EXAM NUMBER:______
SEAT NUMBER______
NAME______
DABC 711 - HUMAN BIOCHEMISTRY EXAMINATION NO. 2 INSTRUCTIONS
1. Write your name on the front of the exam and on the answer sheet.
2. The exam contains 52 multiple choice question. Read each question carefully before answering. Choose the best choice from each multiple choice question and record your answer on the answer sheet using a #2 pencil. The multiple choice pquestions are worth two (2) points each. Points will not be given for a correct multiple choice answer on the exam but an incorrect answer on the answer sheet. Questions for the case study are the last questions on the exam.
3. This exam is worth 100 points (although 104 is possible).
4. Use your time wisely. All exams will be collected at 8:55 A.M.
5. GOOD LUCK ! (1) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
1. Consider statements 1 and 2. 1. Most nucleotides used in human systems are not absorbed from the diet. 2. A nucleoside is bigger than a nucleotide.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
2. (1) are the main precursors in the de novo synthesis of (2) .
A. (1) Amino acids; (2) purines B. (1) Amino acids; (2) pyrimidines C. (1) Amino acids; (2) both purines and pyrimidines D. (1) Carbohydrates; (2) purines E. (1) Carbohydrates; (2) pyrimidines
3. PRPP is
A. an enzyme used in purine synthesis. B. an enzyme used in pyrimidine synthesis. C. a carbohydrate phosphate used in nucleotide salvage. D. used to recover nucleotides from the diet. E. activated by GTP.
4. Gout
1. is the result of a high amount of urea in the individual. 2. is the result of a high concentration of urate in the individual. 3. can be caused by an excessive breakdown of pyrimidine nucleotides. 4. can be a secondary consequence of increased cell destruction.
A. Only 1 B. Only 2 C. 1 and 3 D. 2 and 4 E. 2, 3 and 4
5. Which of the following diphosphate deoxyribonucleotides are not made directly from thioredoxin reduction?
1. dADP 2. dTDP 3. dGDP 4. dUDP 5. dCDP
A. 1 and 2 B. 2 and 4 C. 3 and 5 D. 1, 3 and 5 E. 2, 3 and 4
(2) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
6. Consider statements 1 and 2. 1. A high concentration of dGTP can stimulate production of dATP. 2. Some anticancer drugs inhibit the regeneration of tetrahydrofolate, which in turn directly affects DNA synthesis.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
7. Restriction enzymes are used
A. to cleave single-stranded DNA. B. to cleave double-stranded DNA. C. to link nucleotides in PCR. D. as exonucleases. E. to cleave RNA.
8. A radioactively labeled DNA probe is used to determine a species of bacteria in a periodontal infection. What is the step immediately preceding addition of the probe?
A. Southern blotting B. electrophoresis C. autoradiography D. Northern Blotting E. enzyme cleavage
9. Why is use of a DNA probe a viable method to determine a species of bacteria in a periodontal infection?
A. Aerobic bacteria are not easily culturable, and are thus difficult to identify. B. Anaerobic bacteria are not easily culturable, and are thus difficult to identify. C. It costs less to use a DNA probe than to culture bacteria. D. It is easier to do the procedure with a DNA probe than to culture the bacteria.
10. What is the last step in the Cohesive-end Method?
A. Use of ligase B. Use of restriction enzyme C. Attach nucleotide ends D. Clone nucleotide ends E. Attach antibiotic nucleotide ends
11. DNA chips containing oligonucleotide arrays are capable of
A. synthesizing large nucleotide strands. B. synthesizing oligonucleotides (less than 15 nucleotides). C. sequencing large nucleotide strands. D. sequencing oligonucleotides (less than 15 nucleotides).
(3) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
12. Assume that you want to clone the proinsulin gene in E. coli bacteria. Which of the following would be the most important to your success?
A. Use cDNA B. Use a DNA probe C. Make sure your vector has tetracycline resistance D. Use viruses as vectors E. Use plasmids as vectors
13. Consider statements 1 and 2. 1. PCR technique is utilized to synthesize multiple copies of a DNA fragment. 2. Chromosome walking can be used to determine the nucleotide sequence of a long piece of DNA via use of the Cohesive-end method.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
14. The protein, proinsulin, is cloned in procaryotes (rather than insulin) because procaryotes do not have the
A. ability to do read exons. B. enzymes to add carbohydrates to proinsulin to make insulin. C. enzymes to cleave proinsulin to insulin. D. ability to make a simple protein via cloning. E. ability to do chromosome walking.
15. Which of the following is false?
1. A single correct nucleotide sequence can be determined from an amino acid sequence. 2. A single correct amino acid sequence can be determined from an exon nucleotide sequence. 3. Plasmids can affect more bacterial cells than viruses.
A. Only 1 B. Only 2 C. 1 and 2 D. 1 and 3 E. 1, 2 and 3
16. Consider statements 1 and 2 concerning recombinant technology in eucaryotic cells. 1. Both introns and exons are read and converted into RNA. 2. Posttranslational modifications can be carried out inside these cells.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
(4) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
17. Which of the following is not a sign of the inflammatory response?
A. rubor B. dolor C. tumor D. calor E. halor
18. In inflammation, PMNs are
A. complement B. prostaglandins C. leukotrienes D. white blood cells E. immunoglobulins
19. Which of the following events in inflammation will occur following opsonization?
A. Chemotaxis and Diapedesis B. Phagocytosis and Margination C. Diapedesis and Margination D. Degranulation and Chemotaxis E. Degranulation and Phagocytosis
20. There is usually a (1) amount of pain associated with acute inflammation in the dental pulp (compared to a surface cut) because (2) .
A. (1) higher; (2) exuded fluid produces more pressure in a confined space B. (1) higher; (2) sensory nerve endings are more sensitive internally than externally C. (1) lower; (2) exuded fluid produces less pressure in a confined space D. (1) lower; (2) sensory nerve endings are less sensitive internally than externally
21. Rank the following occurrences in the grafting process from day 0 to day 8 .
1. organic union 2. plasma circulation 3. vascularization
A. 1, 2, 3 B. 2, 1, 3 C. 3, 1, 2 D. 2, 3, 1 E. 3, 2, 1
22. What is the best sequence of events in wound healing?
1. Wound contraction 2. Epithelization 3. Clot formation 4. Granulation tissue formation
A. 3, 1, 2, 4 B. 1, 3, 4, 2 C. 4, 1, 3, 2 D. 1, 3, 2, 4 E. 3, 2, 4, 1 (5) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
23. Which one of the following occurs with edema in inflammation?
1. Provides nutrients for cells 2. Inactivates toxin in fluid using proteolytic enzymes 3. Contains complement proteins
A. Only 1 B. Only 2 C. 1 and 2 D. 2 and 3 E. 1, 2 and 3
24. Consider statements 1 and 2. 1. Capillary budding is when epithelial cells branch out to seal a wound. 2. Inflammation is included as part of the repair process in wound healing.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
25. What is the normal pressure in the pulp of the tooth?
A. About 5 mm Hg B. About 10 mm Hg C. About 20 mm Hg D. About 30 mm Hg E. About 40 mm Hg
26. NSAIDs (NonSteroidal AntiInflammatory Drugs) like aspirin and Ibuprofen are taken to prevent synthesis of
A. prostaglandins B. kinins C. complement D. platelets E. monocytes
27. Which of the following killing agents of bacteria are not oxygen dependent?
1. lactoferrin 2. lactic acid 3. superoxide anion 4. hydrogen peroxide
A. 1 and 2 B. 3 and 4 C. 2, 3 and 4 D. 2, 3 and 4 E. 1, 2, 3 and 4
(6) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
28. Which of the following is most capable of regeneration?
A. Kidney B. Muscle C. Heart D. Brain E. Liver
29. Histamine binds to receptor sites on endothelial cells, causing (1) . This action in turn, causes (2) , resulting in vascular permeability.
A. (1) cell contraction; (2) intercellular gaps B. (1) cell contraction; (2) activation of cellular channels C. (1) cell expansion; (2) intercellular gaps D. (1) cell expansion; (2) activation of cellular channels
30. In reversible pulpitis, (1) are responsible for the pain in cold sensitivity. In a case of tooth trauma, where the blood supply is cut off to the tooth, (2) are not the cause of the resulting pain.
A. (1) A-delta fibers; (2) C fibers B. (1) A-delta fibers; (2) A-delta fibers C. (1) C fibers; (2) C fibers D. (1) C fibers; (2) A-delta fibers
31. Consider statements 1 and 2. 1. Surgical removal of the complete pulp is called a pulpotomy. 2. Antibiotics should be prescribed for infection and inflammation.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
32. Which of the following is (are) true?
1. Fluoride is incorporated both systemically and topically in teeth. 2. In blood, most fluoride is bound to protein. 3. Fluoride is absorbed only in the small intestine.
A. Only 1 B. Only 2 C. Only 3 D. 1 and 2 E. 2 and 3
33. Consider statements 1 and 2. 1. There is a larger concentration of fluoride at the DEJ than the average concentration of fluoride in dentin. 2. There is a larger concentration of fluoride in teas than in most other drinks.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false. (7) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
34. From highest to lowest, rank the levels of fluoride in the following
1. Dentin 2. Enamel 3. Cementum 4. Bone
A. 4, 1, 3, 2 B. 3, 1, 2, 4 C. 3, 4, 1, 2 D. 1, 2, 3, 4 E. 4, 2, 3, 1
35. Which of the following are true?
1. Fluoride can inhibit carbohydrate metabolism in oral microorganisms. 2. The Ca-OH bond is shorter than the Ca-F bond. 3. Fluoroapatite is more insoluble than hydroxyapatite.
A. Only 1 B. Only 2 C. 1 and 2 D. 1 and 3 E. 1, 2 and 3
36. THC binds to (1) receptors in the brain. These receptors are classified as (2) receptors.
A. (1) CB1; (2) opioid B. (1) CB1; (2) G-protein C. (1) CB2; (2) opioid D. (1) CB2; (2) G-protein
37. From highest to lowest, rank the strengths of the following amphetamines.
1. Dexamphetamine 2. Benzedrine 3. Methamphetamine
A. 1, 2, 3 B. 2, 3, 1 C. 2, 1, 3 D. 3, 2, 1 E. 3, 1, 2
38. For which of the following conditions would you not use an amphetamine?
A. nasal congestion B. narcolepsy C. high blood pressure D. weight control
(8) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
39. Consider statements 1 and 2. 1. Crack cocaine is usually taken nasally (snorted). 2. The liver can detoxify cocaine more efficiently than amphetamines.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.
40. Which of the following occur in both the mitochondria and the cytoplasm?
1. gluconeogenesis 2. citric acid cycle 3. urea cycle 4. glycolysis
A. Only 1 B. Only 2 C. 1 and 3 D. 2 and 4 E. None of the above
41. Which system is the least involved in organ communication?
A. vascular B. respiratory C. endocrine D. nervous
42. Most CO2 in the body is initially produced via
A. electron transport. B. gluconeogenesis in the liver. C. carbonic acid synthesis. D. bicarbonate buffer synthesis. E. TCA cycle.
Questions 43-52 concern the Case Study (See last page on the exam for reference.)
43. What is the normal RBC count in infants?
A. 2.5 - 4.0 million/mm3 B. 4.0 - 5.5 million/mm3 C. 5.5 - 7.0 million/mm3 D. 7.5 - 9.0 million/mm3
44. Why was the marrow hypercellular?
A. Inflammation in the unfant dictated the production of more platelets B. Inflammation in the unfant dictated the production of moreWBCs C. Inflammation in the unfant dictated the production of more RBCs D. The body was trying to overcome the deficiency of correct RBCs produced E. The body was trying to overcome the deficiency of correct WBCs produced
(9) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
45. What does Vitamin B12 have to do with pernicious anemia?
A. Vitamin B12B is needed for enzyme synthesis
B. Vitamin B12B is needed for production of Intrinsic Factor
C. Vitamin B12B is needed to regenerate tetrahydrofolate for RBC synthesis
D. Vitamin B12B is needed to provide iron for RBC synthesis
E. Vitamin B12B is needed to transport glucose in RBC synthesis
46. What is the biochemical role of folic acid in treating the anemia?
A. Folic acid is involved in transamination reactions of amino acids B. Folic acid is involved in transamination reactions of nucleic acids C. Folic acid is involved in oxidation-reduction reactions of amino acids D. Folic acid is involved in the one-carbon pool in the synthesis of amino acids E. Folic acid is involved in the one-carbon pool in the synthesis of nucleotides
47. What is the probable cause of the high levels of orotic acid excretion?
A. Enzyme defect such that PRPP cannot be attached to orotic acid B. Anemia causing breakdown of excess amount of nucleotides C. Lack of salvage such that orotic acid accumulates D. Enzyme amplification such that synthesis of orotic acid is accelerated E. Excess purine degradation causing excess orotic acid accumulation
48. Why was treatment of uridylic and cytidylic acids effective?
1. Nucleotides provided feedback inhibited production of orotic acid 2. Sufficient DNA could be synthesized 3. Nucleosides provided were sufficient to correct enzyme defect
A. Only 1 B. Only 2 C. 1 and 2 D. 2 and 3 E. 1, 2 and 3
49. Why was treatment of uracil less effective?
A. Uracil conversion to nucleotide still required PRPP interaction B. Uracil is not absorbed as well as a purine (compared to uridylic acid) C. Uracil is not absorbed as well as a pyrimidine (compared to uridylic acid) D. Cytosine was still deficient in the system E. Cytidylic acid cannot be made from uracil
50. What is prednisolone?
A. A prostaglandin B. A leukotriene C. A complement protein D. An adrenal corticosteroid E. A mineral corticosteroid
(10) DABC 711 - HUMAN BIOCHEMISTRY February 28, 2003
51. Why was diarrhea induced by the high-salt and high-phosphate content of the nucleotide preparation?
A. Acids tend to draw water B. Lack of folic acid will cause diarrhea C. Lack of Vitamin B12 will cause diarrhea D. Phosphates tend to attract water E. High osmotic concentrations tend to draw water
52. Consider statements 1 and 2 involving the relationship between anemia and the high levels of orotic acid excretion. 1. High levels of orotic acid excretion mean less synthesis of DNA. 2. RBCs have a relatively short life span, so they need to be constantly synthesized.
A. Statement 1 is true and Statement 2 is false. B. Statement 1 is false and Statement 2 is true. C. Both statements are true. D. Both statements are false.