 159. A 160. D 161. C 162. D 163. A 164. C 165. C 166. A 167. A 168. D 169. A 170. D 171. A 172. A 173. A 174. A 175. B 176. A 177. A 178. C 179. A 180. C 181. D 182. B 183. A 184. D 185. C 186. A 187. B 188. C 189. B 190. C 191. C 192. D 193. A 194. D 195. D 196. D 197. A 198. A 199. A 200. C 201. B 202. A 203. D 204. A 205. A 206. B 207. C 208. D 209. B 210. C 211. A 212. C 213. B 214. A 215. B 216. A 217. A 218. A 219. B 220. D 221. A 222. A 223. B 224. D 225. B 226. A 227. C 228. A 229. C 230. A 231. C 232. B 233. C 234. D 235. A 236. C 237. A 238. B 239. A 240. B 241. D 242. B 243. A 244. A 245. A 246. A 247. C 248. A 249. A 250. D 251. D 252. B 206 MCQs IN BIOCHEMISTRY

253. D 254. C 255. D 256. C 257. C 258. D 259. A 260. B 261. D 262. B 263. C 264. C 265. D 266. C 267. D 268. D 269. A 270. C 271. A 272. D 273. D 274. A 275. C 276. D 277. D 278. D 279. C 280. A 281. D 282. A 283. B 284. B 285. C 286. C 287. C 288. C 289. B 290. C 291. A 292. D 293. D 294. D 295. C 296. C 297. C 298. D 299. B 300. C 301. A 302. C 303. D 304. A 305. D 306. B 307. B 308. D 309. A 310. C 311. C 312. C 313. D 314. C 315. C 316. C 317. D 318. C 319. C 320. D 321. C 322. C 323. B 324. B 325. D 326. D 327. C 328. D 329. C 330. C 331. B 332. B 333. D 334. A 335. B 336. D 337. C 338. D 339. C 340. C 341. C 342. D 343. C 344. D 345. D 346. B 347. C 348. D 349. B 350. C 351. B 352. B 353. B 354. D 355. A 356. C 357. A 358. D 359. D 360. A 361. C 362. D 363. B 364. B 365. C 366. D 367. A 368. C 369. B 370. C 371. B 372. D 373. C 374. C 375. C 376. A 377. C 378. B 379. D 380. B 381. B 382. C 383. D 384. B 385. D 386. A 387. A 388. C 389. C 390. B 391. D 392. B 393. D 394. C 395. D 396. D 397. B 398. D 399. A 400. B 401. A 402. C 403. D 404. D 405. C 406. B 407. A 408. C 409. C 410. D 411. D 412. A 413. B 414. C HORMONE METABOLISM 207

CHAPTER 8

HHHORMONEORMONEORMONE MMMETETETABOLISMABOLISMABOLISM

1. Hormones 6. The number of amino acids in human (A) Act as coenzyme growth hormone is (B) Act as enzyme (A) 91 (B) 151 (C) Influence synthesis of enzymes (C) 191 (D) 291 (D) Belong to B-complex group 7. Growth hormone causes hyperglycemia. 2. Hormone that binds to intracellular It is a result of receptor is (A) Decreased peripheral utilization of glucose (A) Adrenocorticotropic hormone (B) Decreased hepatic production via gluconeo- (B) Thyroxine genesis (C) Follicle stimulating hormone (C) Increased glycolysis in muscle (D) Glucagon (D) Decrersed lipolysis 3. Hormone that bind to cell surface receptor 8. Acromegaly results due to excessive and require the second messenger camp release of is (A) Thyroxine (B) Growth hormone (A) Antidiuretic hormone (C) Insulin (D) Glucagon (B) Cholecystokinin 9. Growth hormone is released by (C) Calcitriol (D) Gastrin (A) Somatostatin (B) Growth hormone releasing hormone 4. A hormone secreted from anterior pituitary (C) Prolactin release inhibiting hormone is (D) Luteinizing releasing hormone (A) Growth hormone (B) Vasopressin (C) Oxytocin (D) Epinephrine 10. The number of amino acids in prolactin is (A) 134 (B) 146 5. A hormone secreted from posterior pituitary is (C) 172 (D) 199 (A) Vasopressin 11. Adrenocorticotropic hormone (ACTH) is a (B) Thyrotropic hormone single polypeptide containing (C) Prolactin (A) 25 amino acid (B) 39 amino acid (D) Adrenocorticotropic hormone (C) 49 amino acid (D) 52 amino acid 208 MCQs IN BIOCHEMISTRY

12. Biological activity of ACTH requires 20. A specific cortisol binding protein, trans- (A) 10-N-terminal amino acid cortin is a (B) 24-N-terminal amino acid (A) Albumin (B) α1-Globulin (C) 24-C-terminal amino acid (C) α2-Globulin (D) β-Globulin (D) 15-C-terminal amino acid 21. Cortisol is synthesized in 13. ACTH stimulates the secretion of (A) Zona fasiculata (B) Zona glomerulosa (C) Zona reticularis (D) Chromaffin cells (A) Glucocorticoids (B) Epinephrine (C) Thyroxine (D) Luteinizing hormone 22. All mammalian steroid hormones are formed from 14. Excessive secretion of ACTH causes (A) Purine (B) Pyrimidine (A) Cushing’s syndrome (C) Cholesterol (D) Pyrrole (B) Addison’s disease (C) Myxoedema 23. A very efficient inhibitor of steroid biosynthesis is (D) Thyrotoxicosis (A) Aminoglutethimide 15. In Cushing’s syndrome-a tumour associ- (B) Aminoimidazole ated disease of adrenal cortex, there is (C) Aminoimidazolesuccinyl carboxamine (A) Decreased epinephrine production (D) Aminopterin (B) Excessive cortisol production 24. In adrenal gland the cholesterol is stored (C) Excessive epinephrine production (A) Mostly in the free form (D) Decreased cortsoil production (B) Mostly in esterified form 16. ACTH induces rise in (C) Large amount of free form and less amount (A) Cyclic AMP (B) Cyclic GMP of esterified form (C) Calcium (D) Magnesium (D) Equal amounts of free and esterified form 17. The circulating concentration of ACTH in 25. Aldosterone synthesis occurs in plasma is (A) Zona reticularis (B) Zona fasciculata (A) 0.05 m µ /100 ml (C) Zona glomerulosa (D) Chromaffian cells (B) 0.1–2.0 m µ /100 ml 26. In the biosynthesis of cortiol, the sequence (C) 2.5–3.5 m µ /100 ml of enzymes involved is (D) 3.0–5.0 m µ /100 ml (A) Hydroxylase–dehydrogenase + isomerase – hydroxylase 18. Hyperglycemic effect of glucocorticoids is due to (B) Dehydrogenase–hydroxylase–isomerase (C) Hydroxylase–lyase–dehydrogenase isomerase (A) Inactivation of (D) Isomerase–lyase–hydroxylase–dehydro- (B) Inactivation of fructose 1,6-biphosphatase genase (C) Stimulation of synthesis of pyruvate carboxylase 27. The defect in adrenal cortex responsible (D) Stimulation of synthesis of eltroxykinase for lack of glucocorticoids and mineralcor- 19. The predominant glucocorticoid is ticoids is (A) Cortisol (A) Androstenedione deficiency (B) Aldosterone (B) 17 α -OH progesterone deficiency (C) Dehydroephiandrosterone (C) C-21 hydroxylase deficiency (D) Androstenedione (D) Testosterone deficiency HORMONE METABOLISM 209

28. 3-βββ-Hydroxysteroid dehydrogenase and 36. Catecholamine hormones are ∆∆5,4 isomerase catalyse the conversion of ∆∆∆ (A) 3, 4-Dihydroxy derivatives of phenylethylamine the weak androgen DHEA to (B) p-Hydroxy derivatives of phenylacetate (A) Androstenedione (B) Testosterone (C) p-Hydroxy derivatives of phenylpyruvate (C) Progesterone (D) Estrone (D) p-Hydroxy derivatives of phenyllactate 29. In the resting state plasma concentration of cortisol is 37. The sequential steps in the conversion of tyrosine to epinephrine are (A) 0.4–2.0 µg/100 ml (B) 2.0–4.0 µg/100 ml (A) Ring hydroxylation-decarboxylation-side chain (C) 5.0–15.0 µg/100 ml hydroxylation-N-methylation (D) 18.0–25.0 µg/100 ml (B) Side chain hydroxylation-decarboxylation-ring hydroxylation N-methylation 30. The most important effect of aldosterone is to (C) Decarboxylation-ring hydroxylation-side chain hydroxylation-N-methylation (A) Increase the rate of tubular reabsorption of sodium (D) N-methylation-decarboxylation-ring and side chain hydroxylation (B) Decrease the rate of tubular reabsorption of potassium 38. The hormone required for uterine muscle (C) Decrease the reabsorption of chloride contraction for child birth is (D) Decrease the renal reabsorption of sodium (A) Progesterone (B) Estrogen 31. One of the potent stimulators of (C) Oxytocin (D) Vasopressin aldosterone secretion is 39. The number of amino acids in the hormone (A) Increased sodium concentration oxytocin is (B) Decreased potassium concentration (C) Increased potassium concentration (A) 7 (B) 9 (D) Increased ECF volume (C) 14 (D) 18 32. In the rennin-angiotensin system the 40. Vasopressin and oxytocin circulate un- primary hormone is bound to proteins and have very short (A) Angiotensinogen (B) Angiotensin I plasma half lives, on the order of (C) Angiotensin II (D) Angiotensin III (A) 1–2 minutes (B) 2–4 minutes (C) 5–8 minutes (D) 10–12 minutes 33. Aldosterone release is stimulated by

(A) α2-Globulin (B) Renin 41. Melanogenesis is stimulated by (C) Angiotensin II (D) Growth hormone (A) MSH (B) FSH 34. In the synthesis of Angiotensin I, rennin (C) LH (D) HCG acts on Angiotensinogen and cleaves the 42. The number of amino acids in antidiuretic (A) Leucine – leucine at 10 and 11 position hormone is (B) Valine – tyrosine at 3 and 4 position (A) 9 (B) 18 (C) Isoleucine – histidine at 5 and 6 position (C) 27 (D) 36 (D) Proline – histidine at 7 and 8 position 43. ADH 35. Catecholamine hormones are synthesized in the (A) Reabsorbs water from renal tubules (A) Chromaffin cells of adrenal medulla (B) Excretes water from renal tubules (B) Zona glomerulosa of adrenal cortex (C) Excretes hypotonic urine (C) Zona fasciculate of adrenal cortex (D) Causes low specific gravity of urine (D) Zona reticularis of adrenal cortex 210 MCQs IN BIOCHEMISTRY

44. Increased reabsorption of water from the 52. In the synthetic pathway of epinephrine, kidney is the major consequence of the disulfiram (antabuse) inhibits the secretion of the hormone? enzyme: (A) Cortisol (B) Insulin (A) Tyrosine hydroxylase (C) Vasopressin (D) Aldosterone (B) Dopamine β-hydroxylase 45. An increase in the osmolality of extracel- (C) DOPA decarboxylase lular compartment will (D) N-methyl transferase (A) Inhibit ADH secretion 53. The biosynthesis of both Catecholamine (B) Stimulate ADH secretion and serotonin require (C) Cause no change in ADH secretion (A) Tyrosine hydroxylase (D) Stimulate the volume and osmoreceptor and (B) N-methyl transferase inhibit ADH secretion (C) Aromatic amino acid decarboxylase 46. For Catecholamine biosynthesis the rate (D) Tryptophan pyrrolase limiting enzyme is 54. Epinephrine stimulates glycogenolysis in (A) DOPA decarboxylase (A) Liver (B) Muscle (B) DOPAMINE β-hydroxylase (C) Liver and muscle (D) Kidney (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase 55. A cup of strong coffee would be expected to 47. A hormone which cannot cross the blood (A) Interfere with the synthesis of prostaglandins brain barrier is (B) Decrease the effect of glucagon (A) Epinephrine (B) Aldosterone (C) Enhance the effect of epinephrine (C) ACTH (D) TSH (D) Provide the vitamin nicotinic acid 48. The plasma level of epinephrine is less 56. Epinephrine is derived from norepineph- than rine by (A) 0.1 ng/ml (B) 0.2 ng/ml (A) Decarboxylation (B) Hydroxylation (C) 0.4 ng/ml (D) 0.8 ng/ml (C) Oxidation (D) N-methylation 49. Epinephrine is rapidly metabolized by 57. 5 HIAA test is negative if patient is taking (A) Monoamine oxidase (A) Aspirin (B) Colchicine (B) Deaminase (C) Phenothiazone (D) Methotrexate (C) Transminase (D) Decarboxylase 58. Presence of significant amount of 5-HIAA in urine indicates 50. Pheochromocytomas are tumours of (A) Carcinoid in liver (A) Adrenal cortex (B) Adrenal medulla (B) Carcinoid in appendix (C) Pancreas (D) Bone (C) Metastasis of carcinoma of liver 51. A characteristic of pheochromocytoma is (D) Hepatoma elevated urinary excretion of 59. The normal serum level of triiodothyro- (A) Dopamine nine (T3) is (B) Tyrosine (A) 0.2–0.5 ng/ml (B) 0.7–2.0 ng/ml (C) Vinylmandelic acid (C) 2.0–4.0 ng/ml (D) 5.0–8.0 ng/ml (D) Phenylalanine HORMONE METABOLISM 211

60. The normal serum level of thyroxine (T4) 69. TSH stimulates the synthesis delete is (A) Thyroxine (B) Adrenocorticoids (A) 2.0–4.0 µg/100 ml (C) Epinephrine (D) Insulin (B) 5.5–13.5 µg/100 ml 70. Thyroid hormones are synthesized by the (C) 14.0–20.3 µg/100 ml iodination of the amino acid: (D) 20.0–25.0 µg/100 ml (A) Glycine (B) Phenylalanine 61. Excess secretion of thyroid hormones (C) Alanine (D) Tyrosine causes (A) Hyperthyroidism (B) Myxoedema 71. The tyrosine residues per molecule of (C) Cretinism (D) Cushing syndrome thyroglobulin is (A) 85 (B) 95 62. Insufficient free T3 and T4 results in (C) 115 (D) 135 (A) Grave’s disease (B) Mysoedema (C) Cushing syndrome (D) Gigantism 72. The percentage of inactive precursors (monoidotyrosine and diiodotyrosine) in 63. In primary hypothyroidism the useful thyroglobulin is estimation is of (A) 30 (B) 40 (A) T (B) T 3 4 (C) 50 (D) 70 (C) TBG (D) Autoantibodies 73. The number of amino acids in parathor- 64. When iodine supplies are sufficient the T 3 mone is and T4 ratio in thyroglobulin is (A) 1 : 2 (B) 1 : 4 (A) 65 (B) 84 (C) 1 : 7 (D) 1 : 10 (C) 115 (D) 122 65. A substance which competes with iodide 74. The sequence of amino acid in which the uptake mechanism by thyroid gland is biological value of parathormone is (A) Thiocynate (B) Iodoacetate (A) 1–15 (B) 1–34 (C) Fluoride (D) Fluoroacetate (C) 30–50 (D) 50–84 66. Thyroperoxidase enzyme contains 75. PTH (A) Heme (B) Copper (A) Reduces the renal clearance or excretion of (C) Zinc (D) Magnesium calcium (B) Increases renal phosphate clearance 67. Thyroproxidase requires hydrogen (C) Increases the renal clearance of calcium peroxide as oxidizing agent. The H2O2 is produced by (D) Decreases the renal phosphate clearance

(A) FADH2 dependent enzyme 76. The number of amino acids in the peptide (B) NADH dependent enzyme hormone calcitonin is (C) NADP dependent enzyme (A) 16 (B) 24 (D) NADPH dependent enzyme (C) 32 (D) 40 68. Thyroid stimulating hormone is a dimer. 77. Calcitonin causes The ααα-subunits of TSH, LH, FSH are identical. Thus the biological specificity (A) Calcinuria and phosphaturia must therefore be βββ subunit in which the (B) Decrease in urinary calcium number of amino acids is (C) Decrease in urinary phosphorous (A) 78 (B) 112 (D) Increase in blood calcium level (C) 130 (D) 199 212 MCQs IN BIOCHEMISTRY

78. The characteristic of hyperparathyroidism 86. In the B chain of insulin molecule, the N- is terminal amino acid is (A) Low serum calcium (A) Proline (B) Threonine (B) High serum phosphorous (C) Phenylalanine (D) Lysine (C) Low serum calcium and high serum phos- phorous 87. In the B chain of insulin molecule, the (D) High serum calcium and low serum C-terminal amino acid: phosphate (A) Threonine (B) Tyrosine 79. Parathyroid hormone (C) Glutamate (D) Valine (A) Is released when serum Ca++ is too high 88. In the insulin molecule, the number of (B) Inactivates vitamin D interchain disulphide brides is ++ (C) Is secreted when Ca is too low (A) 1 (B) 2 (D) Depends on vitamin K for adequate activity (C) 3 (D) 4 80. δδδ-Cells of islet of langerhans of pancreas δδ 89. In the insulin molecule, the number of produce intrachain disulphide bridges is (A) Pancreatic polypeptide (A) 1 (B) 2 (B) Pancreatic lipase (C) 3 (D) 4 (C) Somatostatin (D) Steapsin 90. Insulin exists in polymeric forms, for polymerization it requires 81. βββ-cells of islet of langerhans of the pancreas secrete (A) Calcium (B) Magnesium (A) Insulin (C) Manganese (D) Zinc (B) Glucagon 91. The number of amino acids in pre-pro (C) Somatostatin insulin is (D) Pancreatic polypeptide (A) 51 (B) 86 82. Target tissue of insulin is (C) 109 (D) 132 (A) Red blood cells 92. Proinsulin has (B) Renal tubular cells (A) 74 amino acids (B) 86 amino acids (C) GI tract epithelial cells (D) Liver (C) 105 amino acids (D) 109 amino acids 83. Insulin is a dimmer. The number of amino 93. Daily secretion of insulin in a normal adult acids in the A and B chain respectively is man is about (A) 19 and 28 (B) 21 and 30 (A) 10 units (B) 20 units (C) 25 and 35 (D) 29 and 38 (C) 30 units (D) 50 units

84. In A chain of the insulin molecule the N- 94. The insulin content of pancreas is about terminal amino acid is (A) 50–70 units (B) 100–150 units (A) Glycine (B) Valine (C) 150–180 units (D) 200–250 units (C) Serine (D) Phenylalanine 95. The half life of insulin is 85. In the A chain of insulin molecule the C- terminal amino acid is (A) < 3–5 minutes (B) < 8–10 minutes (A) Asparagine (B) Threonine (C) < 15 minutes (D) < 15 minutes (C) Valine (D) Tyrosine HORMONE METABOLISM 213

96. Insulin stimulates 103. Deficiency of insulin results in (A) Hepatic glycogenolysis (A) Rapid uptake of sugar (B) Hepatic glycogenesis (B) Low blood glucose level (C) Lipolysis (C) Decrease urine output (D) Gluconeogenesis (D) Presence of glucose in urine 97. Action of insulin on lipid metabolism is 104. The primary stimulus for insulin secretion is increased. (A) It increases lipolysis and increases triglyceride synthesis (A) Blood level of epinephrine (B) Blood level of glucagon (B) It decreases lipolysis and increases trigly- ceride synthesis (C) Blood level of glucose (C) It decreases lipolysis and decreases trigly- (D) Water intake ceride synthesis 105. The ααα-cells of pancreas islets produce (D) It increases synthesis of triglyceride and increa- (A) Insulin sed ketogenesis (B) Glucagon 98. Insulin increases the activity of (C) Somatostatin (A) Pyruvate kinase (D) Pancreatic polypeptide (B) Phosphorylase 106. The number of amino acids in single chain (C) Triacylglycerol kinase polypeptide glucagons is (D) Fructose 2, 6-bisphosphatase (A) 21 (B) 29 (C) 31 (D) 39 99. Insulin decreases the activity of (A) cAMP dependent protein kinase 107. The half life of glucagons is (B) HMG CoA-reductas (A) ~5 (B) ~7 (C) (C) ~10 (D) ~12 (D) Acetyl CoA-carboxylase 108. Glucagon enhances 100. The human insulin gene located on the (A) Hepatic glycogenolysis short arm of chromosome: (B) Muscle glycogenolysis (A) 11 (B) 17 (C) Hepatic glycogenesis (C) 18 (D) 20 (D) Lipogenesis 101. Normal serum insulin level varies 109. Normal serum glucagons level in fasting between state varies between (A) 0-–10 pg/ml (B) 20–100 pg/ml (A) 4–25 µU/ml (B) 25–50 µU/ml (C) 200–300 pg/ml (D) 400–500 pg/ml (C) 70–90 µU/ml (D) 100–120 µU /ml 110. Glucagon 102. Following is a normal overnight fast and a cup of black coffee, a diabetic woman (A) Increases protein synthesis feels slightly nausious and decides to skip (B) Inhibits lipolysis in adipocytes breakfast. However she does take her (C) Increases gluconeogenesis in liver shot of insulin. This may result in (D) Stimulates muscle glycogenolysis (A) Heightened glycogenolysis 111. Normal serum free testosterone in adult (B) Hypoglycemia men varies between (C) Increased lipolysis (A) 1–5 ng/dl (B) 6–9 ng/dl (D) Glycosuria (C) 10–30 ng/dl (D) 50–100 ng/dl 214 MCQs IN BIOCHEMISTRY

112. Normal serum free testosterone in adult 121. Serum progesterone level during preg- women varies between nancy is (A) 0.0–0.2 ng/dl (B) 0.3–2 ng/dl (A) < 12 ng/ml (B) > 12 ng/ml (C) 10–30 ng/dl (D) 50–100 ng/dl (C) < 20 ng/ml (D) >24 ng/ml 113. The prepubertal total serum testosterone 122. Serum progesterone level during luteal is phase is (A) <100 ng/100 ml (B) < 200 ng/100 ml (A) 0.2–203 ng/ml (B) 3.0–5.0 ng/ml (C) <300 ng/100 ml (D) < 400 ng/100 ml (C) 6.0–30 ng/ml (D) 750 ng/ml 114. The total serum testosterone in adult men 123. Androgens are produced by is (A) Cells of sertoli (A) 50–100 ng/100 ml (B) Leydig cells (B) 150–250 ng/100 ml (C) Rete testis (C) 300–1000 ng/100 ml (D) Efferent ductules (D) 1000–3000 ng/100 ml 124. The leyding cell activity is controlled by 115. The total serum testosterone in adult (A) Intestitial cell stimulating hormone women is (B) Adernocortex stimulating hormone (A) 0–5 ng/100 ml (C) Thyroid stimulating hormone (B) 10–15 ng/100 ml (D) Melanocyte stimulating harmone (C) 20–80 ng/100 ml 125. Stein-leventhal syndrome is due to over- (D) 100–200 ng/100 ml production of 116. The serum estradiol level in men is (A) Estrogens (B) Androgens (A) 0–5 pg/ml (B) 5–10 pg/ml (C) Gastogens (D) Ethinyl estradiol (C) 24–68 pg/ml (D) 40–60 pg/ml 126. The production of progesterone by corpus 117. The serum estradiol level in women during luteum cell is stimulated by 1–10 days of menstrual cycle is (A) LH (B) TSH (A) 0–10 pg/ml (B) 12–20 pg/ml (C) ACTH (D) MSH (C) 24–68 pg/ml (D) 80–100 pg/ml 127. In the biosynthesis of testosterone the 118. The serum estradiol level in women during rate limiting step is conversion of 11–20 days of menstrual cycle is (A) Cholesterol to pregnenolone (A) 5–30 pg/ml (B) 50–300 pg/ml (B) Pregnenolone to progesterone (C) 500–900 pg/ml (D) 1000 pg/ml (C) Progesterone to 17 α-hydroxy progesterone 119. The serum estradiol level in women during (D) 17 α-Hydroxy progesterone to androstene- 21–30 days of menstrual cycle is dione (A) 10-20 pg/ml (B) 22-66 pg/ml 128. The enzyme catalyzing conversion of an- (C) 73-149 pg/ml (D) 1000 pg/ml drostenedione to testosterone is a (A) Oxygenase (B) Dehydrogenase 120. The serum progesterone level in follicular (C) Isomerase (D) Decarboxylase phase is about (A) 0.2–1.5 ng/100 ml 129. Conversion of testosterone to estradiol (B) 2.0–2.5 ng/100 ml requires the enzyme: (C) 3.5–4.5 ng/100 ml (A) (B) Dehydrogenase (D) 5.0–6.5 ng/100 ml (C) Lyase (D) Isomerase HORMONE METABOLISM 215

130. The precursor of testosterone is 138. The only correct statement about hormone (A) Aldosterone (B) Methyl testosterone receptors is (C) Estrone (D) Pregnenolone (A) Receptors for protein hormones are present in cytosol 131. Urinary 17 ketosteroids (B) Receptors for steroid hormones are membrane (A) Are not found in women bound (B) Reflect the total production of androgenic (C) Hormone-receptor binding is irreversible substances (C) Indicate the total production of sex hormone (D) Receptors can undergo down regulation and up regulatoin (D) Are highly active androgens 139. Down regulation is 132. The hormone measured in urine to test pregnancy is (A) Increased destruction of a hormone (A) Anterior pituitary luteinizing hormone (B) Feed back inhibition of hormone secretion (B) Androgen (C) Decreased concentration of a hormone in (C) Progesterone blood (D) Choroinic gonadotropin (D) Decrease in number of receptors for a hormone 133. Total number of amino acids in human chorionic gonadotropin is 140. All the following statements about (A) 53 (B) 92 hormones are true except (C) 145 (D) 237 (A) All of them require specific carriers in plasma 134. A hormone produced by corpus luteum (B) All of them require specific receptors in target and placenta, concerned with relaxation cells of pelvis tissue is (C) Some of them are subject to feedback (A) HCG regulation (B) Chorionic somatommotropin (D) Some of them increase the transcription of (C) Relaxin certain genes (D) Progestins 141. All the following statements about steroid 135. Synthetic progesterone used in oral hormones are true except contraceptive is (A) They are hydrophobic (A) Norethindrone (B) Pregnenolone (B) They require carriers to transport them in (C) Androstenodione (D) Stilbestrol circulation 136. Young women are protected against (C) Their receptors are intracellular myocardial infaracation because of the (D) They require cyclic AMP as second messenger activity of 142. Cyclic AMP acts as the second messenger (A) Estrogen (B) Progesterone for (C) Growth hormone (D) Oxytocin (A) ADH (B) Glucagon 137. Hormone receptors possess all the (C) Calcitonin (D) All of these following properties except 143. Cyclic AMP acts as the second messenger (A) All of them are proteins for all of the following except (B) They possess a recognition domain (C) They bind hormones with a high degree of (A) Oxytocin (B) TSH specificity (C) ACTH (D) FSH (D) Number of receptors in a target cell is constant 216 MCQs IN BIOCHEMISTRY

144. Cyclic GMP acts as the second messenger 153. activity is present in for (A) α-Adrenergic receptors (A) Nerve growth factor (B) β-Adrenergic receptors (B) Atrial natriuretic factor (C) Cholinergic receptors (C) Epinephrine (D) Insulin receptors (D) Norepinephrine 154. is a 145. Some hormones produce their intra- (A) Monomer (B) Dimer cellular effects by activating (C) Trimer (D) Tetramer

(A) Phospholipae A1 (B) Phospholipase B 155. Tyrosine kinase activity is present in (C) Phospholipase C (D) All of these (A) Acetylcholine receptor 146. Inositol triphosphate is the second (B) PDGF receptor messenger for (C) ADH receptor (A) Gastrin (B) Cholecystokinin (D) All of these (C) Oxytocin (D) All of these 156. is activated by 147. G-proteins act as (A) Cyclic AMP (B) Cyclic GMP (C) Diacyl glycerol (D) Inositol triphosphate (A) Hormone carriers (B) Hormone receptors 157. Melatonin is synthesised in (C) Second messengers (A) Hypothalamus (D) Signal transducers (B) Posterior pituitary gland (C) Pineal gland 148. Signal transducer for glucagons is a (D) Melanocytes (A) Cyclic nucleotide 158. Melatonin is synthesised from (B) Phosphoinositide (A) Phenylalanine (B) Tyrosine (C) Stimulatory G-protein (C) Tryptophan (D) None of these (D) Inhibitory G-protein 159. Melanocyte stimulating hormone is 149. G-proteins are secreted by (A) Monomers (B) Dimers (A) Pineal gland (C) Trimers (D)Tetramers (B) Anterior lobe of pituitary gland 150. G-proteins have a nucleotide (C) Posterior lobe of pituitary gland for (D) Intermediate lobe of pituitary gland (A) ADP/ATP (B) GDP/GTP 160. MSH causes (C) CDP/CTP (D) UDP/UTP (A) Dispersal of melanin granules in melanocytes 151. The nucleotide binding site of G-proteins (B) Increase in melanin concentration in melano- cytes is present on their (C) Decerease in melanin concentration in melano- (A) α-Subunit (B) β-Subunit α- and β- cytes (C) γ-Subunit (D) δ-Subunit (D) Increase in number of melanocytes 152. Adenylate cyclase is activated by 161. Secretion of MSH is regulated by (A) GDP-bearing α-Subunit of G-protein (A) Feedback mechanism (B) GTP-bearing α-Subunit of G-protein (B) Melatonin (C) GDP-bearing γ-Subunit of G-protein (C) Hypothalamic hormones (D) GTP-bearing γ-Subunit of G-protein (D) ACTH HORMONE METABOLISM 217

162. A hormone synthesised in the hypothal- 171. Secretion of somatotrophin is promoted amus is by (A) Melatonin (A) Somatomedin C (B) Melanocyte stimulating hormone (B) Somatostatin (C) Vasopressin (C) Growth hormone releasing hormone (D) Prolactin (D) Hypoglycaemia 163. Posterior pituitary gland secretes 172. Human growth hormone has (A) Catecholamines (A) One polypeptide chain and one intra-chain disulphide bond (B) Oxytocin (B) One polypeptide chain and two intra-chain (C) Follicle stimulating hormone disulphide bond (D) Serotonin (C) Two polypeptide chains joined by one 164. A nonapeptide among the following is disulphide bond (D) Two polypeptide chains joined by two (A) Antidiuretic hormone disulphide bond (B) Insulin (C) ACTH 173. Number of amino acid residues in human growth hormone is (D) Thyrotropin releasing hormone (A) 51 (B) 84 165. Diabetes insipidus is caused by deficient (C) 191 (D) 198 secretion of 174. Number of amino acid residues in (A) Insulin (B) Glucagon prolactin is (C) Vasopressin (D) Oxytocin (A) 51 (B) 84 166. Peripheral vasoconstriction is caused by (C) 191 (D) 198 high concentrations of 175. Secretion of prolactin is regulated by (A) Antidiuretic hormone (A) Feedback inhibition (B) Melatonin (B) Prolactin releasing hormone (C) Glucagon (C) Prolactin release inhibiting hormone (D) Oxytocin (D) All of these 167. Somatotropin is secreted by 176. Precursor of ACTH is (A) Hypothalamus (B) Anterior pituitary (A) Cholesterol (B) Pregnenolone (C) Posterior pituitary (D) Thyroid gland (C) Corticotropin (D) Pro-opiomelanocortin 168. Secretion of Insulin-like Growth Factor-I 177. All of the following can be formed from is promoted by pro-opiomelanocortin except (A) Insulin (B) Glucagon (A) α-and β-MSH (B) β-and γ-Lipotropins (C) Growth hormone (D) Somatomedin C (C) α-and β-Endorphins(D) FSH 169. Growth hormone increases 178. All the following statements about pro- (A) Protein synthesis (B) Lipogenesis opiomelanocortin are true except (C) Glycogenolysis (D) All of these (A) It is made up of 285 amino acids (B) It is synthesised in pars intermedia and 170. Secretion of growth hormone is inhibited anterior lobe of pituitary gland by (C) It is the precursor of ACTH and melatonin (A) Somatomedin C (B) Somatostatin (D) It is the precursor of corticotropin like (C) Feedback inhibition(D) All of these intermediate lobe peptide and endorphins 218 MCQs IN BIOCHEMISTRY

179. All the following statements about ACTH 186. All the following statements about are true except thyrotropin releasing hormone are true (A) It is a tropic hormone except (B) Its target cells are located in adrenal cortex (A) It is secreted by hypothalamus (C) Its receptors are located in the cell membrane (B) It is a pentapeptide (D) Its second messenger is inositol triphosphate (C) It increases the secretion of TSH (D) Its secretion is inhibited by high level of T 180. Regulation of ACTH secretion occurs 3 and T in blood through 4 (A) Corticotropin releasing hormone (CRH) and 187. In males, luteinising hormone acts on corticotropin release inhibiting hormone (CRIH) (A) Leydig cells (B) Sertoli cells of hypothalamus (C) Prostate gland (D) All of these (B) Feedback inhibition by cortisol 188. All the following statements about FSH (C) CRH and feedback inhibition by cortisol are true except (D) CRIH and feedback inhibition by cortisol (A) It is a tropic hormone secreted by anterior 181. ACTH is a polypeptide made up of pituitary (A) 39 amino acids (B) 41 amino acids (B) Its secretion is increased by gonadotropin (C) 51 amino acids (D) 84 amino acids releasing hormone (C) It acts on Sertoli cells 182. CRH is a polypeptide made up of (D) It increases the synthesis of testosterone (A) 39 amino acids (B) 41 amino acids (C) 51 amino acids (D) 84 amino acids 189. In males, secretion of luteinising hormone is inhibited by 183. Hormonal activity of ACTH is completely lost on removal of (A) Gonadotropin releasing hormone (B) FSH (A) 5 C-terminal amino acids (C) High blood level of testosterone (B) 10 C-terminal amino acids (D) Inhibin (C) 15 C-terminal amino acids (D) None of these 190. Secretion of luteinising hormone is in- creased by 184. All the following statements about TSH are true except (A) GnRH (B) FSH (C) Testosterone (D) None of these (A) It is a glycoprotein (B) It is made up of α- and β-subunits 191. In structure and function, HCG resembles (C) Receptor recognition involves both the subunits (A) FSH (B) LH (D) Its subunit is identical with those of FSH and (C) GnRH (D) Progesterone LH 192. Acromegaly results from overproduction 185. All the following statements about TSH of are true except (A) ACTH during childhood (A) It is a tropic hormone (B) TSH during adult life (B) It acts on para-follicular cells of thyroid glands (C) Growth hormone during childhood (C) Its receptors are membrane-bound (D) Growth hormone during adult life (D) Its second messenger is cyclic AMP HORMONE METABOLISM 219

193. Acromegaly results in all the following 202. Thyroid hormones are present in blood except (A) In free form (A) Overgrowth of the bones of face, hands and (B) In association with thyroxine binding globulin feet (TBG) (B) Increased stature (C) In association with thyroxine binding pre- (C) Enlargements of viscera albumin (TBPA) (D) Impaired glucose tolerance (D) Mainly in association with TBG, partly in free 194. Overproduction of growth hormone form and sometimes in association with TBPA during childhood causes also (A) Acromegaly (B) Gigantism 203. When thyroxine binding globulin and (C) Cushing’s disease (D) Simmond’s disease thyroxine binding pre-albumin are sat- 195. Decreased secretion of growth hormone urated with thyroxine, the excess hor- during childhood causes mone is transported by (A) Simmond’s disease (B) Cushing’s disease (A) Albumin (B) Gamma globulins (C) Dwarfism (D) Cretinism (C) Transcortin (D) None of these

196. Stature is increased in 204. Receptors for thyroid hormones are present (A) Gigantism (B) Acromegaly (A) On the cell membrane (C) Simmond’s disease(D) Cushing’s disease (B) Across the cell membrane 197. An amino acid used for the synthesis of (C) Inside the cells thyroid hormone is (D) In association with G-proteins (A) Tyrosine (B) Tryptophan 205. Binding of thyroxine to its receptors (C) Histidine (D) Proline (A) Activates Adenylate cyclase 198. An enzyme required for the synthesis of thyroid hormones is (B) Activates (C) Activates a stimulatory G-protein (A) Iodinase (B) Deiodinase (C) Thyroperoxidase (D) Thyroxine synthetase (D) Increases transcription 199. Thyroperoxidase iodinates 206. The most powerful thyroid hormone is

(A) Free tyrosine in thyroid gland (A) Reverse T3 (B) DIT

(B) Tyrosine residues of thyroglobulin (C) T3 (D) T4 (C) Tyrosine residues of thyroxine binding globulin 207. The most abundant thyroid hormone in (D) Tyrosine residues of thyroxine binding blood is prealbumin (A) Free T3 (B) T3 bound to TBG 200. In thyroxine, tyrosine residues are iodi- (C) Free T (D) T bound to TBG nated at positions: 4 4 (A) 1 and 3 (B) 2 and 4 208. Secretion of thyroid hormones is regulated (C) 3 and 5 (D) 4 and 6 by (A) Hypothalamus 201. Thyroid gland takes up circulating iodine (B) Anterior pituitary (A) By simple diffusion (C) Feedback regulation (B) By facilitated diffusion (C) By active uptake (D) All of these (D) In exchange for chloride 220 MCQs IN BIOCHEMISTRY

209. Clinical features of hyperthyroidism 217. The second messenger for PTH is include (A) Cyclic AMP (B) Cyclic GMP (A) Goitre, heat intolerance, weight loss and (C) Diacylglycerol (D) Inositol triphosphate tachycardia 218. PTH causes all of the following except (B) Goitre, tremors, tachycardia and cold intolerance (A) Increased intestinal absorption of calcium (C) Exophthalmos, goiter, tachycardia and loss (B) Increased intestinal absorption of phosphate of appetite (C) Increased tubular reabsorption of calcium (D) Exophthalmos, goiter, tremors and obesity (D) Increased tubular reabsorption of phosphate

210. All the following may occur in hyperthy- 219. Secretion of PTH is regulated by roidism except (A) Hypothalamus (A) Goitre (B) Increased appetite (B) Anterior pituitary (C) Loss of weight (D) Low BMR (C) Feedback effect of plasma PTH 211. All the following may occur in myxoede- (D) Feedback effect of plasma calcium ma except 220. A high concentration of PTH in blood (A) Cold intolerance (B) Low BMR causes (C) Tachycardia (D) Dry and coarse skin (A) Increase in plasma calcium and inorganic 212. Mental retardation can occur in phosphorous (A) Cretinism (B) Decrease in plasma calcium and inorganic (B) Juvenile myxoedema phosphorous (C) Myxoedema (C) Increase in plasma calcium and decrease in (D) Juvenile thyrotoxicosis plasma inorganic phosphorous (D) Decrease in plasma calcium and increase in 213. Parathyroid hormone (PTH) is synthesised plasma inorganic phosphorous in (A) Chief cells of parathyroid glands 221. Tetany can occur (B) Oxyphil cells of parathyroid glands (A) In primary hyperparathyroidism (C) Para follicular cells of thyroid glands (B) In secondary hyperparathyroidism (D) Follicular cells of thyroid gland (C) In idiopathic hypoparathyroidism 214. The number of amino acid residues in PTH: (D) After accidental removal of parathyroid glands (A) 51 (B) 84 222. Crystallisation of insulin occurs in the (C) 90 (D) 115 presence of 215. Amino acid residues which are essential (A) Chromium (B) Copper for the biological activity of PTH are (C) Zinc (D) Calcium (A) N-terminal 34 amino acids 223. Daily secretion of insulin is about δ– (B) N-terminal 50 amino acids (A) 10–20 mg (B) 40–50 mg (C) C-terminal 34 amino acids (C) 10–20 units (D) 40–50 units (D) C-terminal 50 amino acids 224. Insulin receptors are decreased in number 216. Half-life of PTH is in (A) A few seconds (B) A few minutes (A) Obesity (B) Starvation (C) A few hours (D) A few days (C) Hyperinsulinism (D) Kwashiorkor HORMONE METABOLISM 221

225. Insulin binding sites are present on the 234. Insulin increases (A) α-subunits of insulin receptor (A) Protein synthesis (B) Fatty acid synthesis (B) β-subunits of insulin receptor (C) Glycogen synthesis (D) All of these (C) -subunits of insulin receptor γ 235. Insulin decreases the synthesis of (D) α-and β−subunits of insulin receptor (A) Hexokinase (B) Glucokinase 226. ααα-Subunits of insulin receptor are present (C) PEP carboxykinase (D) Glycogen synthetase (A) Outside the cell membrane 236. Diabetes mellitus can occur due to all of (B) In the cell membrane the following except (C) Across the cell membrane (A) Deficient insulin secretion (D) In the cytosol (B) Tumour of β−cells 227. βββ-Subunits of insulin receptor are present (C) Decrease in number of insulin receptors (A) Outside the cell membrane (D) Formation of insulin antibodies (B) In the cell membrane 237. Hypoglycaemic coma can occur (C) Across the cell membrane (A) In untreated diabetes mellitus (D) In the cytosol (B) In starvation 228. In the insulin receptor, tyrosine kinase (C) After overdose of oral hypoglycaemic drugs domain is present in (D) After overdose of insulin (A) α-Subunits (B) β-Subunits 238. Second messenger for glucagons is (C) γ-Subunits (D) δ-Subunits (A) Cyclic AMP (B) Diacylglycerol 229. Binding of insulin to its receptor activates (C) Cyclic GMP (D) Inositol triphosphate (A) Adenylate cyclase (B) Guanylate cyclase 239. Number of amino acid residues in (C) Phospholipase C (D) Tyrosine kinase glucagons is 230. Insulin receptor is made up of (A) 29 (B) 34 (A) One α-and one β-subunit (C) 51 (D) 84 (B) Two -and two -subunit α β 240. Glucagon secretion increases (C) Two, α two β-and two γ-subunit (A) After a carbohydrate-rich meal (D) One α, one β-one γ-and one δ-subunit (B) After a fat-rich meal 231. Insulin is required for the active uptake (C) When blood glucose is high of glucose by most of the cells except (D) When blood glucose is low (A) Muscle cells (B) Renal tubular cells 241. The maineffecting of glucagons is to (C) Adipocytes (D) Liver cells increase 232. Insulin decreases (A) Glycolysis in muscles (A) Glycogenesis (B) Glycogenolysis in muscles (B) Glyolysis (C) Glycogenolysis in liver (C) Gluconeogenesis (D) Glycogenesis in liver (D) Tubular reabsorption of glucose 242. Tyrosine is required for the synthesis of 233. Insulin increases all of the following except (A) Glycogenesis (B) Gluconeogenesis (A) Melatonin (B) Epinephrine (C) Lipolysis (D) Blood glucose (C) Norepinephrine (D) Thyroxine 222 MCQs IN BIOCHEMISTRY

243. Dopamine is synthesised from 251. Binding of catecholamines to ααα222−−− adrenergic receptors (A) Dihydroxyphenylalanine (B) Epinephrine (A) Increases the intracellular concentration of cAMP (C) Norepinephrine (B) Increases the intracellular concentration of (D) Metanephrine cGMP 244. Blood brain barrier can be crossed by (C) Decreases the intracellular concentration of cAMP (A) Epinephrine (B) Dopamine (D) Decreases the intracellular concentration of (C) Dopa (D) All of these cGMP 245. Epinephrine is synthesised in 252. Phosphoinositide cascade is activated on (A) Chromaffin cells of adrenal medulla binding of catecholamines to

(B) Sympathetic ganglia (A) α1-Adrenergic receptors

(C) Brain (B) α2-Adrenergic receptors (D) All of these (C) β1-Adrenergic receptors (D) β2-Adrenergic receptors 246. Immediate precursor of epinephrine is 253. Epinephrine decreases (A) Metanephrine (B) Norepinephrine (A) Glycogenesis (B) Glycogenolysis (C) Dopa (D) Dopamine (C) Gluconeogenesis (D) Lipolysis 247. The chief metabolite of catecholamines is 254. Epinephrine increases the concentration (A) Metanephrine of free fatty acids in plasma by increasing (B) Normetanephrine (A) Extramitochondrial fatty acid synthesis (C) 3, 4-Dihydroxymandelic acid (B) Mitochondrial fatty acid chain elongation (D) Vanillylmandelic acid (C) Microsomal fatty acid chain elongation (D) Lipolysis in adipose tissue 248. An enzyme involved in catabolism of catecholamines is 255. Epinephrine increases all of the following (A) Dopa decarboxylase except (B) Aromatic amino acid decarboxylase (A) Glycogenolysis in muscles (C) Monoamine oxidase (B) Lipolysis in adipose tissue (C) Gluconeogenesis in muscles (D) Catechol oxidas (D) Glucagon secretion 249. Norepinephrine binds mainly to 256. Secretion of catecholamines is increased (A) α-Adrenergic receptors in (B) β-Adrenergic receptrors (A) Cushing’s syndrome (C) Muscarinic receptors (B) Addison’s disease (D) Nicotinic receptors (C) Phaeochromocytoma 250. Astimulatory G-protein transduces the (D) Simmond’s disease signals from 257. Zona glomerulosa of adrenal cortex syn- thesises (A) α1-and β1-adrenergic receptors (A) Glucocorticoids (B) α2-and β2-adrenergic receptors (B) Mineralocorticoids (C) α1-and α2-adrenergic receptors (C) Androgens (D) β1-and β2-adrenergic receptors (D) Estrogen and progesterone HORMONE METABOLISM 223

258. Cortisol is a 267. The second messenger for glucocorticoids (A) Glucocorticoid (B) Mineralocorticoid is (C) Androgen (D) Estrogen (A) Cyclic AMP 259. The major mineralcorticoid is (B) Cyclic GMP (A) Hydrocortisone (B) Aldosterone (C) Inositol triphosphate (C) Aldactone A (D) Androstenedione (D) No second messenger is required 260. Steroid hormones are synthesised in all 268. Glucocorticoids increase all of the follow- of the following except ing except (A) Testes (B) Ovaries (A) Gluconeogenesis (C) Adrenal medulla (D) Adrenal cortex (B) Lipolysis in extremities 261. Steroid hormones are synthesised from (C) Synthesis of elcosanoida (A) Cholesterol (D) Hepatic glycogenesis (B) 7-Dehydrocholesterol 269. Glucocorticoids increase the synthesis of (C) Calcitriol all of the following except (D) 7-Hydroxycholesterol (A) Glucokinase 262. A common intermediate in the synthesis (B) Glucose-6-phosphatase of all the steroid hormones is (C) Fructose-1, 6-biphosphatase (A) Pregnenolone (D) Pyruvate carboxylase (B) 17-Hydroxypregnenolone (C) Corticosterone 270. Secretion of glucocorticoida is regulated (D) Progesterone by all the following except (A) Hypothalamus 263. A common intermediate in the synthesis of cortisol and aldosterone is (B) Anterior pituitary (A) Progesterone (B) Testosterone (C) Feedback control by blood glucose (C) Estradiol (D) None of these (D) Feedback control by glucocorticoids 264. A common intermediate in the synthesis 271. Excessive secretion of glucocorticoids rais- of estrogens is es blood glucose by (A) Cortisol (A) Decreasing glycogenesis (B) Andostenedione (B) Increasing glycogenolysis (C) Corticosterone (C) Increasing gluconeogenesis (D) 11-Deoxycorticosterone (D) Inhibiting HMP shunt 265. Glucocorticoids are transported in blood 272. Mineralcorticoids regulate the metabo- (A) In association with transcortin chiefly lism of all of the following except (B) In association with albumin to some extent (A) Sodium (B) Potassium (C) In free form partly (C) Calcium (D) Chloride (D) All of these 273. Mineralocorticoids increase the tubular 266. All the following statements about trans- cortin are true except reabsorption of (A) It is synthesised in liver (A) Sodium and calcium (B) It transports glucocorticoids (B) Sodium and potassium (C) It transports aldosterone (C) Sodium and chloride (D) It transports progesterone (D) Potassium and chloride 224 MCQs IN BIOCHEMISTRY

274. Mineralocorticoids increase the tubular 283. Secretion of androgens is increased by secretion of (A) LH (B) FSH (A) Sodium (B) Potassium (C) ACTH (D) Growth hormone (C) Chloride (D) Bicarbonate 284. During late pregnancy, the major source 275. Secretion of mineralcorticoids is increased of progesterone is by (A) Adrenal cortex (B) Placenta (A) ACTH (B) Angiotensin (C) Corpus luteum (D) Graafian follicles (C) Hypokalaemia (D) Hypernatraemia 285. Progesterone is transported in blood by 276. In Addison’s disease, there is excessive retention of (A) Transcortin (B) Sex hormone binding globulin (A) Potassium (B) Sodium (C) Albumin (C) Chloride (D) Water (D) Testosterone estrogen binding globulin 277. In adrenogenital syndrome due to total absence of 21-hydroxylase in adrenal 286. The major metabolite of progesterone is cortex, there is (A) Pregnenolone (B) Pregnanediol (A) Deficient secretion of glucocorticoids (C) Estradiol (D) Norethindrone (B) Deficient secretion of mineralcorticoids 287. Secretion of progesterone (C) Excessive secretion of androgens (A) Is more in first half of menstrual cycle than in (D) All of these second half 278. Spironolactone is an antagonist of (B) Is more in second half of menstrual cycle than (A) Cortisol (B) Hydrocortisone in first half (C) Aldosterone (D) Testosterone (C) Remains constant during menstrual cycle (D) Decreases during pregnancy 279. Androgens are synthesised in (A) Leydig cells in testes 288. Women become susceptible to osteoporo- sis after menopause due to decreased (B) Sertoli cells in testes (C) Seminiferous tubules (A) Secretion of Parathormone (D) Prostate gland (B) Conversion of vitamin D into calcitriol (C) Secretion of estrogen 280. Testosterone is transported in blood by (D) Secretion of progesterone (A) Transcortin (B) Testosterone binding globulin 289. A hormone used for detection of pregnan- cy is (C) Testosterone estrogen binding globulin (D) Albumin (A) Estrogen (B) Progesterone 281. The metabolites of androgens are (C) Oxytocin (A) 17-Hydroxysteroids (D) Chorionic gonadotropin (B) 17-Ketosteroids 290. Placenta secretes all of the following (C) 11-Hydroxysteroids except (D) 11-Ketosteroids (A) FSH 282. An androgen which is more powerful (B) Progesterone than testosterone is (C) Estrogen (A) Androstenedione (B) Dihydrotestosterone (D) Chorionic gonadotropin (C) Androsterone (D) Epiandrosterone HORMONE METABOLISM 225

291. Gastrin is a polypeptide made up of 299. Tyrosine hydroxylase is inhibited by (A) Five amino acids (A) Catecholamines (B) α−Methyldopa (B) Twelve amino acids (C) Phenylalanine (D) Vanillyl mandelic acid (C) Seventeen amino acids 300. Urinary excretion of vanillyl madelic acid (D) Twenty amino acids is increased in 292. Biological activity of gastrin is present in (A) Phaeochromocytoma the (B) Cushing’s syndrome (A) Four N-terminal amino acids (C) Carcinoid syndrome (B) Four C-terminal amino acids (D) Aldosteronism (C) Five N-terminal amino acids (D) Five C-terminal amino acids 301. Iodide uptake by thyroid gland is de- creased by 293. All the following statements about βββ- (A) Thicyanate (B) Thiouracil endorphin are true except µ : (C) Thiourea (D) Methimazole (A) It is a polypeptide (B) Its precursor is pro-opio-melanocortin 302. Binding of growth hormone to its receptor results in phosphorylation of (C) Its receptors are represent in brain (D) Its action is blocked by morphine (A) JAK-2 (B) Growth hormone receptor 294. All the following statements about epidermal growth factor are true except (C) STATs (D) All of these (A) It is a protein (B) It possess quaternary structure 303. Binding of growth hormone to its (C) Its receptor is made up of a single polypep- receptor results in increased transcription tide chain of (D) Its receptor possesses tyrosine kinase domain (A) c-fos gene (B) c-myc gene 295. Met-enkephalin is a (C) p-53 gene (D) None of these (A) Tripeptide (B) Pentapeptide 304. Activation of IRS-1, PI-3 kinase and GRB- (C) Octapeptide (D) Decapeptide 2 is brought about by 296. Vasoconstrictor effect of ADH is mediated (A) Glucagon (B) Insulin by (C) Prolactin (D) IGF-2 (A) cAMP (B) cGMP 305. The protein IRS-1 is phosphorylated by (C) Protein kinase C (D) Angiotensin II (A) 297. The rate limiting step in catecholamine (B) Protein kinase C synthesis is catalysed by (C) Tyrosine kinase activity of insulin receptor (A) Phenylalanine hydroxylase (D) Tyrosine kinase activity of IGF-1 receptor (B) Tyrosine hydroxylase 306. Phosphorylated IRS-1 activates GRB-2 (C) Dopa decarboxylase which is (D) Phenylethanolamine N-methyl transferase (A) G-protein receptor binding protein-2 298. Dopa decarboxylase is inhibited by (B) Growth factor receptor binding protein-2 (A) Epinephrine (B) Norepinephrine (C) Growth hormone receptor binding protein-2 (C) α−Methyldopa (D) None of these (D) Glucocorticoid receptor binding protein-2 226 MCQs IN BIOCHEMISTRY

307. STAT proteins are 315. Normal range of total thyroxine in serum (A) Thermostat proteins of brain is (B) Glucostat proteins of hepatocyte cell (A) 0.8–2.4 ng/dl (B) 0.8–2.4 µg/dl membrane (C) 5–12 ng/dl (D) 5–12 µg/dl (C) Short term activators of translation (D) Signal transduction and activators of 316. Normal range of total tri-iodothyronine transcription in serum is (A) 0.1–0.2 ng/dl (B) 0.1–0.2 µg/dl 308. Activated phospholipase C acts on (C) 0.8–2.4 ng/dl (D) 0.8–2.4 µg/dl (A) Phosphatidyl inositol-4, 5-biphosphate

(B) Inositol-1, 4, 5-triphosphate 317. Administration of TSH increases serum T3 and T in (C) Protein kinase C 4 (D) Pl-3 kinase (A) Hyperthyroidism of pituitary origin (B) Hyperthyroidism of thyroid origin 309. Phospholipase C is activated by (C) Hypothyroidism of pituitary origin (A) G proteins (B) G proteins s i (D) Hypothyroidism of thyroid origin (C) Gq proteins (D) G12 proteins 318. High level of T3 and T4 and low TSH in 310. Proteoglycans are made up of proteins serum indicates and (A) Hyperthyroidism of pituitary origin (A) Glucosamine (B) Mannosamine (B) Hypothyroidism of pituitary origin (C) Sialic acid (D) Mucopolysaccharides (C) Hyperthyroidism of thyroid origin 311 Sweat chlorides are increased in (D) Hypothyroidism of thyroid origin (A) Cystic fibrosis (B) Pancreatic cancer 319. BMR is increased in (C) Acute pancreatitis (D) None of these (A) Endemic goitre (B) Thyrotoxicosis 312. All the following statements about cystic (C) Myxoedema (D) Cretinism fibrosis are correct except 320. Which one of the following statements (A) It is inherited as an autosomal recessive correctly describes eukaryotic DNA? disease (A) If uses DNA polymerase with nuclease (B) It affects a number of exocrine glands activities (C) It causes increased sweating (B) It is replicated bidirectionally at many points (D) Sweat chlorides are above 60 mEq/L in this (C) It contains no repetitive DNA disease (D) It is nonlinear 313. Radioactive iodine uptake by thyroid 321. Which one of the following causes frame gland 24 hours of a test dose is shift mutation? (A) 1.5–15% of the test done (A) Transition (B) 15–20% of the test done (B) Transversion (C) 20–40% of the test done (C) Deletion (D) 50–70% of the test done (D) Substitution of purine to pyrimidine 314. Radioactive iodine uptake by thyroid 322. The second messenger for many hor- gland is increased in mones is (A) Endemic goitre (B) Hyperthyroidism (A) ATP (B) cyclic AMP (C) Myxoedema (D) Creatinism (C) cGMP (D) UTP HORMONE METABOLISM 227

323. The most potent hormone concerned with 331. In hyperparathyroidism there is the retention of sodium in the body is (A) Hypocalcemia (B) Hypophophatemia (A) Cortisone (B) Aldosterone (C) Hypokalemia (D) Hyperkalemia (C) Corticosterone (D) Cortisol 332. Insulin resistance is encountered in 324. Aspirin blocks the synthesis of (A) Addison’s disease (B) Hypothyroidism (A) Prostaglandins only (C) Hypopituctarism (D) Acromegaly (B) Prostacyclins only 333. Richest source of prostaglandins in a (C) Thromboxanes only human male is (D) All of these (A) Blood (B) Urine 325. Retention of sodium in the body leads to (C) Semen (D) C.S.F. a retention of 334. One of the following is not used as a (A) Potassium second messenger by hormones: (B) Water (A) mRNA (C) Potassium and water (B) cAMP (D) Neither potassium nor water (C) Calcium ions 326. cAMP is so called because it is formed (D) Myoinisotol 1, 4, 5 triphosphate during 335. This pancreatic hormone increases the (A) TCA cycle blood-sugar level: (B) Urea cycle (A) Insulin (C) Rhodopsin cycle (B) Glucagon (D) It has a cyclic structure (C) Pancreozymin 327. Protein bound iodine is ______bound (D) Pancreatic polypeptide to protein. 336. Which one of the following statements is (A) Iodine (B) Thyroid hormones fully correct? (C) Thyroxine (D) Tri iodo thyronine (A) Hormones are needed in the diet 328. In hypophysectonized animals, fasting (B) Hormones can be elaborated only by produces endocrine glands (C) All the hormones enter the cells and perform (A) Severe hyperglycemia their function (B) Hypoglycemia (D) Hormones are substance synthesized in the (C) No change in blood sugar body in small quantities and control and (D) Mild hyper glycemia regulate metabolic events 329. Calcitomica is antagonist to 337. T3 is (A) Serotonin (A) Thyroxine (B) Thyroxine (B) Triodo thyronine (C) Tri iodo thyronine (C) Triodo tyrosine (D) Para thyroid hormone (D) Reverse tri iodo thyronine 330. There is polyuria without glycosuria in 338. Whcih of the following hormone is a this disorder peptide of less than ten amino acids? (A) Diabetes insipidus (B) Diabetes millitus (A) Insulin (B) Growth hormone (C) Bronze diabetes (D) Juvenile diabetes (C) Oxytocin (D) Parathyroid hormone 228 MCQs IN BIOCHEMISTRY

339. Tyrosine of thyroglobulin is acted upon 347. The blood sugar raising action of the by ______to give mono and diiodo hormone of suprarenal cortex is due to . (A) Glyconeogenesis (A) Potassium Iodide (B) Glycogenolysis (B) Iodine (C) Glucagon like activity (C) Iodide I (D) due to inhibition of glomerular filtration of (D) Higher valency state of iodine (I+) glucose 348. Hyper insulinism can cause coma since 340. Whcih of the following hormone does not activate adenylate cyclase? (A) The chief nutrient for the brain is glucose (A) Epinephrine (B) The chief nutrient for the heart is glucose (C) The glucostatic role of the liver is damaged (B) Glucagon (D) The kidneys are damaged (C) Parathyroid hormone (D) Insulin 349. Which of the following property of prostaglandins has been utilized by 341. Pheochromacytoma is a tumor of chinicians in hospital for (A) adrenal medulla (A) Inducing fever (B) bone (B) Causing inflammation (C) head of Pancreas (C) Effecting smooth muscle contraction (D) pituitary (D) Disaggregation of spermatozoa 342. Which one of the following statements is 350. A major structural difference between incorrect? estrogens and androgens is the fact that

(A) Insulin increases glucose phosphorylation (A) The androgens are usually C21 steroids (B) Insulin increases glycolysis (B) The estrogens are usually digitonin - precipitable (C) Insulin augments HMP shunt (C) The androgens have an aromatic ring (D) Insulin promotes gluconeogenesis (D) The estrogens have an aromatic ring 343. Which of one ring in the structure of the 351. Alloxan can experimentally induce following is aromatic? diabetes mellitus due to (A) Androgens (B) Estrogens (A) Stimulation of α cells of the islets of langerhans (C) Cholesterol (D) Bile acids (B) Necrosis of the β cells of the islets 344. Which of one of the following is not GUT hormone? (C) Potentiation of insulinase activity (A) Motiline (B) Secretion (D) Epinephrine like action (C) Gastrin (D) Calcitonin 352. Which of the following alleviates asthma?

345. Which of the following hormones are (A) PGE1 only (B) PGE1 and PGE2 synthesized as prehormones (C) PGF2 (D) PGA (A) Vasopressin and oxytocin 353. Thyroxine is derived from (B) Growth hormone and insulin (A) Tyrosine (B) Tyranine (C) Insulin and parathyroid hormone (C) Taurine (D) Tryptaine (D) Insulin and Glucagon 354. Adrneal cortical response is poor in 346. This hormone has disulphide group: (A) Glucagon (B) Insulin (A) Kwashiorkor (B) Marasmus (C) Fatty liver (D) Atherosclerosis (C) T4 (D) Epinephrine HORMONE METABOLISM 229

355. Protein bound iodine in blood is present 364. Which of one of the following is released to the extent of ______/ dL by hypothalamus? (A) 3–8 mg (B) 4–8 mg (A) Somatostatin (C) 3–8 gm (D) 4–8 gm (B) Somatotropic hormone 356. Prostaglandins are (C) Somato medin C (D) Luteinising hormone (A) C2 unsaturated acids

(B) C27 saturated alcohols 365. Which one of the following is not liberated

(C) C20 saturated acids by the adenohypophysis? (D) C27 saturated alcohols (A) Growth hormone (B) TSH 357. Which of tne of the following scientists (C) ACTH (D) Gonadotropin has not worked in the field of pros- 366. Which of the following hormone is not taglandins? under the control of ACTH? (A) Voneuler (B) Sultan Karim (A) Aldosterone (B) Cortisol (C) Andre robet (D) Kendal (C) Corticosterone (D) Deoxycorticosterone 358. The suffix number in the names of prostaglandins gives the number of 367. Which of the following organ prefers fructose to glucose (A) OH groups (B) Double bonds (C) Acid groups (D) Ketoacids (A) Liver (B)Testes (C) Pancreas (D) Heart 359. One of the important functions of prostacyclins is 368. Total synthesis of creatine can be done by (A) Inhibition of platelet aggregation (A) Liver (B) Kidneys (B) Contraction of uterus (C) Pancreas (D) Heart (C) Decrease of gastric secretion 369. Thyrotropin releasing hormone is a (D) Relieving osthma (A) Dipeptide (B) Tripeptide 360. Vasopressin is also known as (C) Octapeptide (D) Decapeptide (A) Antidiabetogenic hormone 370. Hypthalamo ______gonadal oxis, fill (B) Antidiuretic hormone up the blank with the suitable word. (C) Somatotropic hormone (A) Adrenal (B) Thyroid (D) Pitoxin (C) Hypophyseal (D) Pancreatic 361. Which of the following is used for inducing 371. The sequence of amino acids in human labour? growth hormone and the synthesis were (A) Prostaglandins (B) Prostacyclins done by (C) Vasopressin (D) Thromboxanes (A) Sanger (B) Krebs 362. Which of the following does not have (C) Chah Holi (D) Molisch disulphide bond? 372. Proopiomelanocortin is the precussor of (A) Oxytocin (B) Vasopressin (A) ACTH (B) β-tropin (C) Insulin (D) Glucagon (C) Endorphins (D) All of these 363. Which is incorrect ? Epinephrin promotes 373. Adrenalin is synthesized from the glycogenolysis in (A) Adenine (B) Adenosine (A) Muscle (B) Liver (C) Tyrosine (D) Tryptophan (C) Heart (D) None of these 230 MCQs IN BIOCHEMISTRY

374. Corticotropin releasing hormone controls 382. Aldosteronism will present the chemical the direct release of pathology of (A) Pro-opiomelanocortin (A) Addison’s (B) Cushing’s (B) α MSH (C) Grave’s (D) Hartnup’s (C) β MSH 383. One of the following does not bind T and (D) Endorphins 3 T4: 375. The immediate parent of α, β and γ en- α, β α, β γ (A) Albumin (B) TBG dorphins is (C) TBPA (D) Haptoglobin (A) Pro-opiomelanocortin (B) β-lipotropin 384. Epinephrine causes in muscle: (C) ATCH (A) Gluconeogenesis (B) Glycogenesis (D) Lipoprotein (C) Glycolysis (D) Glycogenolysis 376. Prolactin release inhibiting hormone is 385. Reverse T3 is believed to be (A) A synthetic compound given counter the effects (A) Serotonin (B) Norepinephrine of T3 (C) Dopanine (D) Acetyl choline (B) Formed from T4 but has no hormone function

377. Whcih one of the following is not a (C) Formed by isomerisation of T3 symptom of cushing’s disease? (D) Formed from T4 and has hormone function (A) Hyperglycemia (B) Hypernatremia 386. This pancreatic hormone promotes hypo- (C) Hirsutism (D) Hyperkalemia genesis: 378. Insulin increases the permeability of (A) Insulin (B) Glucagon glucose across the plasma membrane of (C) Stomato station (D) Pancreozymine muscle cells by (A) Acting on adenylate cycle 387. It is unique that the following single antidiabetogenic hormone effectively (B) By loosening the integrity of the membrane counter acts the several diabetogenic 2+ (C) Through Ca ions hormones: (D) By membrane cruting the hexose carries of (A) Glucagon (B) Glucocorticoids intracellular organelles and making them fuse (C) Insulin (D) Growth hormone with the plasma membrane 388. Which of the following statements is 379. Somatostatin is produced by correct? (A) Hypothalamus (A) Thyroxine inhibits utilization of glucose (B) Pancreas (B) Insulin increases utilization of glucose (C) Hypothalamus and pancreas (C) Glucagon promotes muscle glycogenolysis (D) Hypothalamus and Adrenals (D) Insulin inhibits lipogenesis from carbohydrates

380. Insulin like growth hormones are pro- 389. Steroid hormones are synthesized from duced by (A) Adenine (B) Protein (A) Hypophysis (B) Liver (C) Vitamin (D) Cholesterol (C) Pancreas (D) Thyroid 390. Hormones act only on specific organs or tissues. These are called 381. In pheochromocytoma, urine will have (A) Active sites (B) Reaction centre (A) FILGU (B) VMA (C) Target organ/Tissue(D) Physiological site (C) 5 HIAA (D) Lysine and Arginine HORMONE METABOLISM 231

391. ______hormone is a single chain 398. Insulin regulates fatty acid synthesis by polypeptide having 32 amino acids with (A) Dephosphorylating of acetyl CoA carboxy- molecular weight of 3,600. lase (A) Testosteron (B) Thyroxine (B) Activating phosphorylase (C) Calcitonine (D) Vasopressin (C) Inhibiting malonyl CoA formation (D) Controlling carnitine-Acyl CoA transferase 392. Which of the following is noted in activity cushing’s syndrome, a tumor associated 399. Hormonal stimulation of the formation of disease of the adrenal cortex? the second messenger inositol 1,4,5 (A) Decreased production of epinephrine triphosphate (IP3) quickly leads to the (B) Excessive production of epinephrine release of which other intracellular messenger? (C) Excessive production of vasopressin (D) Excessive production of cortisol (A) cAMP (B) Prostaglandin (C) Calcinon (D) Leukotriene 393. A cup of strong coffee would be expected to 400. Hormone receptors that stimulate cAMP production (A) Interfere with synthesis of prostaglandins (A) are part of a complex of two proteins that (B) Decrease the effects of Glucagon transform the external signal into internal (C) Enhance the effects of epinephrine cAMP production (D) Provide the vitamin nicotinic acid (B) are proteins distinct and separate from those that catalyze the production of cAMP 394. Increased reabsorption of water from the (C) cause release of the catalytic subunit upon kidney is the major consequence of which binding of the hormone of the following hormones? (D) are not very specific and bind a number of (A) Cortisol (B) Insulin different hormones (C) Vasopressin (D) Aldosterone 401. All the following hormones use cAMP as 395. Lack of Glucocorticoids and mineral a second messenger except corticoids might be consequence of which (A) Estrogen (B) FSH of the following defects in the adrenal (C) Luteinizing (D) Glucagon cortex? 402. All the following hormones promote (A) Androstenadione deficiency hyperglycemia except (B) Estrone deficiency (A) Epinephrine (B) Norepinephrine (C) 17 α-OH progesterone deficiency (C) Insulin (D) Glucagon (D) C- α-Hydroxylase deficiency 403. Glucagon activates the enzyme adenyl- 396. ADP ribosylation is the mode of action of cyclase which causes the increase of blood (A) Cholera toxin sugar level. Hence this hormone is called (B) Acetyl choline (A) Hypoglycemic factor (C) Muscerinic receptors (B) Hyper glycemic factor (C) Antidiauritic factor (D) Cyclic AMP (D) Thyrotropin-releasing factor 397. Which one of the following hormones is 404. TSH hormone biochemically is a derived most completely from tyrosine? (A) Protein (B) Fat (A) Glucagon (B) Thyroxine (C) Glycoprotein (D) Carbohydrate (C) Insulin (D) Prostaglandins 232 MCQs IN BIOCHEMISTRY

405. The secondary sexual characters in females 409. Which of the following hormones is not is effected by involved in carbohydrate metabolism? (A) Estrogens (B) Gluco corticoids (A) ACTH (B) Glucagon (C) MIS (D) None of these (C) Vasopressin (D) Growth hormone

406. A hypochromic microcytic anaemia which 410. In the process of transcription, the flow of genetic information is from increases Fe, store in the bone marrow may be (A) DNA to DNA (B) DNA to protein (C) RNA to protein (D) DNA to RNA (A) Folic acid responsive 411. Anticodon region is an important part of (B) Vitamin B12 responsive (C) Pyridoxine responsive the structure of (D) Vitamin C responsive (A) r-RNA (B) t-RNA (C) m-RNA (D) z-DNA 407. Gastric Secretion is regulated by the hormone: 412. Thyroid function is determined by the use of isotopes: (A) Glucagon (B) Gastrin (A) Na24 (B) K42 (C) Epinephrin (D) ACTH (C) Ca45 (D) I131 408. An essential agent for converting glucose 413. Pernicious anaemia is diagnosed by the to glycogen in liver is radio active substance: (A) Latic acid (B) GTP (A) Cl36 (B) P32 (C) UTP (D) Pyruvic acid (C) CO60 (D) Fe59 HORMONE METABOLISM 233

ANSWERS 1. C 2. B 3. A 4. A 5. A 6. C 7. A 8. B 9. B 10. D 11. B 12. B 13. A 14. A 15. B 16. A 17. B 18. C 19. A 20. C 21. A 22. C 23. A 24. B 25. C 26. A 27. C 28. A 29. C 30. A 31. C 32. C 33. C 34. A 35. A 36. A 37. A 38. C 39. B 40. B 41. A 42. A 43. A 44. C 45. B 46. C 47. A 48. A 49. A 50. B 51. C 52. B 53. B 54. C 55. C 56. D 57. C 58. C 59. B 60. B 61. A 62. B 63. D 64. C 65. A 66. A 67. D 68. B 69. A 70. D 71. C 72. D 73. B 74. B 75. A 76. C 77. A 78. D 79. C 80. C 81. A 82. D 83. B 84. A 85. A 86. C 87. A 88. B 89. A 90. D 91. C 92. B 93. D 94. D 95. A 96. B 97. B 98. A 99. A 100. A 101. A 102. B 103. D 104. C 105. B 106. B 107. A 108. A 109. B 110. C 111. C 112. B 113. A 114. C 115. C 116. C 117. C 118. B 119. C 120. A 121. D 122. C 123. B 124. A 125. B 126. A 127. A 128. B 129. A 130. D 131. B 132. D 133. D 134.C 135. A 136. A 137. D 138. D 139. D 140. A 141. D 142. D 143. A 144. B 145. C 146. D 147. D 148. C 149. C 150. B 151. A 152. B 153. D 154. D 155. B 156. C 157. C 158. C 159. D 160. B 161. C 162. C 163. B 164. A 165. C 166. A 167. B 168. C 169. A 170. B 171. C 172. B 173. C 174. D 175. C 176. D 177. D 178. C 179. D 180. C 181. A 182. B 183. D 184. D 185. B 186. B 187. A 188. D 189. C 190. A 191. B 192. D 193. B 194. B 195. C 196. A 197. A 198. C 199. B 200. C 201. C 202. D 203. A 204. C 205. D 206. C 207. D 208. D 209. A 210. D 211. C 212. A 213. A 214. B 215. A 216. B 217. A 218. D 219. D 220. C 221. D 222. C 223. D 224. A 225. A 226. A 227. C 228. B 229. D 230. B 231. D 232. C 233. A 234. D 235. C 236. B 237. D 238. A 239. A 240. D 241. C 242. A 243. A 244. C 245. D 246. B 234 MCQs IN BIOCHEMISTRY

247. D 248. C 249. A 250. D 251. C 252. A 253. A 254. D 255. C 256. C 257. A 258. B 259. C 260. A 261. A 262. A 263. A 264. B 265. D 266. C 267. D 268. C 269. A 270. C 271. C 272. C 273. C 274. B 275. B 276. A 277. D 278. C 279. A 280. C 281. B 282. B 283. A 284. B 285. A 286. B 287. B 288. C 289. D 290. A 291. C 292. B 293. D 294. B 295. B 296. C 297. B 298. C 299. A 300. A 301. A 302. D 303. A 304. B 305. B 306. B 307. D 308. A 309. C 310. D 311. A 312. C 313. C 314. B 315. D 316. B 317. C 318. C 319. B 320. C 321. C 322. B 323. B 324. D 325. B 326. D 327. B 328. B 329. D 330. A 331. B 332. D 333. C 334. A 335. B 336. D 337. B 338. C 339. D 340. D 341. A 342. D 343. B 344. D 345. C 346. B 347. A 348. A 349. C 350. D 351. B 352. B 353. A 354. A 355. A 356. A 357. D 358. B 359. A 360. A 361. A 362. D 363. C 364. A 365. D 366. A 367. B 368. C 369. B 370. C 371. C 372. D 373. C 374. A 375. B 376. C 377. D 378. D 379. C 380. B 381. B 382. B 383. D 384. D 385. B 386. A 387. C 388. B 389. D 390. C 391. C 392. D 393. C 394. C 395. D 396. A 397. B 398. A 399. C 400. B 401. A 402. C 403. B 404. C 405. A 406. D 407. B 408. C 409. C 410. D 411. B 412. D 413. C NUCLEIC ACIDS 235

CHAPTER 9

NNNUCLEICUCLEICUCLEIC AAACIDSCIDSCIDS

1. A nucleoside consists of 7. The chemical name of guanine is (A) Nitrogenous base (A) 2,4-Dioxy-5-methylpyrimidine (B) Purine or pyrimidine base + sugar (B) 2-Amino-6-oxypurine (C) Purine or pyrimidine base + phosphorous (C) 2-Oxy-4-aminopyrimidine (D) Purine + pyrimidine base + sugar + (D) 2, 4-Dioxypyrimidine phosphorous 8. Nucleotides and nucleic acids concentration 2. A nucleotide consists of are often also expressed in terms of (A) A nitrogenous base like choline (A) ng (B) mg (B) Purine + pyrimidine base + sugar + (C) meq (D) OD at 260 nm phosphorous (C) Purine or pyrimidine base + sugar 9. The pyrimidine nucleotide acting as the (D) Purine or pyrimidine base + phosphorous high energy intermediate is 3. A purine nucleotide is (A) ATP (B) UTP (A) AMP (B) UMP (C) UDPG (D) CMP (C) CMP (D)TMP 10. The carbon of the pentose in ester linkage 4. A pyrimidine nucleotide is with the phosphate in a nucleotide struc- ture is (A) GMP (B) AMP (A) C (B) C (C) CMP (D)IMP 1 3 (C) C4 (D) C5 5. Adenine is 11. Uracil and ribose form (A) 6-Amino purine (B) 2-Amino-6-oxypurine (A) Uridine (B) Cytidine (C) 2-Oxy-4-aminopyrimidine (C) Guanosine (D) Adenosine (D) 2, 4-Dioxypyrimidine 12. The most abundant free nucleotide in 6. 2, 4-Dioxypyrimidine is mammalian cells is (A) Thymine (B) Cystosine (A) ATP (B) NAD (C) Uracil (D) Guanine (C) GTP (D) FAD 236 MCQs IN BIOCHEMISTRY

13. The mean intracellular concentration of 21. The nitrogenous base present in the RNA ATP in mammalian cell is about molecule is (A) 1 mM (B) 2 mM (A) Thymine (B) Uracil (C) 0.1 mM (D) 0.2 mM (C) Xanthine (D) Hypoxanthine 14. The nucleic acid base found in mRNA but 22. RNA does not contain not in DNA is (A) Uracil (B) Adenine (A) Adenine (B) Cytosine (C) Thymine (D) Ribose (C) Guanine (D) Uracil 23. The sugar moiety present in RNA is 15. In RNA moleule ‘Caps’ (A) Ribulose (B) Arabinose (A) Allow tRNA to be processed (C) Ribose (D) Deoxyribose (B) Are unique to eukaryotic mRNA (C) Occur at the 3’ end of tRNA 24. In RNA molecule (D) Allow correct translation of prokaryotic mRNA (A) Guanine content equals cytosine 16. In contrast to eukaryotic mRNA, (B) Adenine content equals uracil prokaryotic mRNA (C) Adenine content equals guanine (A) Can be polycistronic (D) Guanine content does not necessarily equal (B) Is synthesized with introns its cytosine content. (C) Can only be monocistronic 25. Methylated purines and pyrimidines are (D) Has a poly A tail characteristically present in 17. The size of small stable RNA ranges from (A) mRNA (B) hnRNA (A) 0–40 nucleotides (C) tRNA (D) rRNA (B) 40–80 nucleotides 26. Thymine is present in (C) 90–300 nucleotides (A) tRNA (B) Ribosomal RNA (D) More than 320 nucleotides (C) Mammalian mRNA(D) Prokaryotic mRNA 18. The number of small stable RNAs per cell 27. The approximate number of nucleotides ranges from in tRNA molecule is (A) 10–50,000 (A) 25 (B) 50 (B) 50,000–1,00,000 (C) 75 (D) 100 (C) 1,00,000–10,00,000 (D) More than 10 lakhs 28. In every cell, the number of tRNA mole- cules is at least 19. Molecular weight of heterogenous nuclear RNA (hnRNA) is (A) 10 (B) 20 (A) More than 107 (B) 105 to 106 (C) 30 (D) 40 4 5 4 (C) 10 to 10 (D) Less than 10 29. The structure of tRNA appears like a 20. In RNA molecule guanine content does not (A) Helix (B) Hair pin necessarily equal its cytosine content nor (C) Clover leaf (D) Coil does its adenine content necessarily equal its uracil content since it is a 30. Although each specific tRNA differs from the (A) Single strand molecule others in its sequence of nucleotides, all tRNA molecules contain a base paired stem that (B) Double stranded molecule terminates in the sequence CCA at (C) Double stranded helical molecule (A) Termini (B) Termini (D) Polymer of purine and pyrimidine ribonucleo- 3′ 5′ tides (C) Anticodon arm (D) 53 ′′ -Termini NUCLEIC ACIDS 237

31. Transfer RNAs are classified on the basis 41. DNA rich in G-C pairs have of the number of base pairs in (A) 1 Hydrogen bond (B) 2 Hydrogen bonds (A) Acceptor arm (B) Anticodon arm (C) 3 Hydrogen bonds (D) 4 Hydrogen bonds (C) D arm (D) Extra arm 42. The fact that DNA bears the genetic 32. In tRNA molecule D arm is named for the information of an organism implies that presence of the base: (A) Base composition should be identical from (A) Uridine (B) Pseudouridine species to species (C) Dihydrouridine (D) Thymidine (B) DNA base composition should charge with 33. The acceptor arm in the tRNA molecule has age (A) 5 Base pairs (B) 7 Base pairs (C) DNA from different tissues in the same organism should usually have the same base (C) 10 Base pairs (D) 20 Base pairs composition 34. In tRNA molecule, the anticodon arm (D) DNA base composition is altered with possesses nutritional state of an organism (A) 5 Base pairs (B) 7 Base pairs 43. The width (helical diameter) of the double (C) 8 Base pairs (D) 10 Base pairs helix in B-form DNA in nm is 35. The T ψ C arm in the tRNA molecule (A) 1 (B) 2 possesses the sequence (C) 3 (D) 4 (A) T, pseudouridine and C 44. The number of base pair in a single turn (B) T, uridine and C of B-form DNA about the axis of the (C) T, dihydrouridine and C molecule is (D) T, adenine and C (A) 4 (B) 8 36. Double helical structure model of the DNA (C) 10 (D) 12 was proposed by 45. The distance spanned by one turn of B- (A) Pauling and Corey form DNA is (B) Peter Mitchell (A) 1.0 nm (B) 2.0 nm (C) Watson and Crick (C) 3.0 nm (D) 3.4 nm (D) King and Wooten 46. In a DNA molecule the thymine concen- 37. DNA does not contain tration is 30%, the guanosine concentra- (A) Thymine (B) Adenine tion will be (C) Uracil (D) Deoxyribose (A) 10% (B) 20% 38. The sugar moiety present in DNA is (C) 30% (D) 40% (A) Deoxyribose (B) Ribose 47. IN a DNA molecule, the guanosine content (C) Lyxose (D) Ribulose is 40%, the adenine content will be 39. DNA rich in A-T pairs have (A) 10% (B) 20% (A) 1 Hydrogen bond (B) 2 Hydrogen bonds (C) 30% (D) 40% (C) 3 Hydrogen bonds(D) 4 Hydrogen bonds 48. An increased melting temperature of du- 40. In DNA molecule plex DNA results from a high content of (A) Guanine content does not equal cytosine content (A) Adenine + Guanine (B) Adenine content does not equal thymine content (B) Thymine + Cytosine (C) Adenine content equals uracil content (C) Cytosine + Guanine (D) Guanine content equals cytosine content (D) Cytosine + Adenine 238 MCQs IN BIOCHEMISTRY

49. A synthetic nucleotide analogue, 4-hydro- 56. In purine biosynthesis carbon atoms at 4 xypyrazolopyrimidine is used in the and 5 position and N at 7 position are treatment of contributed by (A) Acute nephritis (A) Glycine (B) Glutamine (B) Gout (C) Alanine (D) Threonine (C) Cystic fibrosis of lung 57. N10-formyl and N5N10-methenyl tetrahy- (D) Multiple myeloma drofolate contributes purine carbon atoms 50. A synthetic nucleotide analogue, used in at position the chemotherapy of cancer and viral (A) 4 and 6 (B) 4 and 5 infections is (C) 5 and 6 (D) 2 and 8 (A) Arabinosyl cytosine (B) 4-Hydroxypyrazolopyrimidine 58. In purine nucleus nitrogen atom at 1 (C) 6-Mercaptopurine position is derived from (D) 6-Thioguanine (A) Aspartate (B) Glutamate (C) Glycine (D) Alanine 51. Histamine is formed from histidine by the enzyme histidine decarboxylase in the 59. The key substance in the synthesis of presence of purine, phosphoribosyl pyrophosphate is (A) NAD (B) FMN formed by

(C) HS-CoA (D) B6-PO4 (A) α-D-ribose 5-phosphate 52. Infantile convulsions due to lesser (B) 5-phospho β-D-ribosylamine formation of gamma amino butyric acid (C) D-ribose from glutamic acid is seen in the de- (D) Deoxyribose ficiency of 60. In purine biosynthesis ring closure in the (A) Glutamate-dehydrogenase molecule formyl glycinamide ribosyl-5- (B) Pyridoxine phosphate requires the cofactors: (C) Folic acid (A) ADP (B) NAD (D) Thiamin (C) FAD (D) ATP and Mg++ 53. Which of the following amino acids pro- duce a vasoconstrictor on decarboxyla- 61. Ring closure of formimidoimidazole tion? carboxamide ribosyl-5-phosphate yields the first purine nucleotide: (A) Histidine (B) Tyrosine (C) Threonine (D) Arginine (A) AMP (B) IMP (C) XMP (D) GMP 54. The degradation of RNA by produces 62. The cofactors required for synthesis of (A) Nucleoside 2-Phosphates adenylosuccinate are (B) Nucleoside 5′-phosphates (A) ATP, Mg++ (B) ADP (C) Oligonucleosides (C) GTP, Mg++ (D) GDP (D) Nucleoside 3′-phosphate and oligonucleotide 63. Conversion of inosine monophosphate to 55. Intestinal nucleosidases act on nucleo- xanthine monophosphate is catalysed by sides and produce (A) IMP dehydrogenase (A) Purine base only (B) Phosphate only (B) Formyl transferase (C) Sugar only (D) Purine or pyrimidine (C) Xanthine-guanine phosphoribosyl transferase bases and sugars (D) Adenine phosphoribosyl transferase NUCLEIC ACIDS 239

64. Phosphorylation of adenosine to AMP is 71. Purine biosynthesis is inhibited by catalysed by (A) Aminopterin (B) Tetracyclin (A) (C) Methotrexate (D) Chloramphenicol (B) Deoxycytidine kinase (C) Adenylosuccinase 72. Pyrimidine and purine nucleoside bio- (D) Adenylosuccinate synthetase synthesis share a common precursor: (A) PRPP (B) Glycine 65. The major determinant of the overall rate of denovo purine nucleotide biosynthesis (C) Fumarate (D) Alanine is the concentration of 73. Pyrimidine biosynthesis begins with the (A) 5-phosphoribosyl 1-pyrophosphate formation from glutamine, ATP and CO2, (B) 5-phospho β-D-ribosylamine of (C) Glycinamide ribosyl-5-phosphate (A) Carbamoyl aspartate (D) Formylglycinamide ribosyl-5-phosphate (B) Orotate 66. An enzyme which acts as allosteric reg- (C) Carbamoyl phosphate ulator and sensitive to both phosphate (D) Dihydroorotate concentration and to the purine nucle- otides is 74. The two nitrogen of the pyrimidine ring (A) PRPP synthetase are contributed by (B) PRPP glutamyl midotransferase (A) Ammonia and glycine (C) HGPR Tase (B) Asparate and carbamoyl phosphate (D) Formyl transferase (C) Glutamine and ammonia 67. PRPP glutamyl amidotransferase, the first (D) Aspartate and ammonia enzyme uniquely committed to purine 75. A cofactor in the conversion of dihydro- synthesis is feed back inhibited by orotate to orotic acid, catalysed by the (A) AMP (B) IMP enzyme dihydroorotate dehydrogena- (C) XMP (D) CMP se is 68. Conversion of formylglycinamide ribosyl- (A) FAD (B) FMN 5-phosphate to formyl-glycinamide (C) NAD (D) NADP ribosyl-5-phosphate is inhibited by (A) Azaserine (B) Diazonorleucine 76. The first true pyrimidine ribonucleotide synthesized is (C) 6-Mercaptopurine (D) Mycophenolic acid (A) UMP (B) UDP 69. In the biosynthesis of purine nucleotides the AMP feed back regulates (C) TMP (D) CTP (A) Adenylosuccinase 77. UDP and UTP are formed by phosphory- (B) Adenylosuccinate synthetase lation from (C) IMP dehydrogenase (A) AMP (B) ADP (D) HGPR Tase (C) ATP (D)GTP

70. 6-Mercapto purine inhibits the conversion 78. Reduction of ribonucleotide diphosphates of (NDPs) to their corresponding deoxy (A) IMP→ XMP ribonucleotide diphosphates (dNDPs) (B) Ribose 5 phosphate → PRPP involves (C) PRPP → 5-phospho → β -D-ribosylamine (A) FMN (B) FAD (D) Glycinamide ribosyl 5-phosphate → formylg- (C) NAD (D) NADPH lycinamide ribosyl-5-phosphate 240 MCQs IN BIOCHEMISTRY

79. Conversion of deoxyuridine monophos- 86. The enzyme aspartate transcarbamoy- phate to thymidine monophosphate is lase of pyrimidine biosynthesis is inhibit- catalysed by the enzyme: ed by (A) (A) ATP (B) ADP (C) AMP (D) CTP (B) Thymidylate synthetase (C) CTP synthetase 87. In humans end product of purine cata- bolism is (D) Orotidylic acid decarboxylase (A) Uric acid (B) Urea 80. d-UMP is converted to TMP by (C) Allantoin (D) Xanthine (A) Methylation (B) Decarboxylation 88. In humans purine are catabolised to uric (C) Reduction (D) Deamination acid due to lack of the enzyme: 81. UTP is converted to CTP by (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase (A) Methylation (B) Isomerisation (C) Amination (D) Reduction 89. In mammals other than higher primates uric acid is converted by 82. Methotrexate blocks the synthesis of (A) Oxidation to allantoin thymidine monophosphate by inhibiting (B) Reduction to ammonia the activity of the enzyme: (C) Hydrolysis to ammonia (A) (D) Hydrolysis to allantoin (B) Orotate phosphoribosyl transferase 90. The correct sequence of the reactions of (C) Ribonucleotide reductase catabolism of adenosine to uric acid is (D) (A) Adenosine→hypoxanthine→xanthine→uric 83. A substrate for enzymes of pyrimidine acid nucleotide biosynthesis is (B) Adenosine→xanthine→inosine→uric acid (C) Adenosine→inosine→hypoxanthine→ xanthine (A) Allopurinol (B) Tetracylin uric acid (C) Chloramphenicol (D) Puromycin (D) Adenosine→xanthine→inosine→hypo- 84. An enzyme of pyrimidine nucleotide bio- xanthine uric acid synthesis sensitive to allosteric regulation 91. Gout is a metabolic disorder of catabolism is of (A) Aspartate transcarbamoylase (A) Pyrimidine (B) Purine (B) Dihydroorotase (C) Alanine (D) Phenylalanine (C) Dihydroorotate dehydrogenase 92. Gout is characterized by increased plasma (D) Orotidylic acid decarboxylase levels of (A) Urea (B) Uric acid 85 An enzyme of pyrimidine nucleotides biosynthesis regulated at the genetic (C) Creatine (D) Creatinine level by apparently coordinate repression 93. Lesch-Nyhan syndrome, the sex linked and derepression is recessive disorder is due to the lack of the enzyme: (A) Carbamoyl phosphate synthetase (A) Hypoxanthine-guanine phosphoribosyl (B) Dihydroorotate dehydrogenase transferse (C) (B) Xanthine oxidase (D) Deoxycytidine kinase (C) Adenine phosphoribosyl transferase (D) NUCLEIC ACIDS 241

94. Lesch-Nyhan syndrome, the sex linked, 101. Genetic information flows from recessive absence of HGPRTase, may lead (A) DNA to DNA to (B) DNA to RNA (A) Compulsive self destructive behaviour with (C) RNA to cellular proteins elevated levels of urate in serum (D) DNA to cellular proteins (B) Hypouricemia due to liver damage (C) Failure to thrive and megaloblastic anemia 102. Genetic code is (D) Protein intolerance and hepatic encephalop- (A) Collection of codon athy (B) Collection of amino acids (C) Collection of purine nucleotide 95. The major catabolic product of pyrim- idines in human is (D) Collection of pyrimidine nucleotide (A) β-Alanine (B) Urea 103. Degeneracy of genetic code implies that (C) Uric acid (D) Guanine (A) Codons do not code for specific amino acid 96. Orotic aciduria type I reflects the deficien- (B) Multiple codons must decode the same amino cy of enzymes: acids (A) Orotate phosphoribosyl transferase and (C) No anticodon on tRNA molecule orotidylate decarboxylase (D) Specific codon decodes many amino acids (B) Dihydroorotate dehydrogenase 104. Genetic code is (C) Dihydroorotase (A) Overlapping (B) Non-overlapping (D) Carbamoyl phosphate synthetase (C) Not universal (D) Ambiguous 97. Orotic aciduria type II reflects the deficien- cy of the enzyme: 105. mRNA is complementary to the nucleotide sequence of (A) Orotate phosphoribosyl transferase (B) Orotidylate decarboxylase (A) Coding strand (B) Ribosomal RNA (C) Dihydroorotase (C) tRNA (D)Template strand (D) Dihydroorotate dehydrogenase 106. In DNA replication the enzyme required 98. An autosomal recessive disorder, xanthi- in the first step is nuria is due to deficiency of the enzymes: (A) DNA directed polymerase (A) Adenosine deaminase (B) Unwinding proteins (B) Xanthine oxidase (C) DNA polymerase (C) HGPRTase (D) DNA ligase (D) Transaminase 107. The smallest unit of DNA capable of cod- 99. Enzymic deficiency in βββ-aminoisobutyric ing for the synthesis of a polypeptide is aciduria is (A) Operon (B) Repressor gene (A) Adenosine deaminase (C) Cistron (D) Replicon (B) Xanthine oxidase 108. Termination of the synthesis of the RNA (C) Orotidylate decarboxylase molecule is signaled by a sequence in the (D) Transaminase template strand of the DNA molecule, a 100. Polysomes lack in signal that is recognized by a termination (A)DNA (B) mRNA protein, the (C) rRNA (D) tRNA (A) Rho (ρ) factor (B) σ factor (C) δ factor (D) ε factor 242 MCQs IN BIOCHEMISTRY

109. After termination of the synthesis of RNA 114. All pribnow boxes are variants of the molecule, the core enzymes separate from sequence: the DNA template. The core enzymes then (A) 5′–TATAAT –3′ (B) 5′–GAGCCA –3′ recognize a promoter at which the syn- (C) 5′–UAACAA –3′ (D) 5′–TCCTAG –3′ thesis of a new RNA molecule commenc- es, with the assistance of 115. 5’-Terminus of mRNA molecule is capped (A) Rho (ρ) factor (B) δ factor with (C) β factor (D) σ factor (A) Guanosine triphosphate 110. In the process of transcription in bacterial (B) 7-Methylguanosine triphophate cells (C) Adenosine triphosphate (A) Initiation requires rho protein (D) Adenosine diphosphate (B) RNA polymerase incorporates methylated 116. The first codon to be translated on mRNA bases in correct sequence is (C) Both the sigma unit and core enzymes of RNA (A) AUG (B) GGU polymerase are required for accurate (C) GGA (D) AAA promotor site binding (D) is necessary for initiation 117. AUG, the only identified codon for methio- nine is important as 111. The correct statement concerning RNA and DNA is (A) A releasing factor for peptide chains (B) A chain terminating codon (A) RNA polymerase use nucleoside diphosphates (C) Recognition site on tRNA (B) RNA polymerase require primers and add (D) A chain initiating codon bases at 5’ end of the growing polynucleotide 118. In biosynthesis of proteins the chain chain terminating codons are (C) DNA polymerases can add nucleotides at both (A) UAA, UAG and UGA ends of the chain (B) UGG, UGU and AGU (D) All RNA and DNA polymerases can add nucleotides only at the 3’ end of the growing (C) AAU, AAG and GAU polynucleotide chain (D) GCG, GCA and GCU 112. The eukaryotic nuclear chromosomal DNA 119. The formation of initiation complex during (A) Is a linear and unbranched molecule protein synthesis requires a factor: (B) Is not associated with a specific membranous (A) IF-III (B) EF-I organelle (C) EF-II (D) IF-I (C) Is not replicated semiconservatively 120. The amino terminal of all polypeptide (D) Is about of the same size as each prokaryotic chain at the time of synthesis in E. coli is chromoses tagged to the amino acid residue: 113. The function of a repressor protein in an (A) Methionine (B) Serine operon system is to prevent synthesis by (C) N-formyl methinine (D) N-formal serine binding to 121. Initiation of protein synthesis begins with (A) The ribosome binding of (B) A specific region of the operon preventing transcription of structural genes (A) 40S ribosomal unit on mRNA (C) The RNA polymerase (B) 60S ribosomal unit (D) A specific region of the mRNA preventing (C) Charging of tRNA with specific amino acid translation to protein (D) Attachment of aminoacyl tRNA on mRNA NUCLEIC ACIDS 243

122. Initiation of protein synthesis requires 129. The nucleophilic attack on the esterified (A) ATP (B) AMP carboxyl group of the peptidyl-tRNA occupying the P site and the ααα-amino (C) GDP (D)GTP group of the new amino acyl tRNA, the 123. The enzyme amino acyl tRNA synthetase number of ATP required by the amino acid is involved in on the charged tRNA is (A) Dissociation of discharged tRNA from 80S (A) Zero (B) One ribosome (C) Two (D) Four (B) Charging of tRNA with specific amino acids 130. Translocation of the newly formed (C) Termination of protein synthesis peptidyl tRNA at the A site into the empty (D) Nucleophilic attack on esterified carboxyl P site involves group of peptidyl tRNA (A) EF-II, GTP 124. In the process of activation of amino acids (B) EF-I, GTP for protein synthesis, the number of high (C) EF-I, GDP energy phosphate bond equivalent (D) , GTP utilised is (A) 0 (B) 1 131. In eukaryotic cells (C) 2 (D) 4 (A) Formylated tRNA is important for initiation of translation 125 Translation results in a product known as (B) Cyclohexamide blocks elongation during (A) Protein (B) tRNA translation (C) mRNA (D) rRNA (C) Cytosolic ribosomes are smaller than those found in prokaryotes 126. In the process of elongation of chain binding of amino acyl tRNA to the A site (D) Erythromycin inhibits elongation during requires translation (A) A proper codon recognition 132. The mushroom poison amanitin is an (B) GTP inhibitor of (C) EF-II (A) Protein synthesis (B) mRNA synthesis (D) GDP (C) DNA synthesis (D) Adenosine synthesis

127. The newly entering amino acyl tRNA into 133. Tetracylin prevents synthesis of polypep- A site requires tide by (A) EF-II (B) Ribosomal RNA (A) Blocking mRNA formation from DNA (C) mRNA (D) EF-I (B) Releasing peptides from mRNA-tRNA complex (C) Competing with mRNA for ribosomal binding 128. The ααα-amino group of the new amino acyl sites tRNA in the A site carries out a nucleo- philic attack on the esterified carboxyl (D) Preventing binding of aminoacyl tRNA group of the peptidyl tRNA occupying the 134. In prokaryotes, chloramphenicol P site. This reaction is catalysed by (A) Causes premature release of the polypeptide (A) DNA polymerase chain (B) RNA polymerase (B) Causes misreading of the mRNA (C) Peptidyl transferase (C) Depolymerises DNA (D) DNA ligase (D) Inhibits peptidyl transferase activity 244 MCQs IN BIOCHEMISTRY

135 Streptomycin prevents synthesis of poly- 144. The enzyme DNA ligase peptide by (A) Introduces superhelical twists (A) Inhibiting initiation process (B) Connects the end of two DNA chains (B) Releasing premature polypeptide (C) Unwinds the double helix (C) Inhibiting peptidyl transferase activity (D) Synthesises RNA primers (D) Inhibiting translocation 145. Restriction 136. Erythromycin acts on ribosomes and in- hibit (A) Cut RNA chains at specific locations (A) Formation of initiation complex (B) Excise introns from hnRNA (B) Binding of aminoacyl tRNA (C) Remove Okazaki fragments (C) Peptidyl transferase activity (D) Act as defensive enzymes to protect the host (D) Translocation bacterial DNA from DNA of foreign organisms 137. The binding of prokaryotic DNA depen- 146. The most likely lethal mutation is dent RNA polymerase to promoter sites (A) Substitution of adenine for cytosine of genes is inhibited by the antibiotic: (B) Insertion of one nucleotide (A) Puromycin (B) Rifamycin (C) Deletion of three nucleotides (C) Terramycin (D) Streptomycin (D) Substitution of cytosine for guanine 138. The gene which is transcribed during repression is 147. In the following partial sequence of mRNA, a mutation of the template DNA (A) Structural (B) Regulator results in a change in codon 91 to UAA. (C) Promoter (D) Operator The type of mutation is 139 The gene of lac operon which has constitu- 88 89 90 91 92 93 94 tive expression is GUC GAC CAG UAG GGC UAA CCG (A) i (B) c (A) Missene (B) Silent (C) z (D) p (C) Nonsense (D) Frame shit 140. The minimum effective size of an operator for lac repressor binding is 148. Restriction endonucleases recognize and cut a certain sequence of (A) 5 base pairs (B) 10 base pairs (C) 15 base pairs (D) 17 base pairs (A) Single stranded DNA (B) Double stranded DNA 141 To commence structural gene transcrip- (C) RNA tion the region which should be free on lac operation is (D) Protein (A) Promoter site (B) Operator locus 149. Positive control of induction is best (C) Y gene (D) A gene described as a control system in which an operon functions 142. In the lac operon concept, a protein mole- cule is (A) Unless it is switched off by a derepressed (A) Operator (B) Inducer repressor protein (C) Promoter (D) Repressor (B) Only after a repressor protein is inactivated by an inducer 143. The catabolite repression is mediated by (C) Only after an inducer protein, which can be a catabolite gene activator protein (CAP) inactivated by a corepressor, switches it on in conjunction with (D) Only after an inducer protein, which is (A) AMP (B) GMP activated by an inducer, switch it on (C) cAMP (D) Cgmp NUCLEIC ACIDS 245

150. Interferon 158. Defective enzyme in Hurler’s syndrome is (A) Is virus specific (A) α-L-diuronidase (B) Is a bacterial product (B) Iduronate sulphatase (C) Is a synthetic antiviral agent (C) Arylsulphatase B (D) Requires expression of cellular genes (D) C-acetyl transferase 159. Presence of arginine can be detected by 151. Repressor binds to DNA sequence and regulate the transcription. This sequence (A) Sakaguchi reaction is called (B) Million-Nasse reaction (A) Attenuator (B) Terminator (C) Hopkins-Cole reaction (C) Anti terminator (D) Operator (D) Gas chromatography 160. A nitrogenous base that does not occur 152. Okazaki fragment is related to in mRNA is (A) DNA synthesis (B) Protein synthesis (A) Cytosine (B) Thymine (C) mRNA formation (D) tRNA formation (C) Uracil (D) All of these 153. The region of DNA known as TATA BOX is 161. In nucleotides, phosphate is attached to the site for binding of sugar by (A) DNA polymerase (A) Salt bond (B) Hydrogen bond (B) DNA (C) Ester bond (D) Glycosidic bond (C) DNA dependent RNA polymerase 162. Cyclic AMP can be formed from (D) Polynucleotide phosphorylase (A) AMP (B) ADP 154. Reverse transcriptase is capable of (C) ATP (D) All of these synthesising 163. A substituted pyrimidine base of pharma- (A) RNA → DNA (B) DNA → RNA cological value is (C) RNA → RNA (D) DNA → DNA (A) 5-Iododeoxyuridine 155. A tetrovirus is (B) Cytisine arabinoside (C) 5-Fluorouracil (A) Polio virus (B) HIV (D) All of these (C) Herpes virus (D) Tobacco mosaic virus 164 The ‘transforming factor’ discovered by 156. Peptidyl transferase activity is located in Avery, McLeod and McCarty was later (A) Elongation factor found to be (B) A charged tRNA molecule (A) mRNA (B) tRNA (C) Ribosomal protein (C) DNA (D) None of these (D) A soluble cytosolic protein 165. In DNA, the complementary base of adenine is 157. Ultraviolet light can damage a DNA strand causing (A) Guanine (B) Cytosine (C) Uracil (D) Thymine (A) Two adjacent purine residue to form a covalently bounded dimer 166. In DNA, three hydrogen bonds are (B) Two adjacent pyrimidine residues to form formed between covalently bonded dimer (A) Adenine and guanine (C) Disruption of phosphodiesterase linkage (B) Adenine and thymine (D) Disruption of non-covalent linkage (C) Guanine and cytosine (D) Thymine and cytosine 246 MCQs IN BIOCHEMISTRY

167. Left handed double helix is present in 177. The number of hydrogen bonds between adenine and thymine in DNA is (A) Z-DNA (B) A-DNA (C) B-DNA (D) None of these (A) One (B) Two (C) Three (D) Four 168. Nuclear DNA is present in combination with 178. The complementary base of adenine in RNA is (A) Histones (B) Non-histones (A) Thymine (B) Cystosine (C) Both (A) and (B) (D) None of these (C) Guanine (D) Uracil 169. Number of guanine and cytosine residues 179. Extranuclear DNA is present in is equal in (A) Ribosomes (A) mRNA (B) tRNA (B) Endoplasmic reticulum (C) DNA (D) None of these (C) Lysosomes 170. Alkalis cannot hydrolyse (D) Mitochondria (A) mRNA (B) tRNA 180. Mitochondrial DNA is present in (C) rRNA (D)DNA (A) Bacteria (B) Viruses 171. Codons are present in (C) Eukaryotes (D) All of these (A) Template strand of DNA 181. Ribothymidine is present in (B) mRNA (A)DNA (B) tRNA (C) tRNA (C) rRNA (D) hnRNA (D) rRNA 182. Ten base pairs are present in one turn of 172. Amino acid is attached to tRNA at the helix in (A) 5’-End (B) 3’-End (A) A-DNA (B) B-DNA (C) C-DNA (D) Z-DNA (C) Anticodon (D) DHU loop 183. Transfer RNA transfers 173. In prokaryotes, the ribosomal subunits are (A) Information from DNA to ribosomes (B) Information from mRNA to cytosol (A) 30 S and 40 S (B) 40 S and 50 S (C) Amino acids from cytosol to ribosomes (C) 30 S and 50 S (D) 40 S and 60 S (D) Proteins from ribosomes to cytosol 174. Ribozymes are 184. Ceramidase is deficient in (A) Enzymes present in ribosomes (A) Fabry’s disease (B) Farber’s disease (B) Enzymes which combine the ribosomal (C) Krabbe’s disease (D) Tay-Sachs disease subunits (C) Enzymes which dissociate 185. Ceramide is present in all of the following except (D) Enzymes made up of RNA (A) Plasmalogens (B) Cerebrosides 175. The smallest RNA among the following is (C) Sulphatides (D) Sphingomyelin (A) rRNA (B) hnRNA 186. Nucleotides required for the synthesis of (C) mRNA (D) tRNA nucleic acids can be obtained from 176. The number of adenine and thymine bases (A) Dietary nucleic acids and nucleotides is equal in (B) De novo synthesis (A)DNA (B) mRNA (C) Salvage of pre-existing bases and nucleosides (C) tRNA (D) rRNA (D) De novo synthesis and salvage NUCLEIC ACIDS 247

187. De novo synthesis of purine nucleotide 196. All of the following enzymes are unique occurs in to purine nucleotide synthesis except (A) Mitochondria (B) Cytosol (A) PRPP synthetase (C) Microsmes (D) Ribosomes (B) PRPP glutamyl amido transferase 188. The nitrogen atoms for de novo synthesis (C) Adenylosuccinate synthetase of purine nucleotides are provided by (D) IMP dehydrogenase (A) Aspartate and glutamate 197. PRPP synthetase is allosterically inhibited (B) Aspartate and glycine by (C) Aspartate, glutamine and glycine (D) Aspartate, glutamate and glycine (A) AMP (B) ADP (C) GMP (D) All of these 189 For de novo synthesis of purine nucle- otides, glycine provides 198. An allosteric inhibitor of PRPP glutamyl (A) One nitrogen atom amido transferase is (B) One nitrogen and one carbon atom (A) AMP (B) ADP (C) Two carbon atoms (C) GMP (D) All of these (D) One nitrogen and two carbon atoms 199. An allosteric inhibitor of adenylosuccinate 190. For de novo synthesis of purine nucle- synthetase is otides, aspartate provides (A) AMP (B) ADP (A) Nitrogen 1 (B) Nitrogen 3 (C) GMP (D)GDP (C) Nitrogen 7 (D) Nitrogen 9 200. An allosteric inhibitor of IMP dehydroge- 191. In the purine nucleus, carbon 6 is contrib- uted by nase is (A) AMP (B) ADP (A) Glycine (B) CO2 (C) Aspartate (D) Glutamine (C) GMP (D)GDP 192. 5-Phosphoribosyl-1-pyrophosphate is 201. GMP is an allosteric inhibitor of all the required for the synthesis of following except (A) Purine nucleotides (B) Pyrimidine nucleotides (A) PRPP synthetase (C) Both (A) and (B) (D) None of these (B) PRPP glutamyl amido synthetase 193. Inosine monophophate is an intermediate (C) IMP dehydrogenase during the de novo synthesis of (D) Adenylosuccinate synthetase (A) AMP and GMP (B) CMP and UMP 202. AMP is an allosteric inhibitor of (C) CMP and TMP (D) All of these (A) PRPP synthetase 194. Xanthosine monophosphate is an (B) Adenylosucciante synthetase intermediate during de novo synthesis of (C) Both (A) and (B) (A) TMP (B) CMP (D) None of these (C) AMP (D)GMP 195. In the pathway of de novo synthesis of 203. The first reaction unique to purine nucleo- purine nucleotides, all the following are tide synthesis is catalysed by allosteric enzymes except (A) PRPP synthetase (A) PRPP glutamyl amido transferase (B) PRPP glutamyl amido transferase (B) Adenylosuccinate synthetase (C) Phosphoribosyl glycinamide synthetase (C) IMP dehydrogenase (D) Formyl transferase (D) Adenylosuccinase 248 MCQs IN BIOCHEMISTRY

204. Free purine bases which can be salvaged 211. The enzyme common to catabolism of all are the purines is (A) Adenine and guanine (A) Adenosine deaminase (B) Adenine and hypoxanthine (B) Purine nucleoside phosphorylase (C) Guanine and hypoxanthine (C) Guanase (D) Adenine, guanine and hypoxanthine (D) None of these

205. The enzyme required for salvage of free 212. Uric acid is the end product of purine as purine bases is well as protein catabolism in (A) Adenine phosphoribosyl transferase (A) Man (B) Fish (B) Hypoxanthine guanine phosphoribosyl (C) Birds (D) None of these transferase 213. Daily uric acid excretion in adult men is (C) Both (A) and (B) (A) 2–6 mg (B) 20–40 mg (D) None of these (C) 150–250 mg (D) 40–600 mg 206. Deoxycytidine kinase can salvage 214. Dietary purines are catabolised in (A) Adenosine (A) Liver (B) Kidneys (B) Adenosine and deoxyadenosine (C) Intesitnal mucosa (D) All of these (C) Adenosine and guanosine (D) Adenine and adenosine 215. De novo synthesis of pyrimidine nucle- otides occurs in 207. Adenosine kinase can salvage (A) Mitochondria (B) Cytosol (A) Adenosine (C) Microsomes (D) Ribosomes (B) Adenosine and deoxyadenosine (C) Adenosine and guanosine 216. An enzyme common to de novo synthesis of pyrimidine nucleotides and urea is (D) Adenine and adenosine (A) Urease 208. Salvage of purine bases is regulated by (B) Carbamoyl phosphate synthetase (A) Adenosine phosphoribosyl transferase (C) Aspartate transcarbamoylase (B) Hypoxanthine guanine phosphoribosyl (D) Argininosuccinase transferase (C) Availability of PRPP 217. The nitrogen atoms of pyrimidine nucleus are provided by (D) None of these (A) Glutamate 209. The available PRPP is used preferentially (B) Glutamate and aspartate for (C) Glutamine (A) De novo synthesis of purine nucleotides (D) Glutamine and aspartate (B) De novo synthesis of pyrimidine nucleotides (C) Salvage of purine bases 218. The carbon atoms of pyrimidine nucleus are provided by (D) Salvage of pyrimidine bases (A) Glycine and aspartate 210. The end product of purine catabolism in (B) CO and aspartate man is 2 (C) CO and glutamate (A) Inosine (B) Hypoxanthine 2 (D) CO and glutamine (C) Xanthine (D) Uric acid 2 NUCLEIC ACIDS 249

219. Nitrogen at position 1 of pyrimidine nu- 228. For the synthesis of TMP from dump, a cleus comes from coenzyme is required which is (A) Glutamine (B) Glutamate (A) N10- Formyl tetrahydrofolate (C) Glycine (D) Aspartate (B) N5- Methyl tetrahydrofolate 220. Nitrogen at position 3 of pyrimidine nu- (C) N5, N10- Methylene tetrahydrofolate cleus comes from (D) N5- Formimino tetrahydrofolate (A) Glutamine (B) Glutamate 229. All the enzymes required for de novo (C) Glycine (D) Aspartate synthesis of pyrimidine nucleotides are 221. The carbon atom at position 2 of pyrimi- cytosolic except dine nucleus is contributed by (A) Carbamoyl phosphate synthetase (A) CO2 (B) Glycine (B) Aspartate transcarbamoylase (C) Aspartate (D) Glutamine (C) Dihydro-orotase 222. Aspartate contributes the following (D) Dihydro-orotate dehydrogenase carbon atoms of the pyrimidine nucelus: 230. During de novo synthesis of pyrimidine (A) C and C (B) C and C 2 4 5 6 nucleotides, the first ring compound to be (C) C2, C4 and C6 (D) C4, C5 and C6 formed is 223. The first pyrimidine nucleotide to be (A) Carbamoyl aspartic acid formed in de novo synthesis pathway is (B) Dihydro-orotic acid (A) UMP (B) CMP (C) Orotic acid (C) CTP (D)TMP (D) Orotidine monophosphate 224. Conversion of uridine diphosphate into 231. Tetrahydrofolate is required as a coen- deoxyuridine diphosphate requires all the following except zyme for the synthesis of (A) Ribonucleotide reductase (A) UMP (B) CMP (B) Thioredoxin (C) TMP (D) All of these (C) Tetrahydrobiopterin 232. All of the following statements about (D) NADPH are true except: 225. Amethopterin and aminopterin decrease (A) It requires NADH as a coenzyme the synthesis of (B) Its substrates are ADP, GDP, CDP and UDP (A) TMP (B) UMP (C) It is activated by ATP (C) CMP (D) All of these (D) It is inhibited by dADP

226. For synthesis of CTP and UTP, the amino 233. De novo synthesis of pyrimidine nucle- group comes from otides is regulated by (A) Amide group of Asparagine (A) Carbamoyl phosphate synthetase (B) Amide group of glutamine (B) Aspartate transcarbamoylase (C) α-Amino group of glutamine (C) Both (A) and (B) (D) α-Amino group of glutamate (D) None of these 227. CTP synthetase forms CTP from 234. Cytosolic carbamoyl phosphate synthe- (A) CDP and inorganic phosphate tase is inhibited by (B) CDP and ATP (A) UTP (B) CTP (C) UTP and glutamine (C) PRPP (D) TMP (D) UTP and glutamate 250 MCQs IN BIOCHEMISTRY

235. Cytosolic carbamoyl phosphate syn- 244. All the following statements about thetase is activated by primary gout are true except (A) Glutamine (B) PRPP (A) Its inheritance is X-linked recessive (C) ATP (D) Aspartate (B) It can be due to increased activity of PRPP synthetase 236. Aspartate transcarbamoylase is inhibited by (C) It can be due to increased activity of hypox- anthine guanine phosphoribosyl transferase (A) CTP (B) PRPP (D) De novo synthesis of purines is increased in it (C) ATP (D)TMP 245. All of the following statements about uric 237. The following cannot be salvaged in hu- acid are true except man beings: (A) It is a catabolite of purines (A) Cytidine (B) Deoxycytidine (B) It is excreted by the kidneys (C) Cytosine (D) Thymidine (C) It is undissociated at pH above 5.8 238. β -Aminoisobytyrate is formed from ca- (D) It is less soluble than sodium urate tabolism of 246. In inherited deficiency of hypoxanthine (A) Cytosine (B) Uracil guanine phosphoribosyl transferase (C) Thymine (D) Xanthine (A) De novo synthesis of purine nucleotides is 239. Free ammonia is liberated during the decreased catabolism of (B) Salvage of purines is decreased (A) Cytosine (B) Uracil (C) Salvage of purines is increased (C) Thymine (D) All of these (D) Synthesis of uric acid is decreased 247. All of the following statements about uric 240. β -Alanine is formed from catabolism of acid are true except (A) Thymine (A) It can be formed from allantoin (B) Thymine and cytosine (B) Formation of uric acid stones in kidneys can (C) Thymine and uracil be decreased by alkalinisation of urine (D) Cytosine and uracil (C) Uric acid begins to dissociate at pH above 5.8 241. The following coenzyme is required for (D) It is present in plasma mainly as monosodium catabolism of pyrimidine bases: urate (A) NADH (B) NADPH 248. All of the following statements about

(C) FADH2 (D) None of these primary gout are true except 242. Inheritance of primary gout is (A) Uric acid stones may be formed in kidneys (B) Arthritis of small joints occurs commonly (A) Autosomal recessive (B) Autosomal dominant (C) Urinary excretion of uric acid is decreased (C) X-linked recessive (D) It occurs predominantly in males (D) X-linked dominant 249. All of the following statements about allopurinol are true except 243. The following abnormality in PRPP synthetase can cause primary gout: (A) It is a structural analogue of uric acid (B) It can prevent uric acid stones in the kidneys (A) High Vmax (C) It increases the urinary excretion of xanthine (B) Low Km (C) Resistance to allosteric inihbition. and hypoxanthine (D) All of these (D) It is a competitive inhibitor of xanthine oxidase NUCLEIC ACIDS 251

250. Orotic aciduria can be controlled by (B) Ribonucleoside monophosphates (A) Oral administration of orotic acid (C) Ribonucleoside diphosphates (B) Decreasing the dietary intake of orotic acid (D) Ribonucleoside triphosphates (C) Decreasing the dietary intake of pyrimidines 258. An alternate substrate for orotate (D) Oral administration of uridine phosphoribosyl transferase is 251. All of the following occur in orotic aciduria (A) Allopurinol (B) Xanthine except (C) Hypoxanthine (D) Adenine

(A) Increased synthesis of pyrimidine nucleotides 259. Mammals other than higher primates do (B) Increased excretion of orotic acid in urine not suffer from gout because they (C) Decreased synthesis of cytidine triphosphate (A) Lack xanthine oxidase (D) Retardation of growth (B) Lack adenosine deaminase 252. Inherited deficiency of adenosine deami- (C) Lack purine nucleoside phosphorylase nase causes (D) Possess uricase

(A) Hyperuricaemia and gout 260. Hypouricaemia can occur in (B) Mental retardation (A) Xanthine oxidase deficiency (C) Immunodeficiency (B) Psoriasis (D) Dwarfism (C) Leukaemia 253. Complete absence of hypoxanthine gua- (D) None of these nine phospharibosyl transferase causes 261. Synthesis of DNA is also known as (A) Primary gout (B) Immunodeficiency (A) Duplication (B) Replication (C) Uric acid stones (D) Lesh-Nyhan syndrome (C) Transcription (D) Translation 254. Increased urinary excretion of orotic acid can occur in deficiency of 262. Replication of DNA is (A) Orotate phosphoribosyl transferase (A) Conservative (B) Semi-conservative (B) OMP decarboxylase (C) Non-conservative (D) None of these (C) Mitochondrial ornithine transcarbamoylase 263. Direction of DNA synthesis is (D) Any of the above (A) 5’ → 3’ (B) 3’ → 5’ 255. All of the following can occur in Lesch- (C) Both (A) and (B) (D) None of these Nyhan syndrome except 264. Formation of RNA primer: (A) Gouty arthritis (A) Precedes replication (B) Uric acid stones (B) Follows replication (C) Retarted growth (C) Precedes transcription (D) Self-mutiliating behaviour (D) Follows transcription 256. Inherited deficiency of purine nucleoside 265. Okazaki pieces are made up of phosphorylase causes (A) RNA (B) DNA (A) Dwarfism (B) Mental retardation (C) RNA and DNA (D) RNA and proteins (C) Immunodeficiency (D) Gout 266. Okazaki pieces are formed during the 257. Deoxyribonucleotides are formed by synthesis of reduction of (A) mRNA (B) tRNA (A) Ribonucleosides (C) rRNA (D) DNA 252 MCQs IN BIOCHEMISTRY

267. After formation of replication fork 275. The unwound strands of DNA are held (A) Both the new strands are synthesized disconti- apart by nuously (A) Single strand binding protein (B) One strand is synthesized continuously and (B) Double strand binding protein the other discontinuously (C) Rep protein (C) Both the new strands are synthesized (D) DNAA protein continuously (D) RNA primer is required only for the synthesis 276. Deoxyribonucleotides are added to RNA of one new strand primer by 268. An Okazaki fragment contains about (A) DNA polymerase I (B) DNA polymerase II (A) 10 Nucleotides (C) DNA polymerase III holoenzyme (B) 100 Nucleotides (C) 1,000 Nucleotides (D) All of these (D) 10,000 Nucleotides 277. Ribonucleotides of RNA primer are re- placed by deoxyribonucleotides by the 269. RNA primer is formed by the enzyme: enzyme: (A) Ribonuclease (B) Primase (A) DNA polymerase I (C) DNA polymerase I (D) DNA polymerase III (B) DNA polymerase II 270. In RNA, the complementary base of ade- (C) DNA polymerase III holoenzyme nine is (D) All of these (A) Cytosine (B) Guanine (C) Thymine (D) Uracil 278. DNA fragments are sealed by (A) DNA polymerase II 271. During replication, the template DNA is unwound (B) DNA ligase (C) DNA gyrase (A) At one of the ends (B) At both the ends (D) DNA topoisomerase II (C) At multiple sites (D) Nowhere 279. Negative supercoils are introduced in DNA 272. During replication, unwinding of double helix is initiated by by (A) DNAA protein (B) DnaB protein (A) (C) DNAC protein (D) Rep protein (B) DNA ligase (C) DNA gyrase 273. For unwinding of double helical DNA, (D) DNA polymerase III holoenzyme (A) Energy is provided by ATP (B) Energy is provided by GTP 280. Reverse transcriptase activity is present in the eukaryotic: (C) Energy can be provided by either ATP or GTP (D) No energy is required (A) DNA polymerase α (B) DNA polymerase γ 274. Helicase and DNAB protein cause (C) (A) Rewinding of DNA and require ATP as a (D) DNA polymerase II source of energy (B) Rewinding of DNA but do not require any 281. DNA polymerase III holoenzyme possesses source of energy (A) Polymerase activity (C) Unwinding of DNA and require ATP as a (B) 3’→5’ activity source of energy (C) 5’→3’ Exonuclease and polymerase activities (D) Unwinding of DNA but do not require any (D) 3’ 5’ Exonuclease and polymerase activities source of energy → NUCLEIC ACIDS 253

282. DNA polymerase I possesses 289. Melting temperature of DNA is the tempera- ture at which (A) Polymerase activity (B) 3’→5’ Exonuclease activity (A) Solid DNA becomes liquid (C) 5’→3’ Exonuclease activity (B) Liquid DNA evaporates (D) All of these (C) DNA changes from double helix into supercoiled DNA 283. 3’ →→→5’ Exonuclease activity of DNA (D) Native double helical DNA is denatured polymerase I 290. Melting temperature of DNA is increased (A) Removes ribonucleotides by its (B) Adds deoxyribonucleotides (A) A and T content (B) G and C content (C) Corrects errors in replication (C) Sugar content (D) Phosphate content (D) Hydrolyses DNA into mononucleotides 291. Buoynat density of DNA is increased by 284. All of the following statements about its RNA-dependent DNA polymerase are true (A) A and T content (B) G and C content except: (C) Sugar content (D) None of these (A) It synthesizes DNA using RNA as a template (B) It is also known as reverse transcriptase 292. Relative proportions of G and C versus A and T in DNA can be determined by its (C) It synthesizes DNA in 5’→3’ direction (D) It is present in all the viruses (A) Melting temperature (B) Buoyant density 285. Reverse transcriptase catalyses (C) Both (A) and (B) (A) Synthesis of RNA (D) None of these (B) Breakdown of RNA 293. Some DNA is present in mitochondria of (C) Synthesis of DNA (A) Prokaryotes (B) Eukaryotes (D) Breakdown of DNA (C) Both (A) and (B) (D) None of these 286. DNA A protein can bind only to 294. Satellite DNA contains (A) Positively supercoiled DNA (A) Highly repetitive sequences (B) Negatively supercoiled DNA (B) Moderately repetitive sequences (C) Both (A) and (B) (C) Non-repetitive sequences (D) None of these (D) DNA-RNA hybrids 287. DNA topoisomerase I of E. coli catalyses 295. Synthesis of RNA and a DNA template is (A) Relaxation of negatively supercoiled DNA known as (B) Relaxation of positively supercoiled DNA (A) Replication (B) Translation (C) Conversion of negatively supercoiled DNA (C) Transcription (D) Mutation into positively supercoiled DNA (D) Conversion of double helix into supercoiled 296. Direction of RNA synthesis is DNA (A) 5′ → 3’ (B) 3′ → 5’ 288. In mammalian cell cycle, synthesis of DNA (C) Both (A) and (B) (D) None of these occurs during 297. DNA-dependent RNA polymerase is a (A) S phase (B) G phase 1 (A) Monomer (B) Dimer (C) Mitotic Phase (D) G phase 2 (C) Trimer (D) Tetramer 254 MCQs IN BIOCHEMISTRY

298. DNA-dependent RNA polymerase requires (B) Methylation of some bases the following for its catalytic activity: (C) Formation of pseudouridine (A) Mg++ (B) Mn++ (D) Addition of C-C-A terminus at 5’ end (C) Both (A) and (B) (D) None of these 307. Post-transcriptional modification does not occur in 299. The initiation site for transcription is recognized by (A) Eukaryotic tRNA (B) Prokaryotic tRNA (C) Eukaryotic hnRNA (D) Prokaryotic mRNA (A) α−Subunit of DNA-dependent RNA polymerase (B) β−Subunit of DNA-dependent RNA polymerase 308. A consensus sequence on DNA, called TATA (C) Sigma factor box, is the site for attachment of (D) Rho factor (A) RNA-dependent DNA polymerase (B) DNA-dependent RNA polymerase 300. The termination site for transcription is (C) DNA-dependent DNA polymerase recognized by (D) DNA topoisomerase II (A) α−Subunit of DNA-dependent RNA polymerase 309. Polyadenylate tail is not present in mRNA (B) β−Subunit of DNA-dependent RNA polymerase synthesising (C) Sigma factor (A) Globin (B) Histone (D) Rho factor (C) Apoferritin (D) Growth hormone 301. Mammalian RNA polymerase I synthesises 310. Introns are present in DNA of (A) mRNA (B) rRNA (C) tRNA (D) hnRNA (A) Viruses (B) Bacteria (C) Man (D) All of these 302. Mammalian RNA polymerase III synthesises 311. A mammalian DNA polymerase among (A) rRNA (B) mRNA the following is (C) tRNA (D) hnRNA (A) DNA polymerase α 303. In mammals, synthesis of mRNA is (B) DNA polymerase I catalysed by (C) DNA polymerase II (A) RNA polymerase I (B) RNA polymerase II (D) DNA polymerase IV (C) RNA polymerase III(D) RNA polymerase IV 312. Mammalian DNA polymerase γ is located 304. Heterogeneous nuclear RNA is the in precursor of (A) Nucleus (B) Nucleolus (A) mRNA (B) rRNA (C) Mitochondria (D) Cytosol (C) tRNA (D) None of these 313. Replication of nuclear DNA in mammals 305. Post-transcriptional modification of hnRNA is catalysed by involves all of the following except (A) DNA polymerase (A) Addition of 7-methylguanosine triphosphate α cap (B) DNA polymerase β (B) Addition of polyadenylate tail (C) DNA polymerase γ (C) Insertion of nucleotides (D) DNA polymerase III (D) Deletion of introns 314. Primase activity is present in 306. Newly synthesized tRNA undergoes post- (A) DNA polymerase II transcriptional modifications which include (B) DNA polymerase α all the following except (C) DNA polymerase β (A) Reduction in size (D) DNA polymerase δ NUCLEIC ACIDS 255

315. The mammalian DNA polymerase (D) Are the sequences that intervene between involved in error correction is two genes (A) DNA polymerase α 323. All of the following statements about (B) DNA polymerase β post-transcriptional processing of tRNA are true except (C) DNA polymerase γ (A) Introns of some tRNA precursors are removed (D) DNA polymerase δ (B) CCA is added at 3′ end 316. Novobicin inhibits the synthesis of (C) 7-Methylguanosine triphosphate cap is added at 5′ end (A)DNA (B) mRNA (D) Some bases are methylated (C) tRNA (D) rRNA 324. ααα-Amanitin inhibits 317. Ciprofloxacin inhibits the synthesis of (A) DNA polymerase II of prokaryotes (A)DNA (B) mRNA (B) DNA polymerase α of eukaryotes (C) tRNA (D) rRNA (C) RNA polymerase II of eukaryotes 318. Ciprofloxacin inhibits (D) RNA-dependent DNA polymerase (A) DNA topisomerase II 325. Ciprofloxacin inhibits the synthesis of (B) DNA polymerase I (A) DNA in prokaryotes (C) DNA polymerase III (B) DNA in prokaryotes and eukaryotes (D) DNA gyrase (C) RNA in prokaryotes 319. Rifampicin inhibits (D) RNA in prokaryotes and eukaryotes (A) Unwinding of DNA 326. All of the following statements about (B) Initiation of replication bacterial promoters are true except (C) Initiation of translation (A) They are smaller than eukaryotic promoters (D) Initiation of transcription (B) They have two consensus sequences upstream 320. Actinomycin D binds to from the transcription star site (A) Double stranded DNA (C) TATA box is the site for attachment of RNA polymerase (B) Single stranded DNA (D) TATA box has a high melting temperature (C) Single stranded RNA (D) DNA-RNA hybrid 327. All of the following statements about eukaryotic promoters are true except 321. DNA contains some palindromic sequences which (A) They may be located upstream or down stream from the structural gene (A) Mark the site for the formation of replication (B) They have two consensus sequences forks (C) One consensus sequence binds RNA (B) Direct DNA polymerase to turn back to polymerase replicate the other strand (D) Mutations in promoter region can decrease the (C) Are recognized by restriction enzymes efficiency of transcription of the structural gene (D) Are found only in bacterial DNA 328. In sanger’s method of DNA sequence 322. Introns in genes determination, DNA synthesis is stopped (A) Encode the amino acids which are removed by using during post-translational modification (A) 1′, 2′- Dideoxyribonucleoside triphosphates (B) Encode signal sequences which are removed (B) 2 , 3 - Dideoxyribonucleoside triphosphates before secretion of the proteins ′ ′ (C) Are the non-coding sequences which are not (C) 2′, 4′- Dideoxyribonucleoside triphosphates translated (D) 2′, 5′ - Dideoxyribonucleoside triphosphates 256 MCQs IN BIOCHEMISTRY

329. tRNA genes have (C) They are identical in nuclear and (A) Upstream promoters mitochondrial DNA (D) They have no complementary anticodons (B) Downstream promoters (C) Intragenic promoters 337. A polycistronic mRNA can be seen in (D) No promoters (A) Prokaryotes (B) Eukaryotes 330. All of the following statements about (C) Mitochondria (D) All of these tRNA are true except 338. Non-coding sequence are present in the (A) It is synthesized as a large precursor genes of (B) It is processed in the nucelolus (A) Bacteria (B) Viruses (C) It has no codons or anticodons (C) Eukaryotes (D) All of these (D) Genes for rRNA are present in single copies 339. Non-coding sequences in a gene are known 331. Anticodons are present on as (A) Coding strand of DNA (A) Cistrons (B) Nonsense codons (B) mRNA (C) Introns (D) Exons (C) tRNA 340. Splice sites are present in (D) rRNA (A) Prokaryotic mRNA (B) Eukaryotic mRNA 332. Codons are present on (C) Eukaryotic hnRNA (D) All of these (A) Non-coding strand of DNA 341. The common features of introns include (B) hnRNA all the following except (C) tRNA (A) The base sequence begins with GU (D) None of these (B) The base sequence ends with AG (C) The terminal AG sequence is preceded by a 333. Nonsense codons are present on purine rich tract of ten nucleotides (A) mRNA (B) tRNA (D) An adenosine residue in branch site partici- (C) rRNA (D) None of these pates in splicing 334. Genetic code is said to be degenerate be- 342. A splice some contains all the following cause except (A) It can undergo mutations (A) hnRNA (B) snRNAs (B) A large proportion of DNA is non-coding (C) Some proteins (D) Ribosome (C) One codon can code for more than one amino 343. Self-splicing can occur in acids (A) Some precursors of rRNA (D) More than one codons can code for the same (B) Some precursors of tRNA amino acids (C) hnRNA 335. All the following statements about genetic (D) None of these code are correct except 344. Pribnow box is present in (A) It is degenerate (B) It is unambigous (A) Prokaryotic promoters (C) It is nearly universal(D) It is overlapping (B) Eukaryotic promoters 336. All of the following statements about (C) Both (A) and (B) nonsense codons are true except (D) None of these (A) They do not code for amino acids 345. Hogness box is present in (B) They act as chain termination signals (A) Prokaryotic promoters NUCLEIC ACIDS 257

(B) Eukaryotic promoters (D) Wobble results in incorporation of incorrect (C) Both (A) and (B) amino acids in the protein (D) None of these 351. The first amino acyl tRNA which initiates 346. CAAT box is present in translation in eukaryotes is (A) Prokaryotic promoters 10 bp upstream of (A) Mehtionyl tRNA transcription start site (B) Formylmethionyl tRNA (B) Prokaryotic promoters 35 bp upstream of (C) Tyrosinyl tRNA transcription start site (D) Alanyl tRNA (C) Eukaryotic promoters 25 bp upstream of transcription start site 352. The first amino acyl tRNA which initiates (D) Eukaryotic promoters 70–80 bp upstream of translation in prokaryotes is transcription start site (A) Mehtionyl tRNA 347. Eukaryotic promoters contain (B) Formylmethionyl tRNA (A) TATA box 25bp upstream of transcription start (C) Tyrosinyl tRNA site (D) Alanyl tRNA (B) CAAT box 70-80 bp upstream of transcription start site 353. In eukaryotes, the 40 S pre-initiation (C) Both (A) and (B) complex contains all the following (D) None of these initiation factors except (A) eIF-1A (B) eIF-2 348. All the following statements about tRNA are correct except (C) eIF-3 (D) eIF-4 (A) A given tRNA can be charged with only one 354. Eukaryotic initiation factors 4A, 4B and particular amino acid 4F bind to (B) The amino acid is recognized by the (A) 40 S ribosomal subunit anticodon of tRNA (B) 60 S ribosomal subunit (C) The amino acid is attached to end of tRNA (D) The anticodon of tRNA finds the comple- (C) mRNA mentary codon on mRNA (D) Amino acyl tRNA 349. All the following statements about 355. The codon which serves as translation charging of tRNA are correct except start signal is (A) It is catalysed by amino acyl tRNA synthetase (A) AUG (B) UAG (B) ATP is converted into ADP and Pi in this (C) UGA (D) UAA reaction 356. The first amino acyl tRNA approaches (C) The enzyme recognizes the tRNA and the 40 S ribosomal subunit in association with amino acid (A) eIF-1A and GTP (B) eIF-2 and GTP (D) There is a separate enzyme for each tRNA (C) eIF-2C and GTP (D) eIF-3 and GTP 350. All the following statements about recognition of a codon on mRNA by an 357. eIF-1A and eIF-3 are required anticodon on tRNA are correct except (A) For binding of amino acyl tRNA to 40 S (A) The recognition of the third base of the codon ribosomal subunit is not very precise (B) For binding of mRNA to 40 S ribosomal (B) Imprecise recognition of the third base results subunit in wobble (C) For binding of 60 S subunit to 40 S subunit (C) Wobble is partly responsible for the (D) To prevent binding of 60 S subunit to 40 S degeneracy of the genetic code subunit 258 MCQs IN BIOCHEMISTRY

358. eIF-4 A possesses 366. Puromycin causes premature chain (A) ATPase activity (B) GTPase activity termination in (C) Helicase activity (D) None of these (A) Prokaryotes (B) Eukaryotes (C) Both (A) and (B) (D) None of these 359. eIF-4 B (A) Binds to 3’ chain initiation codon on mRNA 367. Diphtheria toxin inhibits (B) Binds to 3’ end of mRNA (A) Prokaryotic EF-1 (B) Prokaryotic EF-2 (C) Binds to 5’ end of mRNA (C) Eukaryotic EF-1 (D) Eukaryotic EF-2 (D) Unwinds mRNA near its 5’ end 368. The proteins destined to be transported 360. Peptidyl transferase activity is present in out of the cell have all the following features except (A) 40 S ribosomal subunit (A) They possess a signal sequence (B) 60 S ribosomal subunit (B) Ribosomes synthesizing them are bound to (C) eEF-2 endoplasmic reticulum (D) Amino acyl tRNA (C) After synthesis, they are delivered into Golgi 361. After formation of a peptide bond, mRNA apparatus is translocated along the ribosome by (D) They are tagged with ubiquitin (A) eEF-1 and GTP 369. SRP receptors involved in protein export (B) eEF-2 and GTP are present on (C) Peptidyl transferase and GTP (A) Ribosomes (D) Peptidyl transferase and ATP (B) Endoplasmic reticulum 362. Binding of formylmehtionyl tRNA to 30 S (C) Golgi appartus ribosomal subunit of prokaryotes is (D) Cell membrane inhibited by 370. The signal sequence of proteins is cleaved (A) Streptomycin (B) Chloramphenicol off (C) Erythromycin (D) Mitomycin (A) On the ribosomes immediately after synthesis 363. Tetracyclines inhibit binding of amino acyl (B) In the endoplasmic reticulum tRNAs to (C) During processing in Golgi apparatus (A) 30 S ribosomal subunits (D) During passage through the cell membrane (B) 40 S ribosomal subunits 371. The half-life of a protein depends upon its (C) 50 S ribosomal subunits (A) Signal sequence (D) 60 S ribosomal subunits (B) N-terminus amino acid 364. Peptidyl transferase activity of 50 S (C) C-terminus amino acid ribosomal subunits is inhibited by (D) Prosthetic group (A) Rifampicin (B) Cycloheximide 372. Besides structural genes that encode (C) Chloramphenicol (D) Erythromycin proteins, DNA contains some regulatory 365. Erythromycin binds to 50 S ribosomal sub sequences which are known as unit and (A) Operons (B) Cistrons (A) Inhibits binding of amino acyl tRNA (C) Cis-acting elements (D) Trans-acting factors (B) Inhibits Peptidyl transferase activity 373. Inducers and repressors are (C) Inhibits translocation (A) Enhancer and silencer elements respectively (D) Causes premature chain termination (B) Trans-acting factors NUCLEIC ACIDS 259

(C) Cis-acting elements 381. Lac operon is a cluster of (D) Regulatory proteins (A) Three structural genes 374. cis-acting elements include (B) Three structural genes and their promoter (C) A regulatory gene, an operator and a (A) Steroid hormones (B) Calcitriol promoter (C) Histones (D) Silencers (D) A regulatory gene, an operator, a promoter 375. Silencer elements and three structural genes

(A) Are trans-acting factors 382. The regulatory i gene of lac operon (B) Are present between promoters and the (A) Is inhibited by lacotse structural genes (B) Is inhibited by its own product, the repressor (C) Decrease the expression of some structural protein genes (C) Forms a regulatory protein which increases (D) Encode specific repressor proteins the expression of downstream structural genes 376. trans-acting factors include (D) Is constitutively expressed

(A) Promoters (B) Repressors 383. RNA polymerase holoenzyme binds to lac (C) Enhancers (D) Silencers operon at the following site: 377. Enhancer elements have all the following (A) i gene (B) z gene features except (C) Operator locus (D) Promoter region

(A) They increase gene expression through a 384. Trancription of z, y and a genes of lac promoter operon is prevented by (B) Each enhancer activates a specific promoter (A) Lactose (B) Allo-lactose (C) They may be located far away from the (C) Repressor (D) cAMP promoter (D) They may be upstream or downstream from 385. Transcription of structural genes of lac the promoter operon is prevented by binding of the repressor tetramer to 378. Amplification of dihydrofolate reductase gene may be brought about by (A) i gene (B) Operator locus (C) Promoter (D) z gene (A) High concentrations of folic acid (B) Deficiency of folic acid 386. The enzymes encoded by z, y and a genes (C) Low concentration of thymidylate of lac operon are inducible, and their inducer is (D) Amethopterin (A) Lactose 379. Proteins which interact with DNA and (B) Allo-lactose affect the rate of transcription possess the following structural motif: (C) Catabolite gene activator protein (D) All of these (A) Helix-turn-helix motif (B) Zinc finger motif 387. Binding of RNA polymerase holoenzyme (C) Leucine zipper motif to the promoter region of lac operon is facilitated by (D) All of these (A) Catabolite gene activator protein (CAP) 380. Lac operon is a cluster of genes present in (B) cAMP (A) Human beings (B) E. coli (C) CAP-cAMP complex (C) Lambda phage (D) All of these (D) None of these 260 MCQs IN BIOCHEMISTRY

388. Lactose or its analogues act as positive (B) DNA polymerase I regulators of lac operon by (C) DNA ligase (A) Attaching to i gene and preventing its (D) All of these expression 396. Xeroderma pigmentosum results from a (B) Increasing the synthesis of catabolite gene defect in activator protein (A) uvr ABC excinuclease (C) Attaching to promoter region and facilitating (B) DNA polymerase I the binding of RNA polymerase holoenzyme (C) DNA ligase (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus (D) All of these 389. Expression of structural genes of lac operon 397. All the following statements about is affected by all the following except xeroderma pigmentosum are true except (A) Lactose or its analogues (A) It is a genetic disease (B) Repressor tetramer (B) Its inheritance is autosomal dominant (C) cAMP (C) uvr ABC excinuclease is defective in this (D) CAP-cAMP complex disease (D) It results in multiple skin cancers 390. The coding sequences in lac operon include 398. Substitution of an adenine base by guanine (A) i gene in DNA is known as (B) i gene, operator locus and promoter (A) Transposition (B) Transition (C) z, y and a genes (C) Transversion (D) Frameshift mutation (D) i, z, y and a genes 399. Substitution of a thymine base by 391. Mutations can be caused by adenine in DNA is known as (A) Ultraviolet radiation ((A) Transposition (B) Transition (B) Ionising radiation (C) Transversion (D) Frameshift mutation (C) Alkylating agents 400. A point mutation results from (D) All of these (A) Substitution of a base 392. Mutations can be caused by (B) Insertion of a base (A) Nitrosamine (B) Dimethyl sulphate (C) Deletion of a base (C) Acridine (D) All of these (D) All of these 393. Nitrosamine can deaminate 401. Substitution of a base can result in a (A) Cytosine to form uracil (A) Silent mutation (B) Mis-sense mutation (B) Adenine to form xanthine (C) Nonsense mutation (D) All of these (C) Guanine to form hypoxanthine 402. A silent mutation is most likely to result from (D) All of these (A) Substitution of the first base of a codon 394. Exposure of DNA to ultraviolet radiation (B) Substitution of the third base of a codon can lead to the formation of (C) Conversion of a nonsense codon into a sense (A) Adenine dimers (B) Guanine dimers codon (C) Thymine dimers (D) Uracil dimers (D) Conversion of a sense codon into a nonsense codon 395. Damage to DNA caused by ultraviolet radiation can be repaired by 403. The effect of a mis-sense mutation can be (A) uvr ABC excinuclease (A) Acceptable (B) Partially acceptable (C) Unacceptable (D) All of these NUCLEIC ACIDS 261

404. Amino acid sequence of the encoded (B) Change in reading frame of downstream protein is not changed in structural gene (A) Silent mutation (C) Decreased efficiency of transcription (B) Acceptable mis-sense mutation (D) All of these (C) Both (A) and (B) 412. Mitochondrial protein synthesis is inhibited (D) None of these by 405. Haemoglobin S is an example of a/an (A) Cycloheximide (B) Chloramphenicol (C) Diptheria toxin (D) None of these (A) Silent mutation (B) Acceptable mis-sense mutation 413. All of the following statements about (C) Unacceptable mis-sense mutation puromycin are true except (D) Partially acceptable mis-sense mutation (A) It is an alanyl tRNA analogue (B) It causes premature termination of protein 406. If the codon UAC on mRNA changes into synthesis UAG as a result of a base substitution in DNA, it will result in (C) It inhibits protein synthesis in prokaryotes (D) It inhibits protein synthesis in eukaryotes (A) Silent mutation (B) Acceptable mis-sense mutation 414. Leucine zipper motif is seen in some helical (C) Nonsense mutation proteins when leucine residues appear at every (D) Frameshift mutation (A) 3rd position (B) 5th position 407. Insertion of a base in a gene can cause (C) 7th position (D) 9th position (A) Change in reading frame 415. Zinc finger motif is formed in some (B) Garbled amino acid sequence in the proteins by binding of zinc to encoded protein (A) Two cysteine residues (C) Premature termination of translation (B) Two histidine residues (D) All of these (C) Two arginine residues 408. A frameshift mutation changes the (D) Two cysteine and two histidine residues or two reading frame because the genetic code pairs of two cysteine residues each (A) Is degenerate 416. Restriction endonucleases are present in (B) Is overlapping (A) Viruses (B) Bacteria (C) Has no punctuations (C) Eukaryotes (D) All of these (D) Is universal 417. Restriction endonucleases split 409. Suppressor mutations occur in (A) RNA (A) Structural genes (B) Promoter regions (B) Single stranded DNA (C) Silencer elements (D) Anticodons of tRNA (C) Double stranded DNA 410. Suppressor tRNAs can neutralize the (D) DNA-RNA hybrids effects of mutations in 418. Restriction endonucleases can recognise (A) Structural genes (B) Promoter regions (A) Palindromic sequences (C) Enhancer elements (D) All of these (B) Chimeric DNA 411. Mutations in promoter regions of genes (C) DNA-RNA hybrids can cause (D) Homopolymer sequences (A) Premature termination of translation 262 MCQs IN BIOCHEMISTRY

419. All of the following statements about (A) Southern blotting (B) Northern blotting restriction endonucleases are true except: (C) Both (A) and (B) (D) None of these (A) They are present in bacteria 427. An antibody probe is used in (B) They act on double stranded DNA (A) Southern blotting (B) Northern blotting (C) They recognize palindromic sequences (C) Western blotting (D) None of these (D) They always produce sticky ends 428. A particular protein in a mixture can be 420. Which of the following is a palindromic detected by sequence A) Southern blotting (B) Northern blotting (A) 5ATGCAG3′′−− (C) Western blotting (D) None of these (B) 3TACGTC5′′−− (C) 5CGAAGC3′′−− 429. The first protein synthesized by recom- binant DNA technology was (D) 3GCTTCG5′′−− (A) Streptokinase 421. In sticky ends produced by restriction (B) Human growth hormone endonucleases (C) Tissue plasminogen activator (A) The 2 strands of DNA are joined to each other (D) Human insulin

(B) The DNA strands stick to the restriction 430. For production of eukaryotic protein by endonuclease recombinant DNA technology in bacteria, (C) The ends of a double stranded fragment are the template used is overlapping (A) Eukaryotic gene (B) hnRNA (D) The ends of a double stranded fragment are (C) mRNA (D) All of these non overlapping 431. Monoclonal antibodies are prepared by 422. All of the following may be used as ex- cloning pression vectors except (A) Myeloma cells (B) Hybridoma cells (A) Plasmid (B) Bacteriophage (C) T-Lymphocytes (D) B-Lymphocytes (C) Baculovirus (D) E. coli 432. Myeloma cells are lacking in 423. A plasmid is a (A) TMP synthetase (A) Single stranded linear DNA (B) Formyl transferase (B) Single stranded circular DNA (C) HGPRT (C) Double stranded linear DNA (D) All of these (D) Double stranded circular DNA 433. Hybridoma cells are selected by culturing 424. Fragments of DNA can be identified by the them in a medium containing technique of (A) Adenine, guanine, cytosine and thymine (A) Western blotting (B) Eastern blotting (B) Adenine, guanine, cytosine and uracil (C) Northern blotting (D) Southern blotting (C) Hypoxanthine, aminopterin and thymine 425. A particular RNA in a mixture can be (D) Hypoxanthine, aminopterin and thymidine identified by 434. Myeloma cells and lymphocytes can be (A) Western blotting (B) Eastern blotting fused by using (C) Northern blotting (D) Southern blotting (A) Calcium chloride (B) Ethidium bromide 426. A radioactive isotope labeled cDNA probe (C) Polyethylene glycol (D) DNA polymerase is used in NUCLEIC ACIDS 263

435. Trials for gene therapy in human beings (A) E. coli (B) Yeast were first carried out, with considerable (C) T.aquaticus (D) Eukaryotes success, in a genetic disease called 444. Base sequence of DNA can be determined (A) Cystic fibrosis by (B) Thalassemia (A) Maxam-Gilbert method (C) Adenosine deaminase deficiency (B) Sanger’s dideoxy method (D) Lesch-Nyhan syndrome (C) Both (A) and (B) 436. Chimeric DNA (D) None of these (A) Is found in bacteriophages 445. From a DNA-RNA hybrid, DNA can be (B) Contains unrelated genes obtained by addition of (C) Has no restriction sites (A) DNA B protein and ATP (D) Is palindromic (B) Helicase and ATP 437. Which of the following may be used as a (C) DNA topoisomerase I cloning vector? (D) Alkali (A) Prokaryotic plasmid (B) Lambda phage 446. Optimum temperature of DNA polymerase (C) Cosmid (D) All of these of T. aquaticus is 438. The plasmid pBR322 has (A) 30°C (B) 37°C (A) Ampicillin resistance gene (C) 54°C (D) 72°C (B) Tetracycline resistance gene 447. In addition to Taq polymerase, poly- (C) Both (A) and (B) merase chain reaction requires all of the (D) None of these following except 439. Lambda phage can be used to clone DNA (A) A template DNA fragments of the size (B) Deoxyribonucleoside triphosphates (A) Upto 3 kilobases (B) Upto 20 kilobases (C) Primers (C) Upto 45 kilobases (D) Upto 1,000 kilobases (D) Primase 440. DNA fragments upto 45 kilobases in size 448. DNA polymerase of T.aquaticus is can be cloned in preferred to that of E. coli in PCR because (A) It replicates DNA more efficiently (A) Bacterial plasmids (B) It doesn’t require primers (B) Lambda phage (C) It is not denatured at the melting temperature (C) Cosmids of DNA (D) Yeast artificial chromosomes (D) It doesn’t cause errors in replication 441. A cosmid is a 449. Twenty cycles of PCR can amplify DNA: (A) Large bacterial plasmid (A) 220 fold (B) 202 fold (B) Viral plasmid (C) 20 x 2 fold (D) 20 fold (C) Hybrid of plasmid and phage (D) Yeast plasmid 450. Transgenic animals may be prepared by introducing a foreign gene into 442. Polymerase chain reaction can rapidly amplify DNA sequences of the size (A) Somatic cells of young animals (B) Testes and ovaries of animals (A) Upto 10 kilobases (B) Upto 45 kilobases (C) A viral vector and infecting the animals with (C) Upto 100 kilobases(D) Upto 1,000 kilobases the viral vector 443. The DNA polymerase commonly used in (D) Fertilised egg and implanting the egg into a polymerase chain reaction is obtained from foster mother 264 MCQs IN BIOCHEMISTRY

451. Yeast artificial chromosome can be used (A) Cysteine (B) Aspartate to amplify DNA sequences of the size (C) Glutamate (D) All of these (A) Upto 10 kb (B) Upto 45 kb 459. N-Formiminoglutamate is a metabolite of (C) Upto 100 kb (D) Upto 1,000 kb (A) Glutamate (B) Histidine 452. DNA finger printing is based on the (C) Tryptophan (D) Methionine presence in DNA of 460. Methylmalonyl CoA is a metabolite of (A) Constant number of tandem repeats (A) Valine (B) Leucine (B) Varibale number of tandem repeats (C) Isoleucine (D) All of these (C) Non-repititive sequences in each DNA (D) Introns in eukaryotic DNA 461. Homogentisic acid is formed from (A) Homoserine (B) Homocysteine 453. All the following statements about (C) Tyrosine (D) Tryptophan restriction fragment length polymor- phism are true except 462. Maple syrup urine disease results from (A) It results from mutations in restriction sites absence or serve deficiency of (B) Mutations in restriction sites can occur in (A) Homogentisate oxidase coding or non-coding regions of DNA (B) Phenylalanine hydroxylase (C) It is inherited in Mendelian fashion (C) Branched chain amino acid transaminase (D) It can be used to diagnose any genetic (D) None of these disease 463. Which of the following is present as a 454. Inborn errors of urea cycle can cause all marker in lysosomal enzymes to direct the following except them to their destination? (A) Vomiting (B) Ataxia (A) Glucose-6-phosphate (C) Renal failure (D) Mental retardation (B) Mannose-6-phosphate (C) Galactose-6-phosphate 455. Hyperammonaemia type I results from (D) N-Acetyl neuraminic acid congenital absence of (A) Glutamate dehydrogenase 464. Marfan’s syndrome results from a mutation in the gene coding: (B) Carbamoyl phosphate synthetase (C) Ornithine transcarbamoylase (A) Collagen (B) Elastin (D) None of these (C) Fibrillin (D) Keratin 456. Congenital deficiency of ornithine 465. All the following statements about transcarbamoylase causes fibronectin are true except (A) Hyperammonaemia type I (A) It is glycoprotein (B) Hyperammonaemia type II (B) It is a triple helix (C) Hyperornithinaemia (C) It is present in extra cellular matrix (D) Citrullinaemia (D) It binds with integrin receptors of cell 457. A ketogenic amino acid among the fol- 466. Fibronectin has binding sites for all of the lowing is following except (A) Leucine (B) Serine (A) Glycophorin (B) Collagen (C) Threonine (D) Proline (C) Heparin (D) Integrin receptor 458. Carbon skeleton of the following amino 467. Fibronectin is involved in acid can serve as a substance for gluconeogenesis (A) Cell adhension (B) Cell movement (C) Both (A) and (B) (D) None of these NUCLEIC ACIDS 265

468. Glycoproteins are marked for destruction 476. All the following statements about proto- by removal of their oncogenes are true except (A) Oligosaccharide prosthetic group (A) They are present in human beings (B) Sialic acid residues (B) They are present in healthy cells (C) Mannose residues (C) Proteins encoded by them are essential (D) N-terminal amino acids (D) They are expressed only when a healthy cell has been transformed into a cancer cell 469. Glycophorin is present in cell membranes of 477. Various oncogens may encode all of the (A) Erythrocytes (B) Platelets following except: (C) Neutrophils (D) Liver (A) Carcinogens 470. Selectins are proteins that can recognise (B) Growth factors specific (C) Receptors for growth factors (A) Carbohydrates (B) Lipids (D) Signal transducers for growth factors (C) Amino acids (D) Nucleotides 478. Ras proto-oncogene is converted into 471. Hunter’s syndrome results from absence of oncogene by (A) Hexosaminidase A (A) A point mutation (B) Iduronate sulphatase (B) Chromosomal translocation (C) (C) Insertion of a viral promoter upstream of the (D) Arylsulphatase B gene (D) Gene amplification 472. A cancer cell is characterized by (A) Uncontrolled cell division 479. Ras proto-oncogene encodes (B) Invasion of neighbouring cells (A) Epidermal growth factor (EGF) (C) Spread to distant sites (B) Receptor for EGF (D) All of these (C) Signal transducer for EGF (D) Nuclear transcription factor 473. If DNA of a cancer cell is introduced into a normal cell, the recipient cell 480. P 53 gene: (A) Destroys the DNA (A) A proto-oncogene (B) Loses its ability to divide (B) An oncogene (C) Dies (C) A tumour suppressor gene (D) Changes into a cancer cell (D) None of these 474. A normal cell can be transformed into a 481. Retinoblastoma can result from a muta- cancer cell by all of the following except tion in (A) Ionising radiation (A) ras proto-oncogene (B) Mutagenic chemicals (B) erbB proto-oncogene (C) Oncogenic bacteria (C) p 53 gene (D) Some viruses (D) RB 1 gene 475. Proto-oncogens are present in 482 All the following statements about retino (A) Oncoviruses blastoma are true except (B) Cancer cells (A) At least two mutations are required for its (C) Healthy human cells development (D) Prokaryotes (B) One mutation can be inherited from a parent 266 MCQs IN BIOCHEMISTRY

(C) Children who have inherited one mutation (B) Amplification of dihydrofolate reducatse gene develop retinoblastoma at a younger age (C) Mutation in the dihydrofolate reductase gene (D) RB 1 gene promotes the development of so that the enzyme is no longer inhibited by retinoblastoma amethopterin (D) Developing alternate pathway of thymidylate 483. Ames assay is a rapid method for detection synthesis of

(A) Oncoviruses 489. The major source of NH3 produced by the kidney is (B) Retroviuses (C) Chemical carcinogens (A) Leucine (B) Glycine (D) Typhoid (C) Alanine (D) Glutamine

484. Amplification of dihydrofolate reductase 490. Which of these methyl donors is not a gene in a cancer cell makes the cell quanternary ammonium compound? (A) Susceptible to folic acid deficiency (A) Methionine (B) Choline (B) Less malignant (C) Betain (D) Betainaldehyde (C) Resistant to amethopterin therapy 491. L-glutamic acid is subjected to oxidative (D) Responsive to amethopterin therapy deaminition by (A) L-amino acid dehydrogenase 485. Conversion of a procarcinogen into a carcinogen often requires (B) L-glutamate dehydrogenase (C) Glutaminase (A) (D) Glutamine synthetase (B) Microsomal hydroxylation (C) Exposure to ultraviolet radiation 492. A prokaryotic ribosome is made up of (D) Exposure to X-rays ______sub units. (A) 20 S and 50S (B) 30S and 50S 486. The only correct statement about onco- viruses is (C) 30S and 60S (D) 20S and 50S (A) All the oncoviruses are RNA viruses 493. AN Eukaryotic ribosome is made up of ______sub unit. (B) Reverse transcriptase is present in all oncoviruses (A) 40S and 60S (B) 40S and 50S (C) Viral oncogenes are identical to human (C) 40S and 80S (D) 60S and 80S protooncogens 494. GTP is not required for (D) Both DNA and RNA viruses can be (A) Capping L of mRNA oncoviruses (B) Fusion of 40S and 60S of ribosome 487. RB 1 gene is (C) Accommodation of tRNA amino acid (A) A tumour suppressor gene (D) Formation of tRNA amino acid complex (B) Oncogene 495. The antibiotic which inhibits DNA (C) Proto-oncogene dependent RNA polymerase is (D) Activated proto-oncogene (A) Mitomycin C (B) Actinomycin d (C) Streptomycin (D) Puromycin 488. Cancer cells may become resistant to amethopterin by 496. The antibiotic which cleaves DNA is (A) Developing mechanisms to destroy amethopterin (A) Actinomycin d (B) Streptomycin (C) Puromycin (D) Mitomycin C NUCLEIC ACIDS 267

497. The antibiotic which has a structure similar 506. Progressive transmethylation of ethano- to the amino acyl end of tRNA tyrosine is lamine gives (A) Actinomycin d (B) Streptomycin (A) Creatinine (C) Puromycin (D) Mitomycin c (B) Choline 498. ATP is required for (C) Methionine (D) N-methyl nicotinamide (A) Fusion of 40S and 60S of ribosome (B) Accommodation tRNA amino acid in a site of 507. Genetic information originates from ribosome (A) Cistron of DNA (C) Movement of ribosome along mRNA (B) Codons of mRNA (D) formation of tRNA amino acid complex (C) Anticodons of tRNA 499. What is the subcellular site for the bio- (D) Histones of nucleoproteins synthesis of proteins? 508. The genetic code operates through (A) Chromosomes (B) Lymosomes (A) The protein moiety of DNA (C) Ribosomes (D) Centrosomes (B) Cistrom of DNA 500. An animal is in negative nitrogen balance (C) Nucleotide sequence of m RNA when (D) The anticodons of tRNA (A) Intake exceeds output 509. DNA synthesis in laboratory was first (B) New tissue is being synthesized achieved by (C) Output exceeds intake (A) Watson and crick (B) Khorana (D) Intake is equal to output (C) A.Kornberg (D) Ochoa

501. When NH3 is perfused through a dog’s liver ______is formed, while ______is 510. Among the different types of RNA, which formed in the birds liver. one has the highest M.W.? (A) Urea, Uric acid (B) Urea, allantoin (A) mRNA (B) rRNA (C) Uric acid, creatinine (C) yeast RNA (D) tRNA (D) Uric acid, Urea 511. From DNA the genetic message is trans- 502. Aspartate amino transferase uses the cribed into this compound: following for transamination: (A) Protein (B) mRNA (A) Glutamic acid and pyruvic acid (C) tRNA (D) rRNA (B) Glutamic acid and oxaloacetic acid 512. This compound has a double helical (C) Aspartic acid and pyruvic acid structure. (D) aspartic acid and keto adipic acid (A) Deoxyribonucleic acid 503. Which among the following compounds is not a protein? (B) RNA (C) Flavine-adevine dinucleotide (A) Insulin (B) Hheparin (C) Mucin (D) Pepsin (D) Nicotinamide adamine dinucleotide 504. Almost all the urea is formed in this tissue: 513. The structural stability of the double helix of DNA is as cribbed largely to (A) Kidney (B) Urethra (C) Uterus (D) Liver (A) Hydrogen bonding between adjacent purine bases 505. A polyribosome will have about ______individual ribosomes. (B) Hydrophobic bonding between staked purine and pyrinuidine nuclei (A) 20 (B) 10 (C) 5 (D) 2 268 MCQs IN BIOCHEMISTRY

(C) Hydrogen bonding between adjacent 520. Which of the following contains a deoxy pyrimidine bases sugar? (E) Hydrogen bonding between purine and (A) RNA (B) DNA pyrimidine bases (C) ATP (D)UTP 514. Which of the following statements about 521. DNA is nucleic acid is most correct? (A) Usually present in tissues as a nucleo protein (A) Both pentose nucleic acid and deoxypentose and cannot be separated from its protein nucleic acid contain the same pyrimidines component (B) Both pentose nucleic acid and deoxypentose (B) A long chain polymer in which the nucleic acid and deoxypentose nucleic acid internucleotide linkages are of the diester type Contain the same purines between C-3’ and C-5’ (C) RNA contains cytosine and thymine (C) Different from RNA since in the latter the (D) DNA and RNA are hydrolysed by weak alkali internucleotide linkages are between C-2’ and C-5’ 515. Acid hydrolysis of ribonucleic acid would (D) Hydrolyzed by weal alkali (pH9 to 100°C) yield the following major products: 522. Nobody is the name given to (A) d- deoxyribose, cytosine, adenine (A) Ribosome (B) Microsome (B) d-ribose, thymine, Guanine (C) Centrosome (D) Nucleosome (C) d-ribose, cytosine, uracil, thymine (D) d-ribose, uracil, adenine, guanine, cytosine 523. Transcription is the formation of 516. RNA does not contain (A) DNA from a parent DNA (B) mRNA from a parent mRNA (A) adenine (B) OH methyl cytosine (C) pre mRNA from DNA (C) d-ribose (D) Uracil (D) protein through mRNA 517. Which of the following statements is 524. Translation is the formation of correct? (A) DNA from DNA (A) a nucleo protein usually contain deoxy sugars of the hexose type (B) mRNA from DNA (B) Nucleoproteins are usually absent from the (C) Protein through mRNA cytoplasm (D) mRNA from pre mRNA (C) Nucleoproteins usually are present in the 525. Sigma and Rho factors are required for nucleus only (A) Replication (B) Transcription (D) Nucleoproteins usually occur in the nucleus and cytoplasm (C) Translation (D) Polymerisation 518. Whcih of the following compound is 526. The genine of φφφ×174 bacteriophage is present in RNA but absent from DNA? interesting in that if contains (A) Thymine (B) Cytosine (A) No DNA (C) Uracil (D) Guanine (B) DNA with uracil (C) Single stranded DNA 519. Nucleic acids can be detected by means of their absorption maxima near 260 nm. (D) Triple standard DNA Their absorption in this range is due to 527. Okasaki fragments are small bits of (A) Proteins (A) RNA (B) Purines and pyrimidines (B) DNA (C) Ribose (C) DNA with RNA heads (D) Deoxyribose (D) RNA with DNA heads NUCLEIC ACIDS 269

528. In addition to the DNA of nucleus there Q536. RNA synthesis requires DNA is (A) RNA primer (B) RNA template (A) Mitochondrian (C) DNA template (D) DNA primer (B) Endoplasmic reticulum (C) Golgi apparatus 537. The mRNA ready for protein synthesis has (D) Plasma membrane the ______cap. (A) ATP (B) CTP 529. The mitochondrial DNA is (C) GTP (D)UTP (A) Like the nuclear DNA in structure (B) Single stranded, linear 538. mRNA ready for protein synthesis has the (C) Double stranded, circular poly ______toil. (D) Single stranded, circular (A) G (B) A 530. A synthetic RNA having the sequence of (C) U (D)C UUUUUU (Poly U) will give a protein 539. The codon for phenyl Alanine is having poly ______. (A) Alamine (B) Phenyl alanine (A) AAA (B) CCC (C) Glycine (D) Methionine (C) GGG (D) UUU 531. Lac operon of E. coli contains ______is 540. Blue print for genetic information residues continuity. in (A) Regulator and operator genes only (A) mRNA (B) tRNA (B) Operator and structural genes only (C) rRNA (D)DNA (C) Regular and structural genes only 541. Genes are (D) Regulator, operator and structural genes (A) RNA (B) DNA 532. A mRNA of eukaryotes can code for (C) lipoproteins and (D) Chromoproteins (A) Only one polypeptide (B) Two polypeptides 542. Codons are in (C) Three polypeptides (A)DNA (B) mRNA (D) Five polypeptides (C) tRNA (D) rRNA

533. mRNA of prokaryotes can code for 543. The genetic code operates via (A) More than one polypeptide (A) The protein moiety of DNA (B) Only one polypeptide (B) The base sequences of DNA (C) Many exons and introns (C) The nucleotide sequence of mRNA (D) Introns only (D) The base sequence of tRNA 534. DNA directed RNA polymerase is 544. Urine bases with methyl substituents (A) Replicase occurring in plants are (B) Transcriptase (A) Caffeine (B) Theophylline (C) Reverse transcriptase (C) Theobromine (D) All of these (D) Polymerase III 535. RNA directed DNA polymerase is 545. Genetic information in human beings is stored in (A) Replicase (B) Transcriptase (A) DNA (B) RNA (C) Reversetranscriptase (C) Both (A) and (B) (D) None of these (D) Polymerase–III 270 MCQs IN BIOCHEMISTRY

546. All following are naturally occurring (A) Deoxyribose (B) Uracil nucleotides except (C) Adenine (D) Thymine (A) Cyclic AMP 555. Which of the following are nucleo proteins? (B) ATP (A) Protamines (C) DNA (B) Histones (D) Inosine monophosphate (C) Deoxy and Ribo nucleo proteins 547. If the amino group and a carboxylic (D) All of these group of the amino acid are attached to same carbon atom, the amino acid is 556. The total RNA in cell tRNA constitutes called as (A) 1–10% (B) 10–20% (A) Alpha (B) Beta (C) 30–50% (D) 50–80% (C) Gamma (D) Epsilon 557. Unit of genetic information: 548. If in a nucleic acid there are more than (A) DNA (B) RNA 8000 nucleotides it is most likely (C) Cistron (D) None of these (A) RNA (B) DNA 558. Anticodon sequence are seen in (C) Both (A) and (B) (D) None of these (A) tRNA and transcribed DNA strand 549. Genetic information in human beings is (B) tRNA and complementary DNA strand stored in (C) mRNA (A) RNA (B) DNA (D) mRNA and complementary DNA strand (C) Both (A) and (B) (D) mRNA 559. cAMD is destroyed by 550. In RNA, apart from ribose and phosphate, (A) Adenylate cyclase all following are present except (B) Phosphodiesterase (A) Adenine (B) Guanine (C) Synthetase phosphatase (C) Thymine (D) Cytosine (D) Synthetase kinase 551. Which of the following gives a positive 560. Restriction enzymes have been found in Ninhydrin test? (A) Humans (B) Birds (A) Reducing sugar (B) Triglycerides (C) Bacteria (D) Bacteriophase (C) α-amino acids (D) Phospholipids 561. Sulphur is not present in 552. A Gene is (A) Thiamine (B) Lipic acid (A) A single protein molecule (C) Thymine (D) Biotin (B) A group of chromosomes 562. Which one of the following binds to (C) An instruction for making a protein molecule specific nucleotide sequences? (D) A bit of DNA molecule (A) RNA polymerase (B) Repressor 553. In DNA, genetic information is located in (C) Inducer (D) Restriction (A) Purine bases 563. Using written convertion which one of the following sequences is complimentary to (B) Pyrimidine bases TGGCAGCCT? (C) Purine and pyrimidine bases (A) ACC GTC GGA (B) ACC GUC GGA (D) sugar (C) AGG CTG CCA (D) TGG CTC GGA 554. Which one of the following is not a 564. Ribosomes similar to those of bacterial constituent of RNA? found in NUCLEIC ACIDS 271

(A) Plant nucei (A) Ribose 5 phosphate (B) Cardiac muscle cytoplasm (B) Phosphoribosyl pyrophosphate (C) Liver endoplasmic reticulum (C) Hypoxanthine (D) Neuronal cytoplasm (D) Adenosine 565 The mechanism of synthesis of DNA and 572. Carbon 6-of purine skeleton comes from RNA are similar in all the following ways (A) Atmospheric CO except 2 (B) 1 carbon carried by folate (A) They involve release of pyrophosphate from (C) Betoine each nucleotide added (D) Methionine (B) They require activated nucleotide precursor and Mg2+ 573. Uric acid is the catabolic end product of (C) The direction of synthesis is 5’ → 3’ (A) Porphyrine (B) Purines (D) They require a primer (C) Pyrimidines (D) Pyridoxine 566. Template-directed DNA synthesis occurs in 574. Diphenylamine method is employed in the all the following except quantitation of (A) The replication fork (A) Nucleic acid (B) RNA (B) Polymerase chain reaction (C)DNA (D) Proteins (C) Growth of RNA tumor viruses 575. Orcinol method is employed in the quanti- (D) Expression of oneogenes tation of 567. Which one of the following statements (A) Nucleic acid (B) DNA correctly describes eukaryotic DNA? (C) RNA (D) Proteins (A) They involve release of pyrophosphate from 576. Nucleic acid show strong absorption at each nucleotide precussor and Mg2+ one of the wavelength: (B) The direction of synthesis is (A) 280 nm (B) 220 nm (C) They require a primer 5’ → 3’ (C) 360 nm (D) 260 nm (D) None of these 577. tRNA has 568. Which one of the following causes frame shift mutation? (A) Clover leaf structure (B) anticodon arm (A) Transition (C) poly ‘A’ tay 3’ (B) Transversion (D) Cap at 5’ end (C) Deletion (D) Substitution of purine to pyrimidine 578. Which one of the following contributes nitrogen atoms to both purine and 569. Catabolism of thymidylate gives pyrimidine rings? (A) α-alanine (A) Aspartate (B) β-alanine (B) Carbanoyl phosphate (C) α-aminoisobutyrate (C) Carbondioxide (D) β-aminoisobutyrate (D) Tetrahydrofolate 570. Glycine gives ______atoms of purine. 579. The four nitrogen atoms of purines are derived from (A) C2, C3 (B) C4, C5 and N7

(C) C4, C5 and N9 (D) C4, C6 and N7 (A) Urea and NH3 (B) NH , Glycine and Glutamate 571. A common substrate of HGPRTase, APRTase 3 and PRPP glutamyl amidotransferase is (C) NH3, Asparate and Glutamate (D) Aspartate, Glutamine and Glycine 272 MCQs IN BIOCHEMISTRY

580. A drug which prevents uric acid synthesis (A) Glutamine and Carbamoyl-p by inhibiting the enzyme Xanthine oxi- (B) Asparate and Carbamoyl-p dase is (C) Glutamate and NH3

(A) Aspirin (B) Allopurinal (D) Glutamine and NH3 (C) Colchicine (D) Phenyl benzoate 589. All are true about lesch-nyhan syndrome 581. Glycine contributes to the following C and except N of purine nucleus: (A) Produces self-mutilation

(A) C1, C2 and N7 (B) C8, C8 and N9 (B) Genetic deficiency of the enzyme

(C) C4, C5 and N7 (D) C4, C5 and N9 (C) Elevated levels of uric acid in blood (D) Inheritance is autosomal recessive 582. Insoinic acid is the biological precursor of (A) Cytosine and Uric acid 590. Synthesis of GMP and IMP requires the following: (B) Adenylve acid and Glucine floc acid (A) NH NAD+, ATP (C) Orotic acid and Uridylic acid 3 (B) Glutamine, NAD+, ATP (D) Adenosine acid Thymidine + (C) NH3, GTP, NADP 583. The probable metabolic defect in gents is (D) Glutamine, GTP, NADP+ (A) A defect in excretion of uric acid by kidney 591. Which pathway is correct for catabolism (B) An overproduction of pyrimidines of purines to form uric acid? (C) An overproduction of uric acid (A) Guanylate→Adenylate→Xanthine→hypo- (D) Rise in calcium leading to deposition of calcium xanthine→Uric acid urate (B) Guanylate→inosinate→Xanthine→hypo- 584. In humans, the principal break down xanthine→Uric acid product of purines is (C) Adenylate→Inosinate→Xanthine hypo- xanthine Uric acid (A) NH3 (B) Allantin → (C) Alanine (D) Uric acid (D) Adenylate→Inosinate→hypoxanthine Xanthine→Uric acid 585. A key substance in the committed step of pyrimidines biosynthesis is 592. Polysemes do not contain (A) Ribose-5-phosphate (A) Protein (B) DNA (B) Carbamoyl phosphate (C) mRNA (D) rRNA (C) ATP (D) Glutamine 593. The formation of a peptide bond during the elongation step of protein synthesis 586. In humans, the principal metabolic results in the splitting of how many high product of pyrimidines is energy bonds? (A) Uric acid (B) Allantoin (A) 1 (B) 2 (C) Hypoxanthine (D) β-alanine (C) 3 (D) 4 587. In most mammals, except primates, uric acid is metabolized by 594. Translocase is an enzyme required in the process of (A) Oxidation to allantoin (A) DNA replication (B) Reduction to NH3 (C) Hydrolysis to allantoin (B) RNA synthesis (C) Initiation of protein synthesis (D) Hydrolysis to NH3 (D) Elongation of peptides 588. Two nitrogen of the pyrimidines ring are obtained from 595. Nonsense codons bring about NUCLEIC ACIDS 273

(A) Amino acid activation (D) Multiple codons for a single amino acid (B) Initiation of protein synthesis 603. The normal function of restriction endonuc- (C) Termination of protein synthesis leases is to (D) Elongation of polypeptide chains (A) Excise introns from hrRNA 596. Which of the following genes of the E.coli (B) Polymerize nucleotides to form RNA “Lac operon” codes for a constitutive (C) Remove primer from okazaki fragments protein? (D) Protect bacteria from foreign DNA (A) The ‘a’ gene (B) The ‘i’ gene (C) The ‘c’ gene (D) The ‘z’ gene 604. In contrast to Eukaryotic mRNA, pro- karyotic mRNA is characterized by 597. In the process of transcription, the flow (A) Having 7-methyl guanosine triphosphate at of genetic information is from the 5’ end (A) DNA to DNA (B) DNA to protein (B) Being polycystronic (C) RNA to protein (D) DNA to RNA (C) Being only monocystronic 598. The anticodon region is an important part (D) Being synthesized with introns of the structure of 605. DNA ligase of E. coli requires which of the (A) rRNA (B) tRNA following co-factors? (C) mRNA (D) hrRNA (A) FAD (B) NAD+ 599. The region of the Lac operon which must (C) NADP+ (D) NADH be free from structural gene transcription to occur is 606. Which of the following is transcribed during repression? (A) The operator locus (B) The promoter site (A) Structural gene (B) Promoter gene (C) The ‘a’ gene (C) Regulator gene (D) Operator gene (D) The ‘i’ gene 607. mRNA is complementary copy of 600. Another name for reverse transcriptase is (A) 5′-3′ strand of DNA+ (A) DNA dependent DNA polymerase (B) 3′-5′ strand of DNA (C) Antisense strand of DNA (B) DNA dependent RNA polymerase (D) tRNA (C) RNA dependent DNA polymerase (D) RNA dependent RNA polymerase 608. Synthesis of RNA molecule is terminated by a signal which is recognised by 601. In the ’lac operon’ concept, which of the (A) α-factor (B) β-factor following is a protein? (C) δ-factor (D) ρ (A) Operator (B) Repressor 609. The binding of prokaryotic DNA depen- (C) Inducer (D) Vector dent RNA polymerase to promoter sits of 602. Degeneracy of the genetic code denotes genes is inhibited by the antibiotic: the existence of (A) Streptomycin (B) Rifamcin (A) Base triplets that do not code for any amino (C) Aueromycin (D) Puromycin acids 610. In E. coli the chain initiating amino acid in (B) Codons consisting of only two bases protein synthesis is (C) Codons that include one or more of the (A) N-formyl methionine(B) Methionine unusual bases (C) Serine (D) Cysteine 274 MCQs IN BIOCHEMISTRY

611. Amanitin the mushroom poison inhibits upstream and most distant from the start (A) Glycoprotein synthesis site? (B) ATP synthesis (A) RNA polymerase (B) Repressor (C) DNA synthesis (C) Inducer (D) Restriction (D) mRNA synthesis 618. Using written convention which one of the 612. How many high-energy phosphate bond following sequences is complimentary to equivalents are required for amino acid TGGCAGCCT? activation in protein synthesis? (A) ACCGTCGGA (B) ACCGUCGGA (A) One (B) Two (C) AGGCTGCCA (D) TGGCTCGGA (C) Three (D) Four 619. Ribosomes similar to those of bacteria 613. Translation results in the formation of found in (A) mRNA (B) tRNA (A) Plant nuclei (C) rRNA (D) A protein molecule (B) Cardiac muscle cytoplasm (C) Liver endoplasmic reticulum 614. Elongation of a peptide chain involves all the following except (D) Neuronal cytoplasm (A) mRNA (B)GTP 620. The mechanism of synthesis of DNA and (C) Formyl-Met-tRNA (D) Tu, TS and G factors RNA are similar to all the following ways except 615. The ‘rho’ (ρρρ) factor is involved (A) They involve release of pyrophosphate from (A) To increase the rate of RNA synthesis each nucleotide added (B) In binding catabolite repressor to the promoter (B) They require activated nucleotide precursor region and Mg2+ (C) In proper termination of transcription (C) The direction of synthesis is (D) To allow proper initiation of transcriptide (D) They require a primer 616. In the biosynthesis of c-DNA, the joining 621. Template-directed DNA synthesis occurs in enzyme ligase requires all the following except (A) GTP (B) ATP (A) The replication fork (C) CTP (D)UTP (B) Polymerase chain reaction 617. Which one of the following binds to (C) Growth of RNA tumor viruses specific nucleotide sequences that are (D) Expression of oncogenes NUCLEIC ACIDS 275

ANSWERS 1. B 2. B 3. A 4. C 5. A 6. C 7. B 8. D 9. C 10. D 11. A 12. A 13. A 14. D 15. B 16. A 17. C 18. C 19. A 20. A 21. B 22. C 23. C 24. D 25. C 26. A 27. C 28. B 29. C 30. A 31. D 32. A 33. B 34. A 35. A 36. C 37. C 38. A 39. B 40. D 41. C 42. C 43. B 44. C 45. D 46. B 47. A 48. C 49. B 50. A 51. D 52. B 53. B 54. D 55. D 56. A 57. D 58. A 59. A 60. D 61. B 62. C 63. A 64. A 65. A 66. A 67. A 68. A 69. B 70. A 71. A 72. A 73. C 74. B 75. C 76. A 77. C 78. D 79. B 80. A 81. C 82. A 83. A 84. A 85. A 86. D 87. A 88. B 89. A 90. C 91. B 92. B 93. A 94. A 95. A 96. A 97. B 98. B 99. D 100. A 101. B 102. A 103. B 104. B 105. A 106. B 107. C 108. A 109. D 110. C 111. D 112. A 113. B 114. A 115. B 116. A 117. D 118. A 119. A 120. C 121. A 122. D 123. B 124. C 125. A 126. A 127. D 128. C 129. A 130. A 131. B 132. B 133. D 134. A 135. A 136. D 137. B 138. B 139. A 140. D 141. B 142. D 143. C 144. B 145. D 146. B 147. B 148. B 149. D 150. D 151. D 152. A 153. C 154. A 155. B 156. C 157. B 158. A 159. A 160. A 161. C 162. C 163. C 164. C 165. D 166. C 167. A 168. C 169. C 170. D 171. B 172. B 173. C 174. D 175. D 176. A 177. B 178. D 179. D 180. C 181. B 182. B 183. C 184. B 185. A 186. D 187. B 188. C 189. D 190. A 191. B 192. C 193. A 194. D 195. D 196. A 197. D 198. C 199. A 200. C 201. D 202. C 203. B 204. D 205. C 206. D 207. B 208. C 209. C 210. D 211. B 212. C 213. D 214. C 215. B 216. B 217. D 218. B 219. D 220. A 221. A 222. D 223. A 224. C 225. A 226. B 227. C 228. C 229. D 230. B 231. C 232. A 233. C 234. A 235. B 236. A 237. C 238. C 239. D 240. D 241. B 242. C 243. D 244. C 245. C 246. B 247. A 248. C 249. A 250. D 251. A 252. C 276 MCQs IN BIOCHEMISTRY

253. D 254. D 255. C 256. C 257. C 258. D 259. D 260. A 261. B 262. B 263. A 264. A 265. C 266. D 267. B 268. C 269. B 270. D 271. C 272. B 273. A 274. C 275. A 276. C 277. A 278. B 279. C 280. C 281. D 282. D 283. C 284. D 285. C 286. B 287. A 288. A 289. D 290. B 291. B 292. C 293. B 294. A 295. C 296. A 297. D 298. C 299. C 300. D 301. B 302. C 303. B 304. A 305. C 306. D 307. D 308. B 309. B 310. C 311. A 312. C 313. A 314. B 315. B 316. A 317. A 318. D 319. D 320. A 321. C 322. C 323. C 324. C 325. A 326. D 327. A 328. B 329. C 330. D 331. C 332. B 333. A 334. D 335. D 336. C 337. A 338. C 339. C 340. C 341. C 342. D 343. A 344. A 345. B 346. D 347. C 348. B 349. B 350. D 351. A 352. B 353. D 354. C 355. A 356. B 357. D 358. A 359. D 360. B 361. B 362. A 363. A 364. C 365. C 366. C 367. D 368. D 369. B 370. B 371. B 372. C 373. B 374. D 375. C 376. B 377. B 378. D 379. D 380. B 381. D 382. D 383. D 384. C 385. B 386. B 387. C 388. D 389. C 390. D 391. C 392. D 393. A 394. C 395. D 396. A 397. B 398. B 399. C 400. A 401. D 402. B 403. D 404. A 405. D 406. C 407. D 408. C 409. D 410. A 411. C 412. B 413. A 414. C 415. D 416. B 417. C 418. A 419. D 420. C 421. C 422. D 423. D 424. D 425. C 426. C 427. C 428. C 429. D 430. C 431. B 432. C 433. D 434. C 435. C 436. B 437. D 438. C 439. B 440. C 441. C 442. A 443. C 444. C 445. D 446. D 447. D 448. C 449. A 450. D 451. D 452. B 453. D 454. D 455. B 456. C 457. A 458. D 459. B 460. A 461. C 462. D 463. C 464. B 465. A 466. C 467. B 468. D 469. A 470. A 471. B 472. D 473. D 474. C 475. C 476. D 477.A 478. A 479. C 480. C 481. D 482. D 483. C 484. C 485. B 486. D 487. A 488. B 489. D 490. A 491. B 492. B 493. A 494. D 495. B 496. D 497. C 498. D 499. C 500. C 501. A 502. B 503. D 504. D 505. C 506. C 507. A 508. C 509. C 510. B NUCLEIC ACIDS 277

511. B 512. A 513. D 514. B 515. D 516. B 517. D 518. C 519. B 520. B 521. B 522. C 523. C 524. B 525. C 526. C 527. C 528. A 529. C 530. B 531. D 532. A 533. A 534. B 535. C 536. C 537. C 538. B 539. D 540. D 541. B 542. B 543. C 544. D 545. A 546. C 547. A 548. B 549. B 550. C 551. C 552. D 553. C 554. A 555. D 556. B 557. C 558. A 559. B 560. C 561. C 562. A 563. A 564. A 565. A 566. C 567. C 568. C 569. D 570. B 571. B 572. A 573. A 574. C 575. C 576. D 577. A 578. A 579. D 580. B 581. C 582. B 583. C 584. D 585. B 586. D 587. A 588. B 589. B 590. B 591. D 592. B 593. B 594. D 595. C 596. B 597. D 598. B 599. A 600. C 601. B 602. B 603. D 604. A 605. B 606. C 607. B 608. D 609. B 610. A 611. D 612. B 613. D 614. C 615. C 616. B 617. A 618. A 619. A 620. D 621. C This page intentionally left blank CHAPTER 10

WWWAAATERTERTER &&& EEELECTROLLECTROLLECTROLYTEYTEYTE BBBALANCEALANCEALANCE

1. The total body water in various subjects 7. The fluid present in bones which can not is relatively constant when expressed as be exchanged readily because of relative percentage of the lean body mass and is avascularity is about about (A) 20 ml/kg (B) 25 ml/kg (A). 30% (B) 40% (C) 45 ml/kg (D) 60 ml/kg (C) 50% (D) 70% 2.. The percentage of water contained in the 8. Water derived in gm from complete body of an individual is less because of oxidation of each gm of carbohydrate is about (A) High fat content (B) Low fat content (C) High protein content(D) Low protein content (A) 0.15 (B) 0.25 (C) 0.35 (D) 0.55 3. In intracellular compartment the fluid present in ml/kg body weight is about 9. The oxidation of 100 gm of fat yields (A) 100 (B) 200 (A) 50 gm water (B) 107 gm water (C) 200 (D) 330 (C) 150 gm water (D) 200 gm water 4. In extra cellular compartment, the fluid 10. Each gm of protein on complete oxidation present in ml/kg of body weight is about yields (A) 120 (B) 220 (C) 270 (D) 330 (A) 0.21 gm water (B) 0.31 gm water (C) 0.41 gm water (D) 0.51 gm water 5. Fluid present in dense connective tissue and cartilage in ml/kg body weight is 11. The daily total body water derived from about oxidation of food stuffs is about (A) 10 (B) 20 (A) 100 ml (B) 300 ml (C) 45 (D) 55 (C) 600 ml (D) 1000 ml 6. The total body water in ml/kg body 12. The daily water allowance for normal weight in average normal young adult male is about infant is about (A) 200 (B) 400 (A) 100–200 ml (B) 250–300 ml (C) 600 (D) 1000 (C) 330–1000 ml (D) 1000–2000 ml 280 MCQs IN BIOCHEMISTRY

13. The daily water allowance for normal 22. Minimum excretory urinary volume for adult (60 kg) is about waste products elimination during 24 hrs (A) 200–600 ml (B) 500–800 ml is (C) 800–1500 ml (D) 1800–2500 ml (A) 200–300 ml (B) 200–400 ml (C) 500–600 ml (D) 800 ml 14. Insensible loss of body water of normal adult is about 23. In primary dehydration (A) 50–100 ml (B) 100–200 ml (A) Intracellular fluid volume is reduced (C) 300–500 ml (D) 600–1000 ml (B) Intracellular fluid volume remains normal (C) Extracellular fluid volume is much reduced 15. The predominant cation of plasma is (D) Extracellular fluid volume is much increased (A) Na+ (B) K+ (C) Ca+ (D) Mg++ 24. An important cause of secondary dehy- dration is 16. The predominant action of plasma is (A) Dysphagia (A) HCO – (B) Cl– 3 (B) Oesophageal varices (C) HPO – – (D) SO – – 4 4 (C) Oesophageal varices 17. Vasopressin (ADH) (D) Gastroenteritis (A) Enhance facultative reabsorption of water 25. Important finding of secondary dehydra- (B) Decreases reabsorption of water tion is (C) Increases excretion of calcium (A) Intracellular oedema (D) Decreases excretion of calcium (B) Cellular dehydration 18. Enhanced facultative reabsorption of (C) Thirst water by Vasopressin is mediated by (D) Muscle cramps ++ (A) Cyclic AMP (B) Ca 26. Urine examination in secondary dehy- (C) Cyclic GMP (D) Mg++ dration shows 19. Action of kinins is to (A) Ketonuria (A) Increase salt excretion (B) Low specific gravity (B) Decrease salt retention (C) High specific gravity (C) Decrease water retention (D) Albuminuria (D) Increase both salt and water excretion 27. The total calcium of the human body is about 20. The activity of kinins is modulated by (A) 100–150 g (B) 200–300 g (A) Prostaglandins (C) 1–1.5 kg (D) 2–3 kg (B) Ca++ (C) Increased cAMP level 28. Daily requirement of calcium for normal (D) Increased cGMP level adult human is (A) 100 mg (B) 800 mg 21. An important cause of water intoxication is (C) 2 g (D) 4 g (A) Nephrogenic diabetes insipidus 29. Normal total serum calcium level varies (B) Renal failure between (C) Gastroenteritis (A) 4–5 mg (B) 9–11 mg (D) Fanconi syndrome (C) 15–20 mg (D) 50–100 mg WATER AND ELECTROLYTE BALANCE 281

30. The element needed in quantities greater 39. In serum product of Ca x p (in mg/100ml) than 100 mg for human beings is in children is normally (A) Calcium (B) Zinc (A) 20 (B) 30 (C) Selenium (D) Cobalt (C) 50 (D) 60 31. The mineral present in the human body 40. In ricket, the product of Ca x p (in mg/ in larger amounts than any other cation 100 ml) in serum is below is (A) 30 (B) 50 (A) Sodium (B) Calcium (C) 70 (D) 100 (C) Potassium (D) Iron 41. In man, the amount of calcium in gms 32. The percentage of the total body calcium filtered in 24 hrs period by the renal present in bones is glomeruli is (A) 1 (B) 11 (A) 5 (B) 10 (C) 55 (D) 99 (C) 15 (D) 20 33. The percentage of calcium present in 42. The percentage of the calcium eliminated extracellular fluid is in feces is (A) 1 (B) 5 (A) 10–20 (B) 30–40 (C) 10 (D) 50 (C) 50–60 (D) 70–90 34. The physiologically active form of calcium 43. The maximal renal tubular reabsorptive is capacity for calcium (Tmca) in mg/min is about (A) Protein bond (B) Ionised (A) 1.5 ± 0.1 (B) 4.99 ± 0.21 (C) Complexed with citrate (C) 5.5 ± 1.2 (D) 10.2 ± 2.2 (D) Complexed with carbonate 44. Renal ricket is caused by renal tubular 35. The normal concentration of calcium in defect (usually inherited) which interferes C.S.F is with reabsorption of (A) 1.5–2.5 mg/100 ml (A) Calcium (B) Phosphorous (B) 2.5–4 mg/100 ml (C) Sodium (D) Chloride (C) 4.5–5 mg/100 ml 45. After operative removal of the parathy- (D) 9–10 mg/100 ml roid glands resulting into hypoparathy- roidism the concentration of the serum 36. Absorption of calcium is increased on a calcium may drop below (A) High protein diet (B) Low protein diet (A) 11 mg (B) 10 mg (C) High fat diet (D) Low fat diet (C) 9 mg (D) 7 mg 37. Calcium absorption is interfered by 46. One of the principal cations of soft tissue (A) Protein in diet and body fluids is (B) Phytic acid in cereals (A) Mg (B) S (C) Alkaline intestinal pH (C) Mn (D) Co (D) Vitamin D 47. The normal concentration of magnesium 38. Calcium absorption is increased by in whole blood is (A) Vitamin D (B) Vitamin C (A) 0–1 mg/100 ml (B) 1–2 mg/100 ml (C) Vitamin K (D) Vitamin E (C) 2–4 mg/100 ml (D) 4–8 mg/100 ml 282 MCQs IN BIOCHEMISTRY

48. The normal concentration of magnesium 57. Hypernatremia may occur in in C.S.F is about (A) Diabetes insipidus (A) 1 mg/100 ml (B) 3 mg/100 ml (B) Diuretic medication (C) 5 mg/100 ml (D) 8 mg/100 ml (C) Heavy sweating 49. The magnesium content of muscle is about (D) Kidney disease (A) 5 mg/100 ml (B) 10 mg/100 ml 58. The metabolism of sodium is regulated by (C) 21 mg/100 ml (D) 50 mg/100 ml the hormone:

50. Intestinal absorption of magnesium is (A) Insulin (B) Aldosterone increased in (C) PTH (D) Somatostatin (A) Calcium deficient diet 59. The principal cation in intracellular fluid (B) High calcium diet is (C) High oxalate diet (A) Sodium (B) Potassium (D) High phytate diet (C) Calcium (D) Magnesium

51. Deficiency of magnesium may occur with 60. The normal concentration of potassium in (A) Alcoholism whole blood is (B) Diabetes mellitus (A) 50 mg/100 ml (B) 100 mg/100 ml (C) Hypothyroidism (C) 150 mg/100 ml (D) 200 mg/100 ml (D) Advanced renal failure 61. The normal concentration of potassium in 52. Hypermagnesemia may be observed in human plasma in meq/I is about (A) Hyperparathyroidism (A) 1 (B) 2 (B) Diabetes mellitus (C) 3 (D) 5

(C) Kwashiorkar 62. The normal concentration of potassium in (D) Primary aldosteronism cells in ng/100 ml is about 53. Na+/K+-ATPase along with ATP requires (A) 100 (B) 200 (A) Ca (B) Mn (C) 350 (D) 440 (C) Mg (D) Cl 63. Potassium content of nerve tissue in mg/ 54. The principal cation in extracellular fluid 100 ml is about is (A) 200 (B) 330 (A) Sodium (B) Potassium (C) 400 (D) 530 (C) Calcium (D) Magnesium 64. Potassium content of muscle tissue in 55. The normal concentration of sodium (in mg/100 ml is about mg/100 ml) of human plasma is (A) 50–100 (B) 100–150 (A) 100 (B) 200 (C) 250–400 (D) 150–200 (C) 250 (D) 330 65. One of the symptoms of low serum 56. A decrease in serum sodium may occur in potassium concentration includes (A) Adrenocortical insufficiency (A) Muscle weakness (B) Hypoparathyroidism (B) Confusion (C) Hyperparathyroidism (C) Numbness (D) Thyrotoxicosis (D) Tingling of extremities WATER AND ELECTROLYTE BALANCE 283

66. Potassium metabolism is regulated by the 75. The exclusive function of iron in the body hormone: is confined to the process of (A) Aldosterone (B) PTH (A) Muscular contraction (C) Somatostatin (D) Estrogen (B) Nerve excitation 67. A high serum potassium, accompanied by (C) Cellular respiration a high intracellular potassium occurs in (D) Blood coagulation

(A) Adrenal insufficiency 76. The normal pH of the blood is (B) Any illness (A) 7.0 (B) 7.1 (C) Gastrointestinal losses (C) 7.2 (D) 7.4 (D) Cushing’s syndrome 77. The normal concentration of bicarbonate 68. Hypokalemia occurs in in blood is (A) Cushing’s syndrome (A) 21 meq/L (B) 24 meq/L (B) Addison’s disease (C) 26 meq/L (D) 30 meq/L (C) Renal failure (D) Advanced dehydration 78. At the pH of blood 7.4, the ratio between the carbonic acid and bicarbonate 69. Cardiac arrest may occur due to over fractions is doses of (A) 1 : 10 (B) 1 : 20 (A) Sodium (B) Potassium (C) 1 : 30 (D) 1 : 40 (C) Zinc (D) Magnesium 79. A 0.22 M solution of lactic acid (pK 3.9) 70. The normal concentration of chloride in a was found to contain 0.20 M in the disso- mg/100 ml of whole blood is about ciated form and 0.02 M undissociated (A) 200 (B) 250 form, the pH of the solution is (C) 400 (D) 450 (A) 2.9 (B) 3.3 71. The normal concentration of chloride in (C) 4.9 (D) 5.4 mg/100 ml of plasma is about 80. Important buffer system of extracellular (A) 100 (B) 200 fluid is (C) 365 (D) 450 (A) Bicarbonate/carbonic acid 72. The normal concentration of chlorine in (B) Disodium hydrogen phosphate/sodium mg/100 ml of C.S.F is about dihydrogen phosphate (A) 200 (B) 250 (C) Plasma proteins (C) 300 (D) 440 (D) Organic Phosphate 73. Hypokalemia with an accompanying 81. The pH of body fluids is stabilized by hypochloremic alkalosis may be observed buffer systems. The compound which will in be the most effective buffer at physiologic (A) Cushing’s syndrome(B) Addison’s disease pH is (C) Hyptothyroidism (D) Malnutrition (A) Na2HPO4 pKa = 12.32

74. Hypercholremia is associated with (B) Na2HPO4 pKa=7.21

(A) Hyponatremia (B) Hypernatremia (C) NH4OH pKa = 7.24

(C) Metabolic alkalosis (D) Respiratory acidosis (D) Citric acid pKa = 3.09 284 MCQs IN BIOCHEMISTRY

82. The percentage of CO2 carrying capacity 90. Of the total body water, intracellular of whole blood by hemoglobin and compartment contains about oxyhemoglobin is (A) 50% (B) 60% (A) 20 (B) 40 (C) 70% (D) 80% (C) 60 (D) 80 91. Osmotically active substances in plasma 83. The normal serum CO content is 2 are (A) 18–20 meq/L (B) 24–29 meq/L (A) Sodium (B) Chloride (C) 30–34 meq/L (D) 35–38 meq/L (C) Proteins (D) All of these 84. The carbondioxide carrying power of the blood residing within the red cells is 92. Osmotic pressure of plasma is (A) 50% (B) 60% (A) 80–100 milliosmole/litre (C) 85% (D) 100% (B) 180–200 milliosmole/litre (C) 280–300 milliosmole/litre 85. Within the red blood cells the buffering capacity contributed by the phosphates (D) 380–400 milliosmole/litre is 93. Contribution of albumin to colloid osmotic (A) 5% (B) 10% pressure of plasma is about (C) 20% (D) 25% (A) 10% (B) 50% 86. The normal ratio between the alkaline (C) 80% (D) 90% phosphate and acid phosphate in plasma is 94. The highest concentration of proteins is present in (A) 2 : 1 (B) 1 : 4 (A) Plasma (B) Interstitial fluid (C) 20 : 1 (D) 4 : 1 (C) Interstitial fluid (D) Transcellular fluid 87. The oxygen dissociation curve for hemoglobin is shifted to the right by 95. Oncotic pressure of plasma is due to

(A) Decreased O2 tension (A) Proteins (B) Chloride

(B) Decreased CO2 tension (C) Sodium (D) All of these (C) Increased CO tension 2 96. Oncotic pressure of plasma is about (D) Increased pH (A) 10 mm of Hg (B) 15 mm of Hg 88. Bohr effect is (C) 25 mm of Hg (D) 50 mm of Hg (A) Shifting of oxyhemoglobin dissociation curve to the right 97. Oedema can occur when (B) Shifting of oxyhemoglobin dissociation curve (A) Plasma Na and Cl are decreased to the left (B) Plasma Na and Cl are increased (C) Ability of hemoglobin to combine with O2 (C) Plasma proteins are decreased (D) Exchange of chloride with carbonate (D) Plasma proteins are increased 89. Chloride shift is 98. Colloid osmotic pressure of intracellular (A) H ions leaving the RBC in exchange of Cl- fluid is (B) Cl– leaving the RBC in exchange of bicarbonate (A) Equal to that of plasma (C) Bicarbonate ion returns to plasma and (B) More than that of plasma exchanged with chloride which shifts into the cell (C) More than that of plasma (D) Carbonic acid to the plasma (D) Nearly zero WATER AND ELECTROLYTE BALANCE 285

99. The water produced during metabolic 107. Furosemide inhibits reabsorption of reactions in an adult is about sodium and chloride in (A) 100 ml/day (B) 300 ml/day (A) Proximal convoluted tubules (C) 500 ml/day (D) 700 ml/day (B) Loop of Henle 100. The daily water loss through gastrointes- (C) Distal convoluted tubules tinal tract in an adult is about (D) Collecting ducts (A) Less than 100 ml/day 108. A diuretic which is an aldosterone anta- (B) 200 ml/day gonist is (C) 300 ml/day (A) Spironolactone (B) Ethacrynic acid (D) 400 ml/day (C) Acetazolamide (D) Chlorothiazide 101. Recurrent vomiting leads to loss of 109. In a solution having a pH of 7.4, the (A) Potassium (B) Chloride hydrogen ion concentration is (C) Bicarbonate (D) All of these (A) 7.4 nmol/L (B) 40 nmol/L 102. Obligatory reabsorption of water (C) 56 nmol/L (D) 80 nmol/L (A) Is about 50% of the total tubular reabsorption of water 110. At pH 7.4, the ratio of bicarbonate : (B) Is increased by antidiuretic hormone dissolved CO2 is (C) Occurs in distal convoluted tubules (A) 1 : 1 (B) 10 : 1 (D) Is secondary to reabsorption of solutes (C) 20 : 1 (D) 40 : 1

103. Antidiuretic hormone 111. Quantitatively, the most significant buffer (A) Is secreted by hypothalamus system in plasma is (B) Secretion is increased when osmolality of (A) Phosphate buffer system plasma decreases (B) Carbonic acid-bicarbonate buffer system (C) Increases obligatory reabsorption of water (C) Lactic acid-lactate buffer system (D) Acts on distal convoluted tubules and (D) Protein buffer system collecting ducts 104. Urinary water loss is increased in 112. In a solution containing phosphate buffer, the pH will be 7.4, if the ratio of (A) Diabetes mellitus monohydrogen phosphate : dihydrogen (B) Diabetes insipidus phosphate is (C) Chronic glomerulonephritis (A) 4 : 1 (B) 5 : 1 (D) All of these (C) 10 : 1 (D) 20 : 1 105. Diabetes insipidus results from 113. pK of dihydrogen phosphate is (A) Decreased insulin secretion a (B) Decreased ADH secretion (A) 5.8 (B) 6.1 (C) Decreased aldosterone secretion (C) 6.8 (D) 7.1 (D) Unresponsiveness of osmoreceptors 114. Buffering action of haemoglobin is mainly 106. Thiazide diuretics inhibit due to its (A) Carbonic anhydrase (A) Glutamine residues (B) Aldosterone secretion (B) Arginine residues (C) ADH secretion (C) Histidine residues (D) Sodium reabsorption in distal tubules (D) Lysine residues 286 MCQs IN BIOCHEMISTRY

115. Respiratory acidosis results from 123. Anion gap is increased in (A) Retention of carbon dioxide (A) Renal tubular acidosis (B) Excessive elimination of carbon dioxide (B) Metabolic acidosis resulting from diarrhoea (C) Retention of bicarbonate (C) Metabolic acidosis resulting from intestinal (D) Excessive elimination of bicarbonate obstruction (D) Diabetic ketoacidosis 116. Respiratory acidosis can occur in all of the following except 124. Anion gap in plasma is because (A) Pulmonary oedema (A) Of differential distribution of ions across cell (B) Hysterical hyperventilation membranes (C) Pneumothorax (B) Cations outnumber anions in plasma (D) Emphysema (C) Anions outnumber cations in plasma (D) Of unmeasured anions in plasma 117. The initial event in respiratory acidosis is (A) Decrease in pH 125. Salicylate poisoning can cause (A) Respiratory acidosis (B) Increase in pCO2 (C) Increase in plasma bicarbonate (B) Metabolic acidosis with normal anion gap (D) Decrease in plasma bicarbonate (C) Metabolic acidosis with increased anion gap (D) Metabolic alkalosis 118. Respiratory alkalosis can occur in (A) Bronchial asthma 126. Anion gap of plasma can be due to the presence of all the following except (B) Collapse of lungs (C) Hysterical hyperventilation (A) Bicarbonate (B) Lactate (D) Bronchial obstruction (C) Pyruvate (D) Citrate 119. The primary event in respiratory alkalosis 127. All the following features are found in is blood chemistry in uncompensated lactic acidosis except (A) Rise in pH (A) pH is decreased (B) Decrease in pCO 2 (B) Bicarbonate is decreased (C) Increase in plasma bicarbonate (C) pCO is normal (D) Decrease in plasma chloride 2 (D) Anion gap is normal 120. Anion gap is the difference in the plasma concentrations of 128. All the following statements about renal tubular acidosis are correct except (A) (Chloride) – (Bicarbonate) (A) Renal tubules may be unable to reabsorb (B) (Sodium) – (Chloride) bicarbonate (C) (Sodium + Potassium) – (Chloride + (B) Renal tubules may be unable to secrete Bicarbonate) hydrogen ions (D) (Sum of cations) – (Sum of anions) (C) Plasma chloride is elevated 121. Normal anion gap in plasma is about (D) Anion gap is decreased (A) 5 meq/L (B) 15 meq/L 129. All the following changes in blood (C) 25 meq/L (D) 40 meq/L chemistry can occur in severe diarrhoea except 122. Anion gap is normal in (A) Decreased pH (A) Hyperchloraemic metabolic acidosis (B) Decreased bicarbonate (B) Diabetic ketoacidosis (C) Increased pCO (C) Lactic acidosis 2 (D) Increased chloride (D) Uraemic acidosis WATER AND ELECTROLYTE BALANCE 287

130. During compensation of respiratory (C) Move a mass of 1 gm by 1 cm distance by a alkalosis, all the following changes occur force of 1 Newton except (D) Move a mass of 1 kg by 1 m distance by a (A) Decreased secretion of hydrogen ions by force of 1 Newton renal tubules 135. Organic compound of small molecular (B) Increased excretion of sodium in urine size is (C) Increased excretion of bicarbonate in urine (A) Urea (B) Uric acid (D) Increased excretion of ammonia in urine (C) Creatinine (D) Phosphates 131. Blood chemistry shows the following 136. Organic substance of large molecular size changes in compensated respiratory is acidosis: (A) Starch (B) Insulin (A) Increased pCO 2 (C) Lipids (D) Proteins (B) Increased bicarbonate (C) Decreased chloride 137. Body water is regulated by the hormone: (D) All of these (A) Oxytocin (B) ACTH (C) FSH (D) Epinephrine 132. Metabolic alkalosis can occur in (A) Severe diarrhoea 138. Calcium is required for the activation of (B) Renal failure the enzyme: (C) Recurrent vomiting (A) Isocitrate dehydrogenase (D) Excessive use of carbonic anhydrase inhibitors (B) Fumarase (C) Succinate thiokinase 133. Which of the following features are present (D) ATPase in blood chemistry in uncompensated metabolic alkalosis except? 139. Cobalt is a constituent of (A) Increased pH (A) Folic acid (B) Vitamin B12 (B) Increased bicarbonate (C) Niacin (D) Biotin (C) Normal chloride 140. Calcium absorption is inferred by (D) Normal pCO2 (A) Fatty acids (B) Amino acids 134. One joule is the energy required to (C) Vitamin D (D) Vitamin B12 (A) Raise the temperature of 1 gm of water by 141. The average of pH of urine is 1°C (B) Raise the temperature of 1 kg of water by (A) 5.6 (B) 6.0 1°C (C) 6.4 (D) 7.0 288 MCQs IN BIOCHEMISTRY

ANSWERS 1. D 2. A 3. D 4. C 5. C 6. C 7. C 8. D 9. B 10. C 11. B 12. C 13. D 14. D 15. A 16. B 17. A 18. A 19. D 20. A 21. B 22. C 23. A 24. D 25. A 26. B 27. C 28. B 29. B 30. A 31. B 32. D 33. A 34. B 35. C 36. A 37. B 38. A 39. C 40. A 41. B 42. D 43. B 44. B 45. D 46. A 47. C 48. B 49. C 50. A 51. A 52. B 53. C 54. A 55. D 56. A 57. A 58. B 59. B 60. D 61. D 62. D 63. D 64. C 65. A 66. A 67. A 68. A 69. B 70. B 71. C 72. D 73. A 74. B 75. C 76. D 77. C 78. B 79. C 80. A 81. B 82. C 83. B 84. C 85. D 86. D 87. C 88. A 89. C 90. C 91. D 92. C 93. C 94. C 95. A 96. C 97. C 98. B 99. B 100. A 101. B 102. D 103. D 104. D 105. B 106. D 107. B 108. A 109. B 110. C 111. B 112. A 113. C 114. C 115. A 116. B 117. B 118. C 119. B 120. C 121. B 122. A 123. B 124. B 125. C 126. A 127. D 128. D 129. C 130. D 131. D 132. C 133. D 134. D 135. A 136. D 137. A 138. D 139. B 140. A 141. B