S.N . CONTENTS P 1. I 217
2. H 217
3. P S 219
4. C 219 (M - & O - )
5. P 224 6. L 227
7. P 230
8. E -I (C Q ) 238
9. E -II (P Y Q ) 241
10. E -III (A Q ) 244
11. E -IV (A & R ) 245 2019-20
Session
ALLEN
NEET SYLLABUS Chemical constituents of living cells: Biomolecules-structure and function of proteins, carbohydrates, lipids, nucleic acids. FREDERICK SANGER Born on 13 August, 1918 in England. Fredrick Sanger's father was a medical practitioner. He understood the significance of science and the scientific method from an early age. He focused on Chemistry and Physics in the begining but was later attracted to the emerging field of Biochemistry. He received an undergraduate degree and Ph.D. in Biochemistry from St. John's College, Cambridge, England. After graduation Sanger joined the medical research council laboratory of molecular biology as a researcher. Fredrick Sanger received the nobel prize twice for chemistry in 1958 for his discovery of the structure of insulin molecule and in 1980 for his collaborative work on base sequences in nucleic acid with Paul Berg and Walter Gilbert. He passed away on 19 Nov., 2013.
G.N. RAMACHANDRAN An outstanding figure in the field of protein structure, was the founder of the ‘Madras school’ of conformational analysis of biopolymers. His discovery of the triple helical structure of collagen published in Nature in 1954 and his analysis of the allowed conformations of proteins through the use of the ‘Ramachandran plot’ rank among the most outstanding contributions in structural biology. He was born on October 8, 1922, in a small town, not far from Cochin on the southwestern coast of India. His father was a professor of mathematics at a local college and thus had considerable influence in shaping Ramachandran’s interest in mathematics. After completing his school years, Ramachandran graduated in 1942 as the topranking student in the B.Sc. (Honors) Physics course of the University of Madras. He received a Ph.D. from Cambridge University in 1949. While at Cambridge, Ramachandran met Linus Pauling and was deeply influenced by his publications on models of the a-helix and b-sheet structures that directed his attention to solving the structure of collagen. He passed away at the age of 78,2019-20 on April 7, 2001. JAMES DEWEY WATSON was born in Chicago on 6 April 1928. In 1947, he received B.Sc. degree in Zoology. During these years his interest in bird-watching had matured into a serious desire to learn genetics. This became possible when he received a Fellowship for graduate study in Zoology at Indiana University, Bloomington, where he received his Ph.D. degree in 1950 on a study of the effect of hard X-rays on bacteriophage multiplication. He met Session Crick and discovered their common interest in solving the DNA structure. Their first serious effort, was unsatisfactory. Their second effort based upon more experimental evidence and better appreciation of the nucleic acid literature, resulted, early in March 1953, in the proposalALLEN of the complementary double-helical configuration. FRANCIS HARRY COMPTON CRICK was born on 8 June 1916, at Northampton, England. He studied physics at University College, London and obtained a B.Sc. in 1937. He completed Ph.D. in 1954 on a thesis entitled “X-ray Diffraction: Polypeptides and Proteins”. A critical influence in Crick’s career was his friendship with J. D. Watson, then a young man of 23, leading in 1953 to the proposal of the double-helical structure for DNA and the replication scheme. Crick was made an F.R.S. in 1959. The honours to Watson with Crick include: the John Collins Warren Prize of the Massachusetts General Hospital, in 1959; the Lasker Award, in 1960; the Research Corporation Prize, in 1962 and above all, the Nobel Prize in 1962. ALLEN P e-Med ca : B g INTRODUCTION
All living organisms are made up of the same elements and compounds. If we perform an analysis of a plant tissue, animal tissue or a microbial paste, carbon, hydrogen, oxygen and several other elements are obtained. The same analysis made on a non-living matter like a piece of earth's crust, gives a list of similar chemicals. A close examination reveals that the relative abundance of carbon and Hydrogen with respect to other elements is higher in living beings than in earth's crust.
HOW TO ANALYSE CHEMICAL COMPOSITION
l Various biomolecules present in a living tissue (like a vegetable or a piece of liver) can be studied by their chemical analysis. Take a living tissue and grind it in trichloroacetic acid (Cl CCOOH) using a mortar and pestle. We obtain a l 3 thick slurry.
l When we strain this slurry through cheese cloth or cotton, it gives two fractions.
l One is called filtrate or acid soluble pool having thousands of organic compounds.
l Other fraction is called retentate or acid insoluble pool containing proteins, nucleic acid, polysaccharides etc.
l The acid soluble pool contains chemicals with small molecular mass of 18–800 daltons approximately. They are called micromolecules or biomicromolecules. They include amino acids, sugars, nucleotides etc.
l The acid-insoluble fraction contains organic compounds that have molecular weights in the range of ten thousand daltons and above. They are known as macromolecules or biomacromolecules. They include polysaccharides, proteins, nucleic acids. *Lipids are not strictly macromolecules. their molecular weight do not exceed 800 Da, but they come under the l 2019-20 macromolecular fraction because when we grind a tissue, cell membrane and other membrances are broken into pieces and form vesicles which are not water soluble (lipids are also present in structures like cell membrane and other membranes).
l The acid-soluble fraction represents roughly the cytoplasmic composition (without organelles), while the acid- insoluble fraction represents the macromolecules of the cytoplasm and cell organelles. The two fractions together represent the entire chemical composition of living tissues or organisms.
Biomolecule® All the carbon compound that present in living tissue. BiomolecuSessionle
MicromolALLENecule Macromolecule (Mol. Weight < 1000 daltons) (Mol.Weight > 1000 daltons)
Present in acid soluble pool Present in acid insoluble pool eg eg
Amino acids, N2 base, Monosaccharides Protein, nucleic acid, Polysaccharide Special note : Lipids are micromolecules but obtained under macromolecular fraction due to their insoluble nature in aqueous medium of a cell. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 217 P e-Med ca : B g ALLEN
T : Average composition of cells C % Water 70-90 Proteins 10-15 Carbohydrates 3 Lipids2 Nucleic acids 5-7 Ions1
lAll carbon compounds that we get from living tissue can be called - Biomolecules.
l Inorganic elements and compounds are also present in the living organisms which can be known with the help of 'ash' analysis technique.
l A small amount of a living tissue (e.g. Leaf or liver and this is called wet weight) is weighed and dried. All the water evaporates.
When the tissue is fully burnt, the carbon compounds are oxidised to gaseous form like CO , water vapour are l 2 removed and the remnant is called 'ash'. This ash contains many inorganic elements like calcium, magnesium etc.
l In the acid-soluble fraction - inorganic compounds like sulphates, phosphates etc are also present.
Elemental analysis gives composition of living tissue in the form of O, C, H, N etc. l 2019-20 l Analysis of compounds gives an idea of the kind of organic and inorganic constituents as mentained in the table.
Table : A comparison of elements present in non-living and living matter
Element %weight of Earth’s crust Human body
Hydrogen (H) 0.14Session 0.5 Carbon (C) 0.03 18.5 Oxygen (O) 46.6 65.0 Nitrogen (N) Very little 3.3 SulphurALLEN (S) 0.03 0.3 Sodium (Na) 2.8 0.2 Calcium (Ca) 3.6 1.5 Magnesium (Mg) 2.1 0.1 Silicon (Si) 27.7 Negligible : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 218 ALLEN P e-Med ca : B g Table : A list of representative inorganic constituents of living tissues. Component Formula Sodium Na+ Potassium K+ Calcium Ca++ Magnesium Mg++
Water HO2
Compounds NaCl, CaCO3 , 3– 2– PO44 , SO
l From a biological point of view we can classify the biomolecules into micromolecules and macromolecules.
l Water is the most abundant chemical in living organisms. PRIMARY AND SECONDARY METABOLITES
l Living organisms produce thousands of organic compounds (biomolecules) including amino acids, sugars, chlorophylls, haems etc. these are required for their basic or primary metabolic processes like photosynthesis, respiration, protein and lipid metabolism etc. these are called primary metabolites.
l Many plants, fungi and microbes of certain genera and families synthesize a number of organic compounds (biomolecules) which are not involved in primary metabolism and seem to have no direct function in growth and development of organisms. Such compounds are called secondary metabolites.
l Thus, primary metabolites have identifiable functions and play known roles in normal physiological processes. The functions or role of secondary metabolites in host organisms are not understood. However many of them are useful to human welfare (e.g., rubber, drugs, spices, scents and pigments).
T : Some secondary metabolites Pigments Carotenoids, Anthocyanins, etc. Alkaloids Morphine, Codeine, etc. 2019-20 Terpenoides Monoterpenes,Diterpenes etc. Essential oils Lemon grass oil, etc. Toxins Abrin, Ricin Lectins Concanavalin A Drugs Vinblastin, Curcumin, etc. Polymeric substances Rubber, Gums, Cellulose
® Main source of energy. Session ® First respiratory substrate – carbohydrate ® Compounds of Carbon, Hydrogen and Oxygen with ratio of H and O is 2:1, so they are also called as hy- drates of carbon. ALLEN Generalised formula of carbohydrates is C (H O) y. ® x 2 ® Chemically all carbohydrates are polyhydroxy aldehyde or ketones. ® Simple carbohydrates which are soluble in water and sweet in taste are called "Sugar". ® Carbohydrates are main source of energy in body. In a normal man 55-65% of energy is available to him is in the form of carbohydrates present in his diet. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 219 P e-Med ca : B g ALLEN CLASSIFICATION OF CARBOHYDRATES : On the basis of number of saccharide units obtained upon hydrolysis, Carbohydrates are classified as Monosac- charides, Oligo saccharides and Polysaccharides.
A. MONOSACCHARIDES
1. They are simplest sugars which can not be further hydrolysed. 2. In their generalised formula x is mostly equal to y i.e. number of Carbon and Oxygen atoms same. 3. First step of oxidation – Phosphorylation 4. All monosaccharides occur in d and l form, except the Dihydroxy acetone. CH OH 2 | C = O | CH OH 2 Dihydroxy acetone 5. The structure of saccharides is either ring or straight chain. 6. A six membered ring is known as pyranose and five membered ring is furanose. Pyranose and furanose names were given by "Haworth." 7. Anomer – In aqueous solution, Glucose occurs in cyclic structure. In anomers of glucose, position of – H and –OH groups are changed on C carbon atom. 1
H – 1 C = O 6 CH OH 2 2 H – C – OH 5 C O HO – 3C – H H H H 4 2019-20 H – C – OH C C H – 5 C – OH OH 4 OH H 1 OH 6 C C H – C – OH 3 2 H H OH Glucose (Straight chain) a-Glucose (Pyranose structure)
H H – C – OH 6 SessionCH OH 2 C = O 5C O HO – C – H H H OH H – C – OH C C H – C – OH OH 4 OH H 1 H H – CALLEN – OH C C 3 2 H H OH Fructose (Straight chain) b-Glucose
Epimer : Isomer formed as a result of interchange of the –OH and –H groups on carbon atom 2, 3 and 4 of glucose, are known as epimer. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 220 ALLEN P e-Med ca : B g Epimer of Glucose : Mannose (Difference on C carbon) Galactose (Difference on C carbon) 2 4
H OH H OH H OH 1C 1C 1C H – 2 C – OH H – 2 C – OH HO – 2C – H HO – 3C – H O HO – 3C – H O HO – 3C – H O HO – 4C – H H – 4 C – OH H – 4 C – OH H –5 C H –5 C H –5 C 6 6 6 CH2 OH CH2 OH CH2 OH Galactose Glucose Mannose
* Monosaccharides with free aldehyde group are termed as Aldoses (PGAL, Erythrose, Ribose, Arabinose, Deoxyribose, Glucose, Galactose, Mannose).
* While monosaccharides with free ketone group are called ketoses (DHAP, Erythrulose, Ribulose, Xylulose, Fructose, Sedoheptulose).
All monosaccharides are "reducing sugars" as their free aldehyde or ketone groups are capable of reducing Cu++ to Cu+. This property is the basis of Benedict's test or fehling's test used to detect the presence of glucose in urine.
Classification of monosaccharides on the basis of number of carbons :
1. Trioses : Number of carbons = 3 (Simplest monosaccharide)
Common formula = C H O * 3 6 3 e.g. DHAP , PGAL 2019-20
2. Tetroses : Number of carbons = 4
Common formula = C H O * 4 8 4 e.g. Erythrose , Erythrulose
3. Pentose : Number of carbons = 5
Common formula = C H O * 5 10 5 e.g. Xylose Session
Xylulose
Deoxyribose ArabinoseALLEN Ribose
Ribulose : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 221 P e-Med ca : B g ALLEN
Ribose Deoxyribose H – C = O H – C = O H – C – OH H – C – H H – C – OH H – C – OH H – C – OH H – C – OH H – C – OH H – C – OH H H
* Present in RNA, ATP, FAD, FMN, NAD * Present in DNA
Molecular formula = C H O Molecular formula = C H O (Exception) * 5 10 5 * 5 10 4
4. Hexoses : Number of carbons = 6
Common formula = C H O 6 12 6 e.g. Glucose
Fructose
Galactose
Glucose : It is abundant in grapes so known as grape sugar.
* It is abundant in blood also so known as blood sugar.
* Main respiratory substance. 2019-20
* It rotates PPL in right (clockwise) direction so it is dextrorotatory and also known as dextrose.
Fructose :
* Sweetest carbohydrate * More abundant in honey and sweet fruits so also known as fruit sugar. * Rotates PPL in left (anti-clockwise) directionSession so it is laevorotatory and also known as 'Laevulose'. Galactose :
* Most abundant in brain and nervous tissue so called as 'brain sugar'. * It never occursALLEN in free form. It always occurs as a component of some compounds. e.g. Lactose
5. Heptoses : Number of carbons = 7 (Largest monosaccharide)
Common formulae = C H O 7 14 7 e.g. Sedoheptulose : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 222 ALLEN P e-Med ca : B g
B. OLIGO – SACCHARIDES
Oligo – Saccharides are those carbohydrates which on hydrolysis yield 2 to 10 monosaccharide units (mono- mers). In oligosaccharides, monosaccharides are linked together by glycosidic bonds. Aldehyde or ketone group of one monosaccharide reacts with alcoholic group of another monosaccharide to form glycosidic bond. One molecule of H O eliminates during glycosidic bond formation (dehydration synthesis). Direction of glyco- 2 sidic bond is mostly 1'-4".
When another monosaccharide unit is fructose then the direction of linkage is 1'-2". (Non reducing sugars). For e.g. Sucrose
Disaccharides – composed of two monosaccharide units. e.g. Maltose, Sucrose, Lactose, Trehalose.
* All disaccharides are water soluble and sweet in taste, so they are known as sugar.
6 6 CH2 OH CH2 OH O O H 5 H H 5 H H H 4 1 4 1 HO OH H O OH H OH
3 2 3 2 H OH H OH Glucose Glucose Maltose
(i) Maltose
* Maltose is commonly called malt sugar. It is intermediate compound in starch digestion. Maltose has 1'-4" glycosidic linkage between a -D glucose and a-D glucose (ii) Lactose 2019-20 * Lactose is milk sugar with b -1'-4" glycosidic linkage between glucose and galactose
* Lactose is least sweet sugar.
* Maximum % of lactose = Human milk » 7% (iii) Sucrose
* In plants transport of sugars mainly occurs in the form of sucrose. * Sucrose is also known as invert sugar. Session * Sucrose is called Cane Sugar or Table Sugar or Commercial Sugar. Sucrose is composed of a -D Glucose and b-D-fructose. (iv) Trehalose ALLEN * Trehalose is present in haemolymph of insects. It has glycosidic linkage between two anomeric carbons of two a-Glucose units (1–1 linkage). : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 223 P e-Med ca : B g ALLEN
C. POLYSACCHARIDES * Polysaccharides are composed of large number of monosaccharide units. * Suffix '---an' is added in their names and they are known as glycans. * Pentose polysaccharides are called pentosans for e.g. araban (from L- arabinose), xylan (from D-xylose), all these found in cell wall. * Hexose polysaccharides are called "hexans". for e.g. mannan (from mannose) cellulose, starch etc. * Polysaccharides are insoluble in water and do not taste sweet. * All polysaccharide are non-reducing * Although polysaccharides are non reducing but in a polysaccharide chain one end is reducing and another end is non-reducing. * According to function, they are classified as nutritive and structural. On structural basis polysaccharides are of two types. (I) Homopolysaccharides :– Composed of same monomers. Biologically important homopolysaccharides are as follows:
(a) Cellulose :– Linear polymer of b -D-glucose units (6000 to 10,000). It has b 1'-4" linkage. Cellulose is main component of plant cell wall. In wood, cellulose is 50% and in cotton, it is 90%. * Most abundant organic molecule on earth. * It is also used to form Rayon fibre (Artificial silk). * Paper made from plant pulp is cellulose. (b) Starch – It is main stored food in plants. Starch is polymer of a -D-glucose units.2019-20 Starch consists of two types of chains. (i) Amylose :– 250-300 glucose units are arranged in an unbranched chain by a 1'-4" linkage. (ii) Amylopectin :– A branched chain molecule. Approximately 30 glucose units are linked by a - 1',4" and a - 1', 6" linkage. . Amylose gives blue colour with iodine. . Amylopectin gives red colour with iodine. . Starch present in potato contains 20% amyloseSession and 80% amylopectin. Starch forms helical structure so starch can hold I molecules in the helical portion. So starch-I is . 2 2 blue – violet in colour. While cellulose has linear structure so it cannot hold I and does not give Iodine 2 test. (c) Glycogen :– StorageALLEN form of carbohydrate in animals, storage region of glycogen is liver and muscles. Storage of glycogen liver > muscle. Glycogen is also called as animal starch. Glycogen is highly branched polymer of a -D-glucose. . Glycogen is formed by the 1',4" bond linkage in long chain and 1',6" bond linkage at branching point. . Glycogen gives red colour with iodine. . Glycogen is stored food of fungi. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 224 ALLEN P e-Med ca : B g
O CH2 OH CH2 OH O O O OH OH O O O O OH OH OH CH O 2 O O O O
O O O O Diagrammatic representation of a portion of glycogen
(d) Chitin :– Linear polymer of N-acetyl- D-glucosamine with b–1', 4"–linkage. N-acetyl D-glucosamine is an amino acyl (-NH-CO-CH )derivative of -D-glucose. . 3 b . Chitin is an important component of exoskeleton of Arthropods and cell walls of fungi. . Second most abundant organic molecule on earth. . It is also called Fungal cellulose. (e) Inulin :– Linear polymer of fructose units linked with b -1',2" bonds. Inulin is found in roots of Dahlia and Artichoke. It is water soluble polysaccharide and it is used to know the glomerular2019-20 filteration rate. . It is smallest storage polysaccharide. (f) Dextrin – Dextrin is an intermediate substance in the digestion of glycogen and starch. By hydrolysis of dextrin, glucose and maltose are formed. It also occurs as stored food in yeast and bacteria. (II) Heteropolysaccharide :– Composed of different monosaccharide units. (a) Hyaluronic acid – Found in vitreous humour, umbilical cord, joints and connective tissue in the form of lubricating agent. It also occurs in animal cell coat as binding material (Animal cement). (b) Chondroitin – Session . Chondroitin occurs in connective tissue. (c) Heparin – It is anticoagulant of blood. (d) Pectins – ALLEN . Pectin is found in cell wall. . Salts of pectin i.e. Ca and Mg-pectates form middle lamella in plants. . It is also called Plant cement. (e) Hemicellulose – . It is a stored material in Phytelephas (Ivory palm). Hemicellulose which is obtained from this plant is white, hard and shiny and it is used to form billiard balls and artificial ivory. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 225 P e-Med ca : B g ALLEN Slimy polysaccharides with capacity to bind proteins and water are called mucopolysaccharides. In plants, mucilage is a common mucopolysaccharide.
Special Points :
1. Peptidoglycan – Present in cell wall of bacteria.
– Composed of N - acetyl Glucosamine + N - acetyl muramic acid + peptide chain of 4-5 amino acids
2. Agar-Agar – It is a mucopolysaccharide which is obtained from some red algae – Gracilaria, Gelidium, Chondrus. It is composed of D-galactose and L-galactose unit (1, 3 linkage) and after every 10th unit a sulphate group is present. It is used for preparing culture medium.
3. Difference between gums and fevicol : Gums are natural mucoplysaccharides while fevicol is synthetic rubber based adhesive.
' -1 STARTING TO CARBOHYDRATE
1. Which is not true about monosaccharides ?
(1) reducing nature (2) soluble in water (3) sweet in taste (4) always ketose 2019-20
2. Glucose and galactose are two isomeric monosaccharides known as :
(1) Anomers (2) Epimers (3) Sugars (4) Amino sugars
3. Choose the mis-match : (1) Amylose ® contains a-1,4 glycosidic bond. Session (2) K+ ® most abundant mineral element in ICF.
(3) Na+ ® most abundant mineral element in ECF. (4) Cellulose ® violetALLEN colour with iodine solution.
4. Sum total of all the reactions that are taking place in a cell is known as
(1) catabolism (2) anabolism
(3) metabolism (4) redox reaction : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 226 ALLEN P e-Med ca : B g
* Fat and its derivatives are combinaly known as lipid.
* Compounds of C, H, O but the ratio of Hydrogen and Oxygen is not 2:1. The amount of oxygen is consider- ably very less.
* Lipids are insoluble in water and soluble in organic solvents like acetones, chloroform, benzene, hot alcohol, ether etc.
* Lipids occur in protoplasm as minute globules.
* Lipids do not form polymer.
* Lipids provide more than double energy as compared to carbohydrate.
* In animals, fat are present in subcutaneous layer and work as food reservoir and shock-absorber.
* Lipid requires less space for storage as compared to carbohydrate because lipid molecule is hydrophobic and condense.
* Animals store maximum amount of food in the form of lipid.
* Lipids are micromolecules.
* Lipids are calleds fats and oils on the basis of melting point. Oils have lower melting point and fats have higher melting point. * Some lipids also have phosphorus like lecithin. 2019-20 (A) Simple Lipid or Neutral Fats :– * These are esters of long chain fatty acids and alcohol. In majority of simple lipids, the alcohol is a trihydroxy sugar alcohol i.e. glycerol. * Three molecules of fatty acid linked with one molecule of glycerol. The linkage is called "ester bond". Such type of lipids are called as Triglycerides. Three molecules of water are released during formation of triglycerides (dehydration synthesis) * Glycerol is also known as trihydroxy propane. * Similar or different fatty acids participate in the compositionSession of a fat molecule. Simple lipids contain two types of fatty acids.
R – CO OH H O – CH2 R – COO – CH2 ALLENR – CO OH+ H O – CH R – COO – CH+3H O 2
R – COO – CH2 R – CO OH+ H O – CH2 Fatty acid Glycerol Simple lipid (Trihydroxy propane) (Triglyceride) : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 227 P e-Med ca : B g ALLEN * Simple lipids contain two types of fatty acids.
Saturated fatty acid Unsaturated fatty acid
(a) Only single bond, single bonds are present (a) Doble bonds also present with single between C-C atoms bonds between C-C atoms.
(b) Also known as non essential fatty acid, (b) Also known as essential Fatty acid becuase because they can be synthesized in animal they can't be synthesied in animal body, body, so it is not essential to take them with so it is essential to take them with food. food. (c) Lipids with more amount of unsaturated (c) Lipids with more amount of saturated fatty fatty acids are mostly present in liquid acids are mostly present in solid form at form at normal temperature. normal temperature. e.g. Coconut oil, Mustard oil. e.g. Butter, Ghee (d) Metabolicaly they are highly reactive, so (d) Metabolically they are very less reactive. So mostly participate in metabolic reactions. mostly don't participate in metabolism. So So don't have tendency to store in animal have tendency to store in animal body and body. So no obesity, no cholesterol cause obesity. Some amount of saturated formation, no cardio vascular disease, no fatty acids convert into cholesterol in liver. high B.P. & no harmful effect. This cholesterol deposit on inner wall of blood vessels, so cause high blood pressure & different types of cardio-vasular disease. (e) Mostly palnt fat contains high amount of (e) Mostly animal fat contains high amount of unsaturated fatty acids. saturated fatty acids. (f) Example No. of Examples No. of C double Palmitic acid = 16 bonds Stearic acid = 18 MUFA Oleic acid 2019-20= 1 Monounsaturated fattryacid
Linoleic acid = 2 PUFA Polyunsaturated Linolenic acid = 3 fattryacid Arachidonic acid = 4
Waxes are monoesters with only one molecule of fatty acid attached to a monohydroxy alcohol.
e.g. Spermaceti In skull of whale and Dolphin. Session (B) Conjugated or Compound Lipids :–
(1) Phospholipids or phosphatide or phospholipins :–
2 Molecules of fatty acid + Glycerol + H PO + Nitrogenous compound. Phospholipids are most abun- ALLEN3 4 dant type of lipids in protoplasm.
Phospholipids have both hydrophilic polar end (H PO and nitrogenous compound) and hydrophobic 3 4 non polar end ( fatty acids). Such molecules are called amphipathic. Due to this property, phospholipids form bimolecular layer in cell membrane. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 228 ALLEN P e-Med ca : B g Some biologically important phospholipids are as following :
(a) Lecithin or Phosphatidyl choline
* Nitrogenous compound in lecithin is choline O
O CH21 –O–C–R
R2 –C–O–CH O
CH2 –O–P–O–CH22–CH OH N+ CH3 CH3 Phospholipid (Lecithin) CH3
(b) Cephalin–Similar to lecithin but the nitrogenous compound is ethanolamine, cephalin occurs in nervous tissue, egg yolk and blood platelets.
(c) Sphingolipids or sphingomyelins similar to lecithin but in place of glycerol it contains an amino alcohol sphingosine.
Sphingolipids occur in myelin - sheath of nerves.
(2) Glycolipid :– 1 fatty acid + sphingosine + galactose
eg. Cerebroside which occurs in white matter of brain -
Gangliosides - These occur in nerve ganglia and spleen. (c) Derived Lipids :– Lipid derived from simple or conjugated lipid .Derived lipids are complex in struc- ture. They are insoluble in water and soluble in organic solvents
(1) Steroids :– Steroids exhibit tetracyclic structure called "Cyclo pentano perhydrophenanthrene nucleus" 2019-20 On the basis of functional group, steroids are of two types -
(a) Sterols :– Alco h o li c s t e ro i d s e . g . cholesterol – Cholesterol abundantly occurs in brain, nervous tissue , Adrenal gland and skin. Cholesterol is a parent steroid. Several other biologically important steroids are derived from cholesterol.7 - dehydro cholesterol which occurs in skin is a provitamin. On exposure to ultraviolet radiation, it transforms in cholecalciferol i. e vitamin D * Cholesterol is also called "most decoratedSession micromolecule in biology".
ALLENCholesterol HO (b) Sterones :– Ketonic steroids, for e. g. sex hormones, Adreno corticoids , ecdyson hormone of insects (2) Chromolipid = It is also called terpene. * Most complex lipid in protoplasm. * Chromolipids composed of repeated isoprene units : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 229 P e-Med ca : B g ALLEN Protein name is derived from a greek word which means " holding first place" (Berzelius and Mulder) * Essential elements in protein are C , H , O, N, * Most of the proteins contain sulphur. In some proteins iodine , iron and phosphorus are present. * After water, proteins are most abundant compounds in protoplasm. (7-14%) amount of proteins. * Proteins are polymers of amino acids (Fisher and Hofmeister). There are approximately 300 amino acids known to exist but only 20 types of amino acids are used in formation of proteins
* Proteins are heteropolymers of amino acid.
* Amino acids contain an amino group and carboxylic group on the same carbon i.e. the a-carbon so they are called a-amino acids. * Amino acids are substituted methanes.
H CH3 CH 2 – OH
NH 2 — C — COOH NH 2 — C — COOH NH 2 — C — COOH
H H H Glycine Alanine Serine Amino acids is amphoteric compound because it contains one acidic -COOH and an alkaline group -NH * 2 * At isoelectric point, amino acid is present in form of zwitter ion. 2019-20 R R NH+ C COOH NH C COO 3 2 H H
Zwitter ion * Iso electric point is that point of pH at which amino acids do not move in electric field. * Out of 20 amino acids, 10 amino acids are not synthesized in body of animals so they are must in diet. These are called Essential amino acid . e. g. ThreonineSession , Valine, Leucine, Isoleucine, Lysine, Methionine, Phenylalanine Tryptophan, Arginine, Histidine. Arginine and Histidine are semi essential. * 10 amino acids are synthesized in animal body so these are called Non essential amino acids. for e.g. Glycine, Alanine, Serine, Cysteine,Aspartic acid, Glutamic acid, Asparagine, Glutamine, Tyrosine, Proline Except glycine,ALLEN each amino acid has two enantiomeric isomers
D–amino acid L–amino acid : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 230 ALLEN P e-Med ca : B g * Most proteins have L- amino acids while D- amino acids occur in peptidoglycan of bacterial cell wall and antibodies.
Amino acids are joined with peptide bond to form proteins.
Peptide bond H H
HN2 C C N C C OH + H2 O R O H R O
Dipeptide
* Peptidyl transferase enzyme catalyses the synthesis of peptide bond. * Property of protein depends (i) on sequence of amino acid and (ii) configuration of protein molecules.
N C
OH
COOH
SH CH2
CH2 OH CH2 CH2 CH2 –HN–CH–CO–NH–CH–CO–NH–CH–CO–NH–CH–CO– Aminoacid 2019-20 Residue: n–2 n–1 n n+1 Serine Cysteine Tyrosine Glutamic acid (Ser) (Cys) (Tyr) (Glu) (S) (C) (Y) (E)
Primary structure of a portion of a hypothetical protein. N and C refer to the two termini of every protein. Single letter codes and three letter abbreviations for amino acids are also indicated. Classification of amino acids on the basis of numberSession of carboxylic groups and Amino groups. 1. Acidic amino acid * They have one amino and two carboxylic groups in their structure.
NH NH 2 ALLEN3 COOH COO Net charge = –ve, so they move towards anode in electric field. COOH COO
CH22 –CH –COOH e.g. – Glutamic acid ® H2 N–C–COOH H
: N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 – Aspartic acid 231 P e-Med ca : B g ALLEN 2. Alkaline amino acid * They have two amino and one carboxylic group.
NH2 NH3 NH NH 2 3 ® Net charge = +ve, so they move towards cathode in electric field. COOH COO e.g. Histidine Arginine Lysine 3. Neutral AA * They have one amino and one carboxylic group. * They are present in the form of zwitter ion and show no movement in electric field. e.g. Rest 15 AA
Special Points on Amino acid :
1. Tryptophan : Most complex amino acid and helpful in synthesis of I.A.A. (Indole-3-Acetic Acid) which is plant growth hormone.
2. Tyrosine : Helps in synthesis of melanin pigment, Thyroxine hormone, Adrenaline (epinephrine) hormone, Nor adrenaline (Nor epinephrine) Hormone.
3. In proline amino acids, imino group (–NH) is present instead of amino (–NH ) group so these two amino 2 acids are also known as imino acids.
4. Cysteine and methionine are sulphur containing amino acids.
Tyrosineü Aromatic AA ï 2019-20 5. Tryptophaný because they have Phenyl alanineï benzene ring in their structure. þ 6. Except glycine all amino acids are laevorotatory.
7. Glycine is the simplest and Tryptophan is most complex Amino acid.
8. Amino acids which participate in protein synthesis are called as protein Amino acids and those which do not participate are called as non-protein amino acids. eg. GABA, Ornithine, Citrulline. Session Configuration of Protein Molecule :– (1) Primary configuration or structure :– A straight chain of amino acids linked by peptide bonds form primary structure of proteins. This structure of proteins is most unstable. Newly formed proteins on ribosomes have primary structure.ALLEN (2) Secondary configuration :– Protein molecules of sec. structure are spirally coiled. In addition to peptide bond, amino acids are linked by hydrogen bonds between oxygen of one amide group and hydrogen of another amide group. This structure is of two types - 1 i –Helix :– Right handed rotation of spirally coiled chain with approximately 3 amino acids in each () a 2 turn. This structure has intramolecular hydrogen bonding i. e. between two amino acids of same chain e.g. Keratin ,Myosin, Tropomyosin. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 232 ALLEN P e-Med ca : B g (ii) b- Helix or pleated sheath structure :- Protein molecule has zig - zag structure. Two or more protein molecules are held together by intermolecular hydrogen bonding. e.g. Fibroin (silk). . Proteins of sec. structure are insoluble in water and fibrous in appearance. . Keratin is a fibrous , tough, resistant to digestion, sclero protein.Hard ness of keratin is due to abundance of cysteine amino acid in its structure. (3) Tertiary Structure :– Proteins of tertiary structure are highly folded to give a globular appearance. They are soluble in water (colloid solution). This structure of protein has following bonds– (i) Peptide bonds = strongest bond in proteins. (ii) Hydrogen bonds (iii) Disulphide bond :– These bonds are formed between - SH group of amino acid (Cysteine). These bonds are second strongest bond and stabilise tertiary structure of protein. (iv) Hydrophobic bond : Between amino acids which have hydrophobic side chains for e.g. Aromatic amino acid (v) Ionic bond : Formation of ionic bond occurs between two opposite ends of protein molecule due to electrostatic attraction Majority of proteins and enzymes in protoplasm exhibit tertiary structure. (4) Quaternary Structure :– Two or more polypeptide chains of tertiary structure unite by different types of bond to form quaternary structure of protein. Different polypeptide chains may be similar (lactic-dehy- drogenase) or disimilar types (Haemoglobin, insulin). Quaternary structure is most stable structure of protein.
2019-20
N
C (a) (b) Cartoon showing : (a) A secondarySession structure and (b) A tertiary structure of proteins Denaturation of protein :- * Besides changes in pH, salts, heavy metals, temperature, pressure, etc. also cause precipitation of proteins. Because of these changes,ALLEN the secondary and tertiary configuration of proteins is destroyed. Such alternations in the physical state of proteins is called denaturation. If the change in the medium of protein is mild and for a short period, then denaturation of the protein is also temporary, however, if the change in medium is strong and prolonged then denaturation is permanent and the protein becomes coagulated. For example, the white or albumen of egg is a soluble globular protein but on heating it permanently coagulates into fibrous insoluble form. It is clear, that strong alternations result in the denaturation of proteins and they lose their biological properties and significance. It is this reason, that cells of organisms are unable to bear strong changes and they ultimately die. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 233 P e-Med ca : B g ALLEN
Types of protein
Simple Compound Derived (made up of only amino acids)
Fibrous Globular Long, Coiled & Thread like Rubisco :- – Present in chloroplast. Collagen :- –Most abundant protein on the earth . – Most abundant protein in animal body – 1/3 part of total proteins Albumin :- – Present in connective tissue – Maintain B.C.O.P. – Threads of collagen known as Tendon – In milk as Lactoalbumin – In egg yolk as Ovalbumin Elastin :- – In blood as Serum albumin – In connective tissue Globin :- Present in Haemoglobin. – Threads of Elastin known as Ligament
Keratin Histone protein :- Present with eukaryotic DNA. – In it Lysine & Arginine A.A. are present in more amount.
Compound protein
Protein part Non-protein part non amino acid part2019-20 Made up of A.A. (Prosthetic group)
* Types of compound protein on the basis of prosthetic group.
1. Nucleoprotein :- Prosthetic group is nucleic acid.
eg. Chromosome = DNA + RNA + Protein
Ribosome = rRNA + Protein Virus Session 2. Chromoprotein :- Prosthetic group is Porphyrin pigment (metal + porphyrin ring)
eg. Metal Colour Haemoglobin ALLENFe Red Cytochrome Fe Red
Haemocyanin Cu Blue
3. Lipoprotein :- Prosthetic group is lipid
eg. Plasma membrane : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 234 ALLEN P e-Med ca : B g 4. Phosphoprotein :- Prosthetic group is phosphoric acid (H PO ) 3 4 ® Caseinogen - Milk
® Pepsin - Protein digesting emzyme. 5. Lecithoprotein :- Prosthetic group is Lecithin
eg. Fibrinogen - Blood
6. Metalloprotein :- Prosthetic group is metal
eg. Enzyme with its co-factor
7. Glycoprotein :- Prosthetic group is carbohydrate (less than 4% carbohydrate)
eg. (1) a, b, g globulin of blood. Glycoproteins which are present on cell surface are helpful in cell recognition.
Human = Egg surface - Fertilizin - Glycoprotein
Sperm surface - Antifertilizin - Simple protein.
8. Mucoprotein Prosthetic group is carbohydrate (more than 4% carbohydrate) Special Points on Protein : * Monomeric protein : Protein composed of one polypeptide chain. * Oligomeric/Polymeric/Multimeric protein : Protein composed of more then one polypeptide chains. Some proteins and their functions
Protein Functions Collagen Intercellular ground substance 2019-20 Trypsin Enzyme
Insulin Hormone
Antibody Fights infectious agents
Receptor Sensory reception (smell, taste, hormone, etc.)
GLUT-4 Enables glucose transport into cells Session
l Chitin is an example of Homopolysaccharide. l In proteins only rightALLEN handed helix are observed. l Cellulose never show iodine test.
l Phospholipids are most abundant lipid in cell membrane.
l Thaumatine is sweetest chemical substance which is obtained from Thaumatococcus danielli bacteria.
l Aspartame/Aspartin is most commonly used artificial sweetener. It is non carcinogenic. : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 235 P e-Med ca : B g ALLEN ' -2
LIPID TO PROTEIN
1. The most abundant lipids in eukaryotic cell membrane are (1) cholestrol (2) glycolipids (3) phospholipids (4) lipopolysaccharide
2. Which of the following is alkaline amino acid (1) glycine (2) valine (3) alanine (4) arginine
3. Which biomolecule release maximum energy during oxidation (1) lipid (2) protein (3) nucleic acid (4) carbohydrate
4. An alpha helix represents (1) primary structure of protein (2) aggregation of protein (3) secondary structure of protein (4) tertiary structure of protein
5. Which of the following bond is/are found in tertiary structure of protein (1) peptide bond & hydrogen bond (2) disulphide & hydrophobic bond (3) ionic bond (4) all the above 2019-20 ALLENSession : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 236 ALLEN P e-Med ca : B g NCERT BASED PROBLEMS
1. What are macromolecules? Give examples. Ans. Macromolecules are large sized, high molecular weight, complex molecules, which are formed by polymerisation or condensation of small sized, low molecular weight, simple molecules. e.g. Protein, Nucleic acid and Polysaccharides. 2. Protein having primary structure. If you are given a method to know, which amino acid is at either of the two termini (ends) of a protein. Can you connect this information to purity or homogeney of a protein? Ans. No, because we know about the first and last amino acids, but in between them any type of amino acids may present, for those we can not be sure. 3. Find out and make a list of proteins, used as therapeutic agents. Ans. Proteins those are engineered in the laboratory for pharmaceutical uses are known as therapeutic proteins. e.g. Monoclonal antibodies, Interferons, Insulin, Erythropoetin. 4. Can you describe, what happens ? when milk is converted into curd or yoghurt, from your understanding of proteins ? Ans. Denaturation (Coagulation) of proteins, present in milk, due to change in pH and temperature. 5. Can you attempt models of biomolecules, using commercially, available atomic models (ball and stick models). Ans. In ball and stick model, ball is used for atoms and short rod of wood / plastic is used to represent bonds of a compound. 6. What are gums made of ? Is fevicol different ? Ans. Gums are colloidal exudates of plant, which are chemically polysaccharide, while fevicol is synthetic rubber based adhesive. 7. Find out a qualitative test for protein, fat, oils and amino acid. Ans. Protein ® Biuret test
® Alkaline CuSO4 - reagent test ® Violet colour test Fat and Oils 2019-20 Grease spot test ® A drop of oil placed over a piece of simple paper, a translucent spot is visible. This indicates the presence of fat. Amino acids ® There are different tests available for different amino acids. Ex : Test Reagents Colour Amino acid
Millon's test HgNO3 in HNO2 Red Tyrosine and Tryptophan
Xanthoproteic test Conc. HNO3 Yellow Tyrosine, Tryptophan, SessionPhenylalanine
8. Briefly describe the bioinformatics. Ans. Bioinformatics is the collecting, storage and analysis of large amount of biological data in computer, to make useful conclusions. These data contain mapping and phenotype informations, nucleotide and amino acids sequence and structureALLEN and function of proteins. ANSWER KEY
Que. 1234 BEGINNER'S BOX-1 Ans.4243
Que. BEGINNER'S BOX-2 12345 Ans.34134 : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 01- -E. 65 237 P e-Med ca : B g ALLEN EXERCISE-I (C Q ) B U Y U
1. Decreasing order of organic compound in proto- 11. Monosaccharide is - plasm is:- (1) Pentose Sugar (2) Hexose Sugar (1) Protein, lipid, Nucleic acid, Vitamin (3) Only Glucose (4) all the above (2) Protein, Nucleic acid, carbohydrate, lipid 12. Sugar which is found in haemolymph of insects is (3) Carbohydrate, Lipid, Nucleic acid and vitamin called- (4) None of these (1) Maltose (2) Lactose (3) Trehalose (4) Galactose 2. Which is odd - (1) Chitin - Carbohydrate 13. Which substance is most abundant in cell ? (2) Pectin - Protein (1) Carbohydrates (2) Proteins (3) Water (4) Fats (3) Steroid - Lipid (4) Wax - Lipid 14. Proteins present in cells are very important be- cause- 3. Glycogen is stored in - (1) They provide definite shape to cell (1) Liver and muscles (2) Liver only (2) They function as biocatalyst (3) Muscles only (4) Pancreas (3) They yield energy (4) They are stored food 4. Which one is a disaccharide ? 15. Dipeptide is- (1) Galactose (2) Fructose (1) Structure of two peptide bonds (3) Maltose (4) Dextrin (2) Two amino acids linked by one peptide bond (3) bond between one amino acid and one peptide 5. Which element is normally absent in proteins ? (4) None (1) C (2) N (3) S (4) P 16. Which amino acid is non essential for human body? (1) Glycine 2019-20(2) Phenylalanine 6. Which substance is not a carbohydrate ? (3) Arginine (4) Methionine (1) Starch (2) Glycogen 17. Nails, horns and hooves contain - (3) Wax (4) Glucose (1) Chitin (2) Keratin 7. To get quick energy one should use - (3) Both (4) None (1) Carbohydrate (2) Fats 18. Essential component of all living organisms (3) Vitamins (4) Proteins (1) Hemoglobulin (2) Protein (3) Chlorophyll (4) Carbohydrate 8. Most abundant protein in human body is- Session (1) Collagen (2) Myosin 19. Glycogen is - (3) Actin (4) Albumin (1) Polymer of amino acids (2) Polymer of fatty acids 9. Which is not polysaccharide ? (3) Unsaturated fats (1) Sucrose ALLEN(2) starch (4) Polymer of glucose (3) Glycogen (4) cellulose 20. Carbohydrate is - 10. Common in feather and Silk is- (1) Polymers of fatty acid (1) Carbohydrate (2) Fats (2) Polymer of amino acids (3) Protein (4) Nucleic acid (3) Polyhydroxy aldehyde or ketone (4) None : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 238 E ALLEN P e-Med ca : B g 21. In which form, food is stored in animal body ? 32. Fats in the body are formed when :- (1) Glucose (2) Glycogen (1) Glycogen is formed from glucose (3) Cellulose (4) ATP (2) Sugar level becomes stable in blood (3) Extra glycogen storage in liver and muscles is 22. Which compound produces more than twice the stoppped amount of energy as compared to (4) All of them carbohydrates? (1) Protein (2) Fats 33. For body growth and repair one needs :- (3) Vitamins (4) Glucose (1) Carbohydrates (2) Fats (3) Proteins (4) Vitamins 23. Carbohydrates are stored in mammals as : (1) Glucose in liver 34. In India the best source for proteins in herbivo- (2) Glycogen in muscles and spleen rous persons is- (3) Lactic acid in muscles (1) Pulses (2) Potato (4) Glycogen in liver and muscles (3) Egg (4) Meat
24. Which one of the following is polysaccharide? 35. Proteins are conducted in the body in the form of:- (1) Sucrose (2) Lactose (1) Amino acids (2) Natural proteins (3) Glycogen (4) Glucose (3) Enzymes (4) nucleic acids
25. Starving person will first use :- 36. Which is sweet in taste, but is not sugar- (1) Fats (2) Glycogen (1) Starch (2) Saccharine (3) Blood protein (4) Muscle protein (3) Lactose (4) Protein
26. Units of proteins which unite in long chains to 37. The formation of protein can be considered as : form proteins, are called- (1) Dehydration synthesis (1) Sugar (2) Purines (2) Dehydration analysis (3) Pyrimidines (4) Amino acids (3) Hydration synthesis (4) Hydration analysis 27. Milk protein is- 2019-20 (1) Lactogen (2) Myosin 38. Translocation of sugars in flowering plants occurs (3) Casein (4) Pepsin in the form of - (1) Glucose (2) Sucrose 28. Chemically enzymes are :- (3) Fructose (4) Maltose (1) Fats (2) Carbohydrates 39. Sucrose is composed of - (3) Hydrocarbons (4) Proteins (1) Glucose & Fructose 29. Most simple amino acid is- (2) Glucose & Glycogen (1) Tyrosine (2) Lysine (3) Two molecules of Glucose (3) Glycine (4) Aspartic acids Session(4) Glycogen & Fructose 40. Which of the following amino acid is essential - 30. The amino acids which are not synthesized in the (1) Alanine (2) Glycine body are called : (3) Tryptophan (4) Tyrosine (1) Non-essentialALLEN (2) Essential (3) Deaminated (4) All of them 41. Which of the following disaccharides will give two molecules of glucose on hydrolysation 31. Which of the following will be different in differ- (1) Maltose (2) Sucrose ent animals :- (3) Lactose (4) None (1) Fats (2) Carbohydrates (3) Proteins (4) Vitamins 42. Which is very most structural part of the body - (1) Protein (2) Carbohydrates (3) Lipid (4) Nucleic acid : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 E 239 P e-Med ca : B g ALLEN 43. Which of the following sugar is found in ATP 49. Sweetest sugar among the naturally occuring sug- (1) Deoxyribose (2) Ribose ars is :- (3) Trehalose (4) Glucose (1) Glucose (2) Fructose 44. Deficiency of protein leads to - (3) Sucrose (4) Saccharine (1) Rickets (2) Scurvy 50. Histone is a basic protein due to - (3) Kwashiorkor (4) Carotenemia (1) Alanine & glycine 45. Lactose is composed of - (2) Methionine & serine (1) Glucose + galactose (2) Glucose + fructose (3) Tryptophan & tyrosine (3) Glucose + glucose (4) Glucose + mannose (4) Lysine & Arginine
46. True statement for cellulose molecule - 51. Sugar with five membered ring called - (1) b - 1'- 4" linkage. unbranched (1) Pyranose (2) Furanose (2) b - 1'- 4" linkage. branched (3) Dextrorotatory (4) Laevortatory (3) a - 1' - 4" linkage, branched (4) b - 1' - 6" linkage unbranched 52. Which sugar occurs only in mammals ? (1) Trehalose (2) Galactose 47. Variations in proteins are due to - (3) Lactose (4) Mannose (1) Sequence of amino acids (2) Number of amino acids 53. Which sugar does not give Benedict's test ? (3) R - group (1) Glucose (2) Maltose (4) None (3) Fructose (4) Sucrose
48. The antibodies are - 54. Amylose and Amylopectin chains occur in - (1) g (Gamma) - globulins (1) Glycogen (2) Starch (2) Albumins (3) Cellulose (4) Chitin (3) Vitamins (4) Sugar 55. Which protein is found in maximum amount ? (1) Catalase 2019-20 (2) Zinc carbonic anhydrase (3) Transferase (4) RUBISCO
Session
EXERCISE-I (C Q ) ANSWER KEY Que. 1 2 3ALLEN 4 5 6 7 8 9 10 11 12 13 14 15 Ans.221343111343322 Que. 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Ans.122432243243432 Que. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Ans.333112121311231 Que. 46 47 48 49 50 51 52 53 54 55 Ans.1112423424 : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 240 E ALLEN P e-Med ca : B g EXERCISE-II (P Y Q ) AIPMT/NEET & AIIMS (2006-2018)
AIPMT 2007 AIPMT (Pre.) 2012
1. Which monosaccharide does not show optical 6. Which one of the following sets of monoseccharides isomerism : forms sucrose? (1) -D-Glucopyranose and (1) Dihydroxy acetone (2) Glyceraldehyde b a-D-fructofuranose (3) Erythrose (4) Ribose (2) a-D-Glucopyranose and -D-fructopyranose 2. Which one of the following is not a constituent of cell b (3) -D-Galactopyranose and membrane ? a a-D-Glucopyranose (1) Phospholipids (2) Cholesterol (4) a-D-Glucopyranose and (3) Glycolipids (4) Proline b-D-fructofuranose AIIMS 2010 7. Which one out of A - D given below correctly 3. Lactose is made up of :- represents the structural formula of the basic amino (1) b-glucose & a-glucose acid ? (2) Glucose & Mannose (3) b-glucose & b-galactose NH2 NH2 CH2 OH NH2 (4) Glucose & Fractose H–C–COOH H–C–COOH CH2 H–C–COOH CH CH CH CH 4. Correct order of abundance of oxygen, sulphur, 2 2 2 2 CH OH NH CH magnesium and calcium in the earth crust ? 2 2 2
C CH2 (1) O > Ca > Mg > S OH O CH2 (2) S > O > Mg > Ca NH 2019-202 (3) Ca > O > S > Mg Options (4) Mg > Ca > S > O (1) A (2) B (3) C (4) D
8. Which one is the most abundant protein in the AIPMT (Pre.) 2011 animal world ? 5. Which one of the following structural formulae of two (1) Collagen organic compounds is correctly identified along with (2) Insulin its related function ? (3) Trypsin Session(4) Haemoglobin O NH2 CH –O–C–R O 2 N NEET-UG 2013
R2 –C–O–CH O N CH –O–P–O–CH –CH 2 22 9. The most abundant intracellular cation is : OH N + + CH CH N NH (1) K (2) Na 3 CHALLEN3 3 A B (3) Ca++ (4) H+
10. Macro molecule chitin is : (1) B : adenine - a nucleotide that makes up nucleic acids (1) Simple polysaccharide (2) A : Triglyceride - major source of energy (2) Nitrogen containing polysacchairde (3) B : Uracil - a component of DNA (3) Phosphorus containing polysaccharide (4) A : Lecithin - a component of cell membrane (4) Sulphur containing polysaccharide : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 E 241 P e-Med ca : B g ALLEN AIPMT 2014 AIIMS 2016
11. Which one of the following is a non - reducing 17. Match the column-I with column-II and choose correct option :- carbohydrate ? (1) Maltose Column-I Column-II (2) Sucrose (3) Lactose Fights infectious AInsulini (4) Ribose agents Enables glucose Re-AIPMT 2015 B Antibody ii transport into cells
12. The chitinous exoskeleton of arthropods is formed C Receptor iii Hormone by the polymerisation of : (1) lipoglycans D GLUT-4 iv Sensory reception (2) keratin sulphate and chondroitin sulphate (1) A-iii, B-ii, C-iv, D-i (3) D-glucosamine (2) A-iii, B-i, C-iv, D-ii (4) N-acetyl glucosamine (3) A-i, B-ii, C-iii, D-iv (4) A-ii, B-iii, C-iv, D-i AIIMS 2015 18. Match the following :- 13. Which of the following pair of amino acid have positive charge at pH = 7 :- Column-I Column-II (1) Asp - glu a Alkaloid I Vinblastin, curcumin (2) Lys - Arg (3) Gly - Ala b Essential oils II Morphine, Codeine (4) Asp - gly c Toxins III Lemon grass oil
NEET-I 2016 d Drugs IV2019-20 Abrin, Ricin 14. One of the major components of cell wall of most (1) a-II, b-III, c-IV, d-I fungi is :- (2) a-III, b-II, c-IV, d-I (3) a-II, b-III, c-I, d-IV (1) Chitin (2) Peptidoglycan (4) a-III, b-II, c-I, d-IV (3) Cellulose (4) Hemicellulose 19. Glycoprotein contains :- 15. A typical fat molecule is made up of :- (1) More than 200 amino acids and carbohydrate (1) Three glycerol molecules and one fatty acid as its side chain molecule Session(2) More than 20 amino acids and carbohydrate as (2) One glycerol and three fatty acid molecules its side chain (3) One glycerol and one fatty acid molecule (3) More than 200 amino acids and steroids as its (4) Three glycerol and three fatty acid molecules side chain (4) More than 20 amino acids contains steroids as NEET-IIALLEN 2016 its side chain 16. Which of the following is the least likely to be NEET(UG) 2017 involved in stabilizing the three–dimensional folding 20. Which of the following are not polymeric ? of most proteins? (1) Hydrophobic interaction (1) Proteins (2) Ester bonds (2) Polysaccharides (3) Hydrogen bonds (3) Lipids (4) Electrostatic interaction (4) Nucleic acids : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 242 E ALLEN P e-Med ca : B g 24. Choose the correct match for the figures given NEET(UG) 2018 below:- 21. The two functional groups characteristic of sugars CH OH are 2 HOCH2 O (1) hydroxyl and methyl O (2) carbonyl and methyl OH OH (3) carbonyl and phosphate HO OH OH (4) carbonyl and hydroxyl OH (B) 22. Which of the following is an amino acid derived (A) hormone ? O (1) Epinephrine (2) Ecdysone NH2 (3) Estradiol (4) Estriol N HN N AIIMS 2018 NH O N 23. Glycine amino acid is coded by :- N H (1) CCC, CCG, CCA (C) (D) (2) GGG, GGC, GGU (1) A-uracil, B-adenine, C-glucose, D-ribose (3) UUU, UUC, UUA (2) A-glucose, B-ribose, C-adenine, D-uracil (4) AAA, AAC, AAG (3) A-ribose, B-glucose, C-uracil, D-adenine (4) A-adenine, B-uracil, C-ribose, D-glucose
2019-20 ALLENSession
EXERCISE-II (P Y Q ) ANSWER KEY Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ans.143144411224212 Que. 16 17 18 19 20 21 22 23 24 Ans.221134122 : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 E 243 P e-Med ca : B g ALLEN EXERCISE-III (A Q ) C Y U 1. Which element is present negligible in human body? 15. Following structure is related to which AA? (1)O (2) C (3) H (4) Si COOH 2. Which of the following compound is found in acid H–C–NH soluble pool during analysis of a living tissue? 2 CH (1) Protein (2) Lipid 3 (3) Polysaccharide (4) Monosaccharide (1) Glycine (2) Alanine 3. Which of the following is not a macromolecule? (3) Serine (4) Tyrosine (1) Amino acid (2) Nucleotide 16. Following structure is – (3) Monosaccharide (4) All the above CH –OH 4. Valine amino acids is – 2 OH (1) a-AA (2) b-AA H C O (3) g-AA (4) All the three types H C C 5. a-amino acids are those, which – OH H (1) Participates in protein synthesis HO C C H (2) –COOH group and –NH group are attached 2 H OH on same carbon (3) 20 types (1) a-Glucose (2) b-Glucose (4) All the above are correct (3) Ribose (4) Deoxyribose 6. Which of the following is correct statement ? 17. Which of the following is secondary metabolites? (1) Amino acids may be considered as substituted (1) Rubber (2) Alkaloids methane (3) Terpenoids (4) All the above (2) a-AA have difference only in R group 18. Which of the following statement is correct? (3) In serine, R-group is hydroxy methyl (1) Lipid is biomacromolecule (4) All the above (2) Lipid has <1000 daltons molecular weight 7. What is the R group in Glycine? (3) Proteins are heteropolymer (1) –CH –OH (2) –H (4) All the above are correct except (1) 2 (3) –CH (4) None of them 19. DNA is – 3 8. Which of the following is acidic amino acid? (1) Biomacromolecule (1) Valine (2) Glutamic acid (2) Acidic in nature (3) Arginine (4) Lysine (3) Polymer of nucleotide 9. Which of the following is aromatic AA? (4) All the above 2019-20 (1) Tyrosine (2) Tryptophan 20. Which statement is a false statement ? (3) Phenyl alanine (4) All the above (1) Glycerole is trihydroxy propane 10. How many total carbons ar present in palmitic acid? (2) Cellulose does now show iodine test (1) 15 (2) 16 (3) The concentration of glucose in blood in an (3) 17 (4) 20 adult man is 4.5–5.0 mM 11. Which of the following is component of simple lipid? (4) Lipids are macromolecule (1) Glycerol (2) Glycol 21. Corn is immersed in the boiling water. It is then (3) Fatty acid (4) both 1 & 3 cooled, the solution becomes sweet. It is due to:- 12. Lipids may be (1) Enzymes are inactivated in boiling water (1) Monoglyceride (2) Diglyceride (2) Disaccharides are converted to monosaccharides (3) Triglyceride (4) All the above (3) Monosaccharides are converted to disaccharides 13. The lipid which is found in cell membrane is Session(4) None of these (1) Phospholipid (2) Lecithin 22. All the following statements about the structure of (3) 1 & 2 both (4) Palmitic acid glycogen are true, except :- 14. Heterocyclic ring is found in which compound? (1) Branched chains occur, after every ten residues (1) N-bases (2) It is a copolymer of glucose and mannose (2) Ring strucuture ofALLEN monosaccharides (3) It contains a–1, 4–glycosidic linkages (3) Protein (4) It contains a–1, 6–glycosidic linkages (4) 1 & 2 both
EXERCISE-III (A Q ) ANSWER KEY Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ans.444144224244342 Que. 16 17 18 19 20 21 22 Ans.2444422 : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 244 E ALLEN P e-Med ca : B g EXERCISE-IV (A & R ) T AIIMS Directions for Assertion & Reason questions These questions consist of two statements each, printed as Assertion and Reason. While answering these Questions you are required to choose any one of the following four responses. (A) If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion. (B) If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion. (C) If Assertion is True but the Reason is False. (D) If both Assertion & Reason are false.
1. Assertion :- Most biomolecules which are found in 7. Assertion :- Primary structure of protein is the the acid insoluble fraction are macromolecules. positional information in protein. Reason :- Most biomolecules found in acid insoluble Reason :- Primary structure is determined on the fraction have molecular weight more than 1000 basis of amino acid sequence. Dalton. (1) A (2) B (3) C (4) D (1) A (2) B (3) C (4) D 8. Assertion :- Last amino acid of any protein is 2. Assertion :- Lipids whose molecular weight does known as C-terminal amino acid. not exceed 800 Dalton come under acid insoluble Reason :- Last amino acid of any protein possess fraction. free –COOH group. Reason :- Lipids are present not only as such but (1) A (2) B (3) C (4) D also arranged in structures like membranes during grinding these lipid form vesicle. 9. Assertion :- Metal ions are important for (1) A (2) B (3) C (4) D functioning of cells. Reason :- Metal ions may act as co-factor for 3. Assertion :- Lipids are not strictly macromolecules. several enzymes. Reason :- Molecular weight of lipids does not (1) A (2) B (3) C (4) D exceeds 800 Dalton. 2019-20 (1) A (2) B (3) C (4) D 10. Assertion : Saturated fatty acids are non-essential fatty acids. 4. Assertion :- GLUT-4 is one of the essential protein Reason : They can be synthesized in animal body. for bioenergetics of the cell. (1) A (2) B (3) C (4) D Reason :- GLUT-4 enables glucose transport into cell. 11. Assertion : Maltose is reducing sugar (1) A (2) B (3) C (4) D Reason : In maltose 1–2 glycosidic linkage is present, so free – CHO group present, which is 5. Assertion :- Cellulose is a homopolymer, while responsible for reducing nautre chitin is a heteropolymer. Session(1) A (2) B (3) C (4) D Reason :- Cellulose is made up of identical monomers while chitin is made up of variable 12. Assertion : Glucose is commonest sugar which monomer units. provides energy on hydrolysis. (1) A (2) B (3) C (4) D Reason : Glucose is the precursor of all the types of carbohydrates. 6. Assertion :- TogetherALLEN with polysaccharides and (1) A (2) B (3) C (4) D polypeptides nucleic acids comprise the true macromolecular fraction of any living tissue or cell. 13. Assertion : All monosaccharides are reducing Reason :- Like polysaccharides and polypeptides sugar. nucleic acids also have molecular weight more than Reason : Monosaccharides contain free aldehyde 1000 Dalton. or free ketonic group. (1) A (2) B (3) C (4) D (1) A (2) B (3) C (4) D : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 E 245 P e-Med ca : B g ALLEN 14. Assertion : Sucrose is called invert sugar 19. Assertion : All monosaccharides give Benedict's Reason : Sucrose is initially dextrorotatory but in test. hydrolysed solution mixture is laevorotatory i.e. Reason : All monosaccharide contain free rotation of light is changed aldehyde or ketonic group. (1) A (2) B (3) C (4) D (1) A (2) B (3) C (4) D
15. Assertion : In the oxidation of monosaccharide first 20. Assertion : Phospholipid is a amphipathic step is always phosphorylation. molecule. Reason : All mono saccharide are active with their Reason : Phospholipid contain both hydrophobic phosphate derivatives. and hydrophilic end. (1) A (2) B (3) C (4) D (1) A (2) B (3) C (4) D
16. Assertion : Cholesterol is an important 21. Assertion :- Fructose is a non-reducing sugar biochemical. Reason :- It has a ketonic group Reason : Cholesterol is parental steroid it plays (1) A (2) B (3) C (4) D important role in the synthesis of other biologically 22. Assertion :- Mostly enzymes are made up of active steroid hormones. proteins which have three dimensional structure. (1) A (2) B (3) C (4) D Reason :- Secondary structure of protein are due 17. Assertion : Sucrose is known as invert sugar. to the formation of ionic bonds. Reason : Sucrose is a disaccharide (1) A (2) B (3) C (4) D (1) A (2) B (3) C (4) D 23. Assertion :- Starch can be stained with iodine but 18. Assertion : Phospholipid form bimolecular layer cellulose can not be stained by iodine although both in aqueous medium. are homopolymer of glucose monomers. Reason : Phospholipid molecules are amphoteric. Reason :- Cellulose does not contain complex (1) A (2) B (3) C (4) D helices so can not hold iodine molecules (1) A (2) B 2019-20(3) C (4) D ALLENSession
EXERCISE-IV (A & R ) ANSWER KEY Que. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ans.111141111134111 Que. 16 17 18 19 20 21 22 23 Ans.12311431 : N DE02 B0AI-B0 A GE BI ENG M D LE 2 04-BI M LEC LE 02-E E CI E. 65 246 E