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Wednesday, July 01, 2009


1. Sex hormones are biosynthesized from cholesterol. Which one is the correct sequence
(a) Cholesterol --- Progesterone --- Pregnenolone --- Testosterone --- estradiol
(b) Cholesterol --- Progesterone --- Pregnenolone --- estradiol ---Testosterone
(c) Cholesterol --- Pregnenolone --- Progesterone --- estradiol ---Testosterone
(d) Cholesterol --- Pregnenolone --- Progesterone ---Testosterone --- estradiol

2. Does aminotransferase catalyze the last step in the biosynthesis of Phe ? (a) yes (b) No

3. His is derived from a precursor belonging to the family of (a) α– ketoglutarate
(b) Ribose – 5- phosphate (c) Pyr (d) OAA

4. Arg is derived from a precursor belonging to the family of (a) α– ketoglutarate
(b) Ribose – 5- phosphate (c) Pyr (d) OAA

5. Val is derived from a precursor belonging to the family of (a) α– ketoglutarate
(b) Ribose – 5- phosphate (c) Pyr (d) OAA

6. PRPP contributes ____ carbon atoms in His biosynthesis (a) 6 (b) 5 (c) 3 (d) 4

7. Reactants of the first step in His biosynthesis are (a) PRPP and ATP (b) PRPP and Gln
(c) PRPP and Glu (d) PRPP and Asp

105. The hormone that mediates the action of leptin is (a) epinephrine (b) norepinephrine (c) glucagon ( d) none

8. Somatostatin is released by (a) α cells of Islets of Langerhans (b) β cells of Islets of Langerhans (c) δ cells of Islets of Langerhans

9. Wrong statement about glucagons action is (a) increase is glycogen breakdown (b) decrease in glycogen synthesis (c) increase in F-2,6-BP levels (d) increase in gluconeogenesis

10. The hormone that acts during starvation is (a) glucagon (b) insulin (c) epinephrine (d) none

11. Which of the following hormones is not regulated by hypothalamus ? (a) oxytocin
(b) somatostatin (c) norepinephrine (d) progesterone

12. The site for ibuprofen action is
(a) cyclooxygenase (b) thromboxane synthase (c) lipoxygenase (d) all

13. Aldosterone is released in response to (a) (a) FSH (b) LH (c) Thyrotropin (d) ACTH

14 . Which intermediate is not involved in aminotransferase action ?
(a) aldimine (b) carbanion (c) carbonium ion (d) quinonoid

15. Which of the following statements regarding degradation of ALL amino acids in not true ?

(a) Separation of amino group from the carbon skeleton, ( b) Passage of carbon skeleton to the glucogenic pathway, (c) Excretion of excess amino groups in a form appropriate to the organism and its environment, ( d) Use of amino groups for synthesis of new amino acids or other nitrogenous products.

16. Correct statement for the biosynthesis of phosphatidyl choline in a vertebrate is
(a) First DAG reacts with CDP and then Choline reacts (b) First choline reacts with CDP and then DAG reacts (c) Both (a) and (b) (d) none

17. Correct statement for the biosynthesis of phosphatidyl choline in a bacteria is
(a) First DAG reacts with CDP and then Choline reacts (b) First choline reacts with CDP and then DAG reacts (c) Both (a) and (b) (d) none

18. The hormone that is released from tissues outside brain and interacts with hypothalamus is
(a) Leptin (b) epinephrine (c) glucagon (d) insulin

19. NAD+ participates in the ___ step of biosynthesis of CTP from Asp.
(a) 4th (b) 3rd (c) 2nd (d) 5th

20. CO2 is liberated in the ___ step in biosynthesis of CTP from Asp. (a) 4th (b) 3rd (c) 2nd (d) 5th

21 Gln donates N atoms of positions number ___ of purine ring. (a) one and seven (b) one and nine (c) three and nine (d) seven and nine

22. Asp participates in ____ steps in biosynthesis of AMP from PRPP. (a) 8th and 11th (b) 7th and 12th (c) 6th and 12th (d) 8th and 12th

23. ATP is involved in steps ____ of the biosynthesis of AMP from PRPP. (a) 2, 3, 4, 5
(b) 2, 3, 4, 5, 6 (c) 2, 4, 5, 6 (d) 2, 4, 5, 6, 8

24. Common intermediate in the biosyntheses of aromatic amino acids is
(a) anthranilate (b) shikimate (c) chorismate (d) prephenate

25. Gln participates in ___ step of biosynthesis of Trp from shikimate (a) 5th (b) 4th (c) 6th (7th
77. Number pf hormones released from posterior pituitary is (a) 1 (b) 2 (c) 3 (d) 4

26. Fatty acyl – CoA desaturase is a (a) mixed – function oxidase (b) dioxygenase (c) mixed – function oxygenase (d) acyl – CoA dehydrogenase

27. Methotrexate is a chemotherapeutic agent because it is a competitive inhibitor of
(a) thymidylate synthase (b) dihydrofolate reductase (c) ribonucleotide reductase (d) serine hydroxymethyl transferase

28. Degradation of AMP to uric acid releases (a) O2 (b) CO2 (c) NH3 (d) H2O

29. Common intermediate in the degradation of AMP and GMP to uric acid is
(a) hypoxanthine (b) Xanthine (c) guanine (d) adenine

30. The cofactor of thymidylate synthase is
(a) dihydrofolate (b) methylenetetrahydrofolate (c) tetrahydrofolate (d) SAM

31. Wrong statement about ribonucleotide reductase is (a) It is a dimmer with subunits R1 and R2 (b) dATP is its activator (c) Its active is formed between R1 and R2 (d) Its action involves free radical

32. Wrong statement about ATCase is m(a) ATCase is an allosteric enzyme (b) CTP inhibits it
(c) ATP activates it (d) It catalyzes the first step in the biosynthesis of CTP

33. PRPP participates in the ____step in biosynthesis of CTP from Asp.(a) 4th (b) 3rd (c) 2nd (d) 5th

34. Which of the following actions exerted by epinephrine is not true ? (a) increase in heart rate (b) increase in insulin secretion (c) increase in blood pressure (d) dilation of respiratory passage.

35. Epinephrine is (a) neurotransmitter (b) hormone (c) both neurotransmitter and hormone

36. Which of the following hormones does not involve pituitary gland ? (a) epinephrine (b) oxytocin (c) testosterone (d) prolactin

37. Number of distinct proteins required for biosynthesis of myristic acid from acetyl – CoA is
(a) 9 (b) 8 (c) 7 (d) 10
38. Glyphosate inhibits ________ step in the biosynthesis of shikimate to chorismate
(a) 1st (b) 2nd (c) 3rd (d) 4th

39. The product of chorismate mutase is (a) shikimate (b) phenyl pyruvate (c) prephanate (d ) none

40. For the biosynthesis of Trp N atom is donated by (a) Ser (b) Gly (c) Glu (d)
Ala

41. The neurotransmitter not derived from tyrosine is
(a) serotonin (b) dopamine (c) norepinephrine (d) epinephrine

42. Which is not the substrate of ribonucleotide reductase (a) ADP (b) TDP (c) CDP (d) GDP

43. The substrate of thymidylate synthase is (a) dUMP (b) UMP (c) dUDP (d) dUTP

44. Glycerol can’t be catabolized in which cell

a) Adipose b) Skeletal c) hepatic d) cardiac

45. Lovastatin competitively inbibits HMG-CoA reductase as it structurally resembles

a) HMG b) HMG-CoA c) Mevalonate d) Acetoacetyl CoA

46. High rato of protein to lipid is found in

a) Chylomicrons b) HDL c) VLDL d) LDL

47. Percentage of cholesterol is high in

a) Chylomicrons b) HDL c) VLDL d) LDL

48. Percentage of TAG is high in

a) Chylomicrons b) HDL c) VLDL d) LDL

49. The site of formation of LDL is

a) liver b) intestine c) blood plasma d) All

50. Steroid sensor in SCAP-SREBP complex is

a) SCAP b) SREBP c) Both d) None

51. The primary effect of high intracellular cholesterol

a) inhibition of migration of SCAP-SREBP complex from ER to golgi complex.

b) promotion of migration of SCAP-SREBP complex from ER to golgi complex.

c) proteolytic cleavage of SREBP d) enhanced transcription of HMG-CoA reductase.

52. Which of the following isn’t feature of amino-terminal domain of SREBP

a) it regulates gene transcription. b) it has long half life

c) it promotes uptake and synthesis of cholesterol. d) it is released in cytosol.

53. LDL receptor binds to

a) apoA-I b) apoB-48 c) apo B-100 d) apo C –II

54. By percentage, LDL is rich in

a) protein b) free cholesterol c) cholesterylester d) TAG

55. In receptor-mediated endocytosis of LDL

a) LDL receptor is destroyed by lysosomal enzyme b) LDL receptor is recycled from endosome.

c) LDL receptor is transported from endosome to ER. d) All of the above

56. Which of following protein isn’t associated with HDL

a) ACAT(acyl-CoA cholesterol acyl transferase) b) apo A – I

c) ACAT (lecithin-cholesterol acyl transferase) d) apo C- I

57. Which of following isn’t feature of SR-BI receptor?

a) it mediates endocytosis of HDL in hepatic and steroidogenic tissue

b) it is involved in reverse cholesterol transport

c) it mediates passive movement of cholesterol from cell surface into HDL. d) None

58. Which of the following apolipoprotein triggers uptake of VLDL and chylomicrons remnant in liver.

a) apo D b) apo A- I c) apo E d) apo B-48

59. How many ATPs are required to form one molecule of squalene from mevalonate?

a) 3 b) 6 c) 9 d) 18

60. How many molecules of CO2 is released during formation of 1 molecule of squalene from mevalonate?

a) 1 b) 3 c) 6 d) 5

61. The first cyclic molecule during cholesterol biosynthesis is

a) squalene b) ergosterol c) lanosterol d) stigmasterol

62. Formation of fanesyl phosphate involves

a) head to head condensation b) tail to head condensation c) head to tail condenoation d) tail to tail condensation.

63. Formation of squalene involves.

a) head to head condensation b) tail to head condensation c) head to tail condenoation d) tail to tail condensation.

64. Choline donor during biosynthesis of sphingomyeline is

a) CDP-choline b) CTP-choline c) Phosphatidyl choline d) UDP- choline

65. During biosynthesis of sphingolipids, acyl group transfer occurs in which step

a) 2 b) 3 c) 4 d) 5

66. During biosynthesis of plasmogen, ethanolamine is attached in the form of

a) CDP-ethanolamine b) CTP-ethanolamine c) Unactivate ethanolamine d) Phosphatidyl ethanolamine

67. No. of NADPH used during formation of plasmogen

a) 2 b) 3 c) 4 d) 5

68. Cardiolipin is formed in eukaryotic cell by

a) Condensation of two phosphatidyl glycerol b) Condensation of two phosphatidyl choline

c) Condensation of two phosphatidyl glycerol and CDP-DAG

d) Condensation of two phosphatidyl choline and CDP-DAG.

69. Phosphatidyl serine in mammals is formed by

a) Condensation of CDP-DAG and serine b) Condensation of CDP serine and DAG

c) head groud exchange reaction d) both a and b

70. Inhibition of glyceroneogenis in adipose tissue doesn’t results in:-

a) increase level of free fatty acid in blood b) enhanced glyceroneogenesis in liver

c) increase glycerol level in blood d) none

71. Effect of thiazolidinediones in liver is

a) induction of transcription of PEP carboxykinasic b) Inhibition of transcription of PEP carboxykinasic

c) allosteric activator of PEP carboxykinase d) none

72. Which of following statement is false about TAG cycle?

a) TAG cycle is halted during starvation. b) TAG cycle is apparently futile cycle.

c) TAG cycle maintain free fatty acid in blood d) TAG cycle requires serum albumin and apolipoprotein.

73. Glucocorticoids

a) decreases transcuption of PEPCK in liver. b) increases level of free fatty acid in blood.

c) increases level of glycerol-3-phosphate in adipose d) hinders transport of TAG from liver to adipose tissue.

74. No. of ATPs required to form acyl bonds of 1 molecule of TAG is

a) 3 b) 6 c) 8 d) 10

75. Aspirin inhibits

a) COX-1 b) COX-2 c) both a & b d) none

76. Which of following desaturation doesn’t occurs in mammals

a) ∆9 b) ∆5 c) ∆6 d) ∆12

77. Which of the following isn’t essential fatty acid

a) linoleate b) α-linolenate c) oleate d) all

78. The fatty acid present in low amount in plant cell is

a) 18:0 b) 16:0 c) 18:3 d) 16:3

79. No. of electrons used during formation of stearate from acetyl CoA is

a) 28 b) 32 c) 36 d) 40

80. No. of carbon donated by CO2 during plamitate biosynthesis is

a) 8 b) 4 c) 0 d) 2

81. Phenylbutyrate ingestion enhances biosynthesis of

a) glycine b) glutamine c) glutamate d) alanine

82. PLP forms aldimine linkage with which lysine residue in aminotransferase.

a) Lys255 b) Lys258 c) Lys259 d) Lys260

83. Purely ketogenic amino acid is

a) glycine b) Leucine c) Valine d) Isoleucine

84. Deficiency of Tyrosine amonitransferase cause

a) Tyrosinemia II b) Tyrosinemia I c) Alkaptonuria d) Tyrosinemia III

85. Catabolism of which amino acid involves 1 carbon metabolism

a) Phenylalanine b) Serine c) Luecine d) Lysine

86. Transcription of Urea cycle enzyme increases during

a) carbohydrate rich diet b) protein rich diet c) starvation d) both b & c

87. In reference to urea cycle inhibition of N-acetyl glutamate synthase results in

a) increased urea synthesis b) decrease ATP consumption

c) increased flow of carbon in aspartate arginosucunate pathway d) none

88. Which of the following statement is false about urea cycle?

a) A net of 0.5 ATP used per urea molecule. b) Arginine enhances urea cycle.

c) Urea cycle is dependent of TCA cycle. d) No redox reaction occur in urea cycle.

89. During metabolic acidosis, uptake of which amino acid increases in kidney

a) Glutamate b) Asparagine c) Glutamine d) Alanine

90. Amino acid that involves transamination reaction during catabolism is

a) Serine b) Tryptophan c) Cysteine d) Threonine

91. Which of following fatty acid can gives carbon for gluconeogenesis

a) odd chain FA b) phytic acid c) olecate d) a & b

92. The ratio of oxygen to carbon dioxide in complete oxidation of stearate is

a) 23:18 b) 24:18 c) 26:18 d) 28:18

93. Not true about mammalian fatty acid synthase is

a) fatty acid synthase occur in cytosol. b) fatty acid synthase is a single polypeptide

c) all seven active site act as enzyme d) AT transfers acyl group from ACP to KS.

94. Apolipoprotein isn't involved in :

a) Acting as ligand for capillary lipases b) decreasing the density of chylomicrons

c) enhancing the solubility of chylomicrons in blood. d) stabilizing chylomicrons.

95. Ammonia toxicity isn't associated with :

a) Cerebral edema b) low level of ATPs c) increased level of GABA d) inhibition of TCA cycle.

96. which of the following enzyme is found only in liver mitochondrial matrix:

a) Thiolase b) HMG-CoA synthase c) HMG- CoA lyase d) malate dehrdrogenase.

97. Carbohydrate isn't used for energy storage instead of TAG because:

a) Carbon in carbohydrate is more oxidized than carbon in fatty acids.

b) hydration of carbohydrate is problematic during storage and transportation.

c) Carbohydrate would increase osmolarity of cytosol. d) All of above.

98. Excess of benzoate intake increases the de novo biosynthesis of

a) glutamine b) Glutamate c) Valine d) Glycine

99. Fatty acids aren't primarily biosynthesized in plant and bacteria for:

a) Maintainence of membrane fluidity b) Storage of energy c) Formation of signal molecules d) None of the above

100. beta- oxidation is not favoured by:

a) low conc. of acetyl CoA b) Enhanced activity of acetyl CoA carboxylase

c) high [NAD] / [NADH] ratio d) high level of ephinephrine and glucagon

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