MCQ Bio-Chemistry. Bio-Chemistry . Prof, Bun Seangkhin
1. Which of the following sugars is absorbed by facilitated transport? a. Galactose b. Fructose c. Xylose d. Glucose e. Arabinose 2. Amylase present in saliva is: a. α-amylase α-amylase b. β-amylase β-amylase c. γ-amylase γ-amylase d. All of the above e. None of the above 3. The absorption of glucose is decreased by the deficiency of: a. Vitamin A b. Vitamin D c. Thiamine d. Vitamin B12 e. Folic acid 4. For activity of salivary amylase. Which of the following is required as activator: – a. HCO3 ion b. Presence of Na+ c. Presence of K+ d. Chloride ion e. None of the above 5. Which of the following hormone increases the absorption of glucose from GI tract? a. Insulin b. Thyroid hormones c. Glucagon d. FSH e. LH 6. UDP – Glucose Glucose is converted to UDP – glucuronic glucuronic acid by: a. ATP b. GTP c. NADP+ d. NAD+ e. FAD 7. All of the following compounds are intermediates of TCA cycle except: a. Malate b. Pyruvate c. Oxaloacetate d. Fumarate e. Succinate 8. In conversion of lactic acid to glucose, three reactions of glycolytic pathway are circumvented, which of the following enzymes do not participate? a. Pyruvate carboxylase b. Phosphoenolpy Phosphoenolpyruvate ruvate carboxykinase c. Pyruvate kinase d. Glucose-6-pho Glucose-6-phosphatase sphatase e. Fructose-1, 6-biphosphatase 9. MacArdle‟s disease involves a deficiency of the which enzyme? a. Acid maltase b. Glucose-6-pho Glucose-6-phosphatase sphatase c. Hepatic phosphorylase d. Muscle phosphoryl phosphorylase ase e. Branching enzyme 10. In the normal resting state of humans, most of the blood glucose burnt as „fuel‟ is consumed by: a. Liver b. Brain c. Kidneys d. Adipose tissue e. Muscles 11. A regulator of the enzyme gl ycoge ycogen n synt ynth h as ase e is: a. Citric acid b. 2,3-biphospho 2,3-biphosphoglycerate glycerate (2,3-BPG) c. Pyruvate d. GTP e. Glucose-6-PO4
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12. Which of the following compound is a positive allosteric modifier of the enzyme pyruvate carboxylase? a. Biotin b. Acetyl-CoA c. Oxaloacetate d. ATP e. Fructose-6-P 13. A specific inhibitor for succi nate dehydr ogenase is: a. Arsenite b. Malonate c. Citrate d. Cyanide e. Fluoride 14. Most of metabolic pathways are either anabolic (synthetic) or catabolic (degradation). Which of the following pathways is considered as “amphibolic” in nature? a. Glycogenesis b. Glycolytic pathway c. Lipolysis d. Citric acid cycle e. Glycogenolysis 15. Transketolase activity is affected in: a. Biotin deficiency b. Pyridoxine deficiency c. PABA deficiency d. Thiamine deficiency e. Manganese deficiency 16. The following metabolic abnormalities occur in Diabetes mellitus, except: a. Increase plasma FFA b. Increased pyruvate carboxylase activity c. Decrease lipogenesis d. Decrease gluconeogenesis e. Increase PEP – carboxykinase activity 17. A substance that is not an intermediate in the formation of D-glucuronic acid from glucose is: a. Glucose-1-P b. 6-phosphogluconate c. Glucose-6-P d. UDP – Glucose e. UDP – glucuronate 18. Von Gierke‟s disease is characterised by a deficiency of which enzyme? a. Glucokinase b. Glucose-6-phosphatase c. α-1, 6-glucosidase d. Glycogen synthase e. De-branching enzyme 19. The hydrolysis of glucose-6-P is catalysed by a phosphatase that is not found in which of the following? a. Liver b. Kidney c. Muscle d. Small intestine e. None of the above 20. An essential for converting glucose to glycogen in Liver is a. Lactic acid b. GTP c. CTP d. UTP e. Pyruvic acid 21. Which of the following is a substrate for aldolase activity in glycolytic pathway? a. Glyceraldehyde-3-P b. Glucose-6-P c. Fructose-6-P d. 1,3-diphosphoglycerate e. Fructose-1,6-bi-P 22. Which of the following hormones is not involved in carbohydrate metabolism: a. Cortisol b. ACTH c. Glucagon d. Vasopressin e. Growth hormone
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23. Dehydrogenases involved in HMP shunt are specific for: a. NADP+ b. NAD+ c. FAD d. FMN e. None of the above 24. Which of the following enzymes in glycolytic pathway is inhibited by fluoride? a. Glyceraldehyde 3-P-dehydrogenase b. Phosphoglycreate kinase c. Pyruvate kinase d. Enolase e. Aldolase 25. “Micelles” formed in the intestine have which of the following properties? ` a. They are absorbed intact in the duodenun b. They contain mostly triacylglycerol (TG) c. They facilitate transfer of hydrolytic products of TG to intestinal mucosal cell d. They are secreted by cells lining the intestine e. They are mainly absorbed from stomach wall 26. Dietary TGs (triacylglycerols) are absorbed from the intestinal lumen after hydrolysis mainly as: a. Fatty acids and glycerol b. Fatty acids and two monoacylglycerol c. Fatty acids and α, β-diglyceride d. Acyl-CoA and glycerol e. Glycerol-phosphate and fatty acids 27. The gastric lipase is inactive because of the following reasons except: a. No emulsifications of fats take place in stomach b. The enzyme is secreted in small quantity c. pH of gastric juice is not conducive for its action d. The gastric juice is highly acidic e. The conc. of bile salts is high in gastric juice 28. Delay in the rate of gastric emptying is due to the action of: a. Pancreozymin b. Enterokinase c. Enterogastrone d. CCK e. Gastric lipase 29. Ca++ facilitates action of lipase: a. By emulsification b. By inhibiting emulsification c. By soap formation d. By formation of micelle e. By formation of tiny droplets 30. A pathway that requires NADPH as a cofactor is: a. Fatty acid oxidation b. Extramitochondrial de novo fatty acid synthesis c. Ketone bodies formation d. Glycogenesis e. Gluconeogenesis 31. The „committed step‟ in the biosynthesis of cholesterol from acetyl-CoA is: a. Formation of acetoacetyl-CoA from acetyl-CoA b. Formation of mevalonate from HMG-CoA c. Formation of HMG-CoA from acetyl-CoA and acetoacetyl-CoA d. Formation of squalene by squalene synthetase e. Formation of lanosterol from squalene by cyclisation.
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32. The most important source of reducing equivalents for FA synthesis in the Liver is: a. Glycolysis b. HMP-shunt c. TCA cycle d. Uronic acid pathway e. Gluconeogenesis 33. All of the following tissues are capable of using ketone bodies, except: a. Brain b. Renal cortex c. Red blood cells d. Cardiac muscle e. Skeletal muscle 34. Ketone bodies are synthesised from fatty acid oxidation products by which of the following organs? a. Skeletal muscles b. Kidney c. Erythrocytes d. Brain e. Liver 35. Which of the following cofactors of their derivatives must be present for the conversion of acetyl-CoA to Malonyl-CoA in extramitochondrial FA synthesis? a. FAD b. FMN c. ACP d. NAD+ e. Biotin 36. All statements regarding 3-OH-3 methly glutaryl CoA are true, except: a. It is formed in the cytoplasm b. Required in ketogenesis c. Involved in synthesis of FA d. An intermediate in cholesterol biosynthesis e. Enzyme involved in HMG-CoA synthase 37. Which of the following lipoproteins would contribute to a measurement of plasma cholesterol in a normal individual following a 12 hour fast? a. Chylomicrons b. VLDL c. Both VLDL and LDL d. LDL e. Both chylomicrons and LDL 38. All statements regarding ketone bodies are true except: a. They may result from starvation b. They are formed in kidneys c. They include acetoacetic acid and acetone d. They may be excreted in urine e. They are present in high concentration in uncontrolled Diabetes mellitus 39. Brown adipose tissue is characterised by the following: a. Present in large quantities in adult humans b. Mitochondrial content higher than white adipose tissue c. Oxidation and phosphorylation are tightly coupled d. Absent in hibernating animals e. All of the above 40. Ketosis is partly ascribed to: a. Over production of glucose b. Under production of glucose c. Increased carbohydrate utilization d. Increased fat utilisation e. Increased pyruvate in liver 41. Triacyl glycerol (TG) Present in VLDL is hydrolysed by: a. Intestinal lipase b. Lipoprotein lipase c. Hormone sensitive TG lipase d. Pancreatic lipase e. Co-lipase 42. Carnitine is synthesised from: a. Lysine b. Serine c. Choline d. Arginine e. Threonine Biochemistry, BM21
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43. A metabolite which is common to pathways of cholesterol biosynthesis from acetylCoA and cholecaliferol formation from cholesterol is: a. Zymosterol b. Lumisterol c. Ergosterol d. 7-Dehydrocholesterol e. Pregnenolone 44. Acetyl-CoA required for extramitochondrial FA synthesis is produced by: a. Pyruvate dehydrogenase complete b. Thiolase c. Acetyl-CoA synthase d. Carnitine-acyl tranferase e. Citrate Lyase 45. Biosynthesis of TG and lecithin both require an intermediate a. Monoacyl glycero-(P) b. Phosphatidic acid c. Phosphatidyl ethanolamine d. Phosphatidly cytidylate e. Phosphatidyl adenylate 46. The rate limiting step in cholesterol biosynthesis is: a. Squalene synthetase b. Mevalonate kinase c. HMG-CoA synthetase d. HMG-CoA reductase e. Thiolase 47. Pancreatic juice contains all of the following, except: a. Trypsinogen b. Lipase c. Cholecystokinin d. Chymotrypsinogen e. Amylase 48. The milk protein in the stomach in an adult is digested by: a. Pepsin b. Rennin c. HCI d. Trypsin e. Chymotrypsinogen 49. Carboxypeptidase A enzyme of pancreatic juice contains: a. Copper b. Zinc c. Magnesium d. Manganese e. Cobalt 50. The enzyme collagenase of pancreatic juice hydrolyses collagen present in: a. Milk b. Eggs c. Cereals d. Meat e. Soyabeans 51. The zymogen form trypsinogen of pancreatic juice is converted to „active‟ trypsin by: a. Pepsin b. Enterocrinin c. Enterokinase d. Rennin e. Gastrin 52. Which of the following regarding digestion of proteins are correct, except: a. Pepsinogen is activated by autoactivation (pH-2) or autocatalysis b. The major products or protein hydrolysis are large petides and some free amino acids c. Most of the digested proteins are absorbed in the intestine in the form of polypeptides d. Trypsin and chymotrypsin are secreted by the pancreas as inactive zymogens e. Enterokinase activates pancreatic trypsinogen 53. Rennin acts on casein of milk in infants in presence of: a. Mg++ b. Zn++ c. Co++ d. Ca++ e. Mn++
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54. During intestinal proteolysis: a. Enterokinase converts trypsinogen to trypsin b. Involves conformational change, but no change in covalent structure c. Trypsin activates procarboxypeptidase A and proelastase d. a + b true e. a + c true 55. Pepsin contains large amounts of which of the following amino acids: a. Aromatic amino acids b. Acidic amino acids c. Basic amino acids d. Sulphur containing amino acids e. Neutral amino acids 56. D -amino acids are absorbed by: a. Active transport b. In presence of a ‘carrier’ molecule c. In presence of sodium ions d. Passive diffusion e. None of the above 57. Chymotrypsin hydrolyses the peptide linkages containing a. Phenyl alanine and tyrosine b. Phenyl alanine and lysine c. Tyrosine and lysine d. Tyrosine and leucine e. Phenylalanine and leucine 58. Quantitatively the most important enzyme involved in formation of NH3 from amino acids in humans is: a. L-amino acid oxidase b. Serine dehydratase c. Glutamate dehydrogenase d. Histidase e. Desulfhydrase 59. The two nitrogen atoms in urea arise from: a. Ammonia and glutamine b. Glutamine and aspartic acid c. Glutamine and glutamic acid d. Ammonia and aspartic acid e. Glutamine and alanine 60. A product of the series of reactions that converts carbamoyl-(P) to urea is: a. Arginine b. Citrulline c. Fumarate d. Aspartate e. Adenosine triphosphate 61. Ornithine has all of the following properties except: a. It is an intermediate of urea cycle b. It is not found in proteins c. It is glucogenic d. It can be formed from arginine e. It is a mono-amino mono-carboxylic acid 62. Epinephrine is formed from norepinephrine by: a. Hydroxylation b. Oxidative deamination c. Decarboxylation d. N-methylation e. O-methylation 63. The rate limiting step in the biosynthetic pathway of catecholamines is: a. The hydroxylation of phenylalanine b. The hydroxylation of tyrosine c. The reduction of biopterine d. The formation of dopamine e. None of the above 64. Which of the following compounds serve as a primary link between the TCA cycle and the urea cycle? a. Malate b. Citrate c. Oxaloacetate d. Fumarate e. Succinate Biochemistry, BM21
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65. Serine can be a percussor of each of the following, except: a. Cysteine b. Methionine c. Ethanolamine d. Glycine e. Choline 66. The rate of excretion of certain substances in 24-hr sample of urine can be used to estimate the rate of muscle protein loss. Which of the following substances falls into this category? a. Ammonia b. Urea c. Uric acid d. 3-Methyl histidine e. Ergothioneine 67. Tryptophan is best described by which of the following statement? a. It produces thyroid hormones b. Is a precursor for melanin c. It is a precursor of the pineal hormone melatonin d. It produces catecholamines e. It is glucogenic only 68. Which of the following amino acids are required for synthesis of creatine? a. Arginine, Asp, 'active' methionine b. Arginine, glycine 'active' methionine c. Arginine, lysine, methionine d. Glycine, Asp, ornithine e. Arginine, glutamic acid, 'active' methionine 69. The following statements regarding creatinine are correct except: a. Blood levels of creatinine is a good indicator of kidney function b. Although 24-hr excretion rate is very constant, there is a marked diurnal variation c. Urinary creatinine levels give a measure of muscle mass d. Excretion of creatinine is urine of adults is very constant from day-to-day e. Cratinine is an anhydride of creatine-(P) 70. Which of the following amino acids on degradation produces a glucogenic intermediate of TCA cycle and ketone body? a. Glycin b. Phenylalanine c. Alanine d. Cysteine e. Serine 71. Reactions of urea cycle take place in liver cells a. In cytosol b. Only in lysosomes c. In mitochondrial matrix d. Both cytosol and mitochondrial matrix. e. Both cytosol and lysosomes 72. Breakdown of amino acid tryptophan begins with formation of: a. Urocanic acid b. Nicotinic acid c. Anthranilic acid d. N-formyl kynurenine e. None of the above 73. Urinary oxalates in small quantities may arise from: a. Tyrosine b. Glycine c. Serine d. Citrates e. Oxaloacetate 74. A high ATP/AMP ratio will inhibit which of the following enzyme? a. Glyceraldehyde-3-P dehydrogenase b. Pyruvate kinase c. Enolase d. Phosphofructokinase e. Glucose-6-P dehydrogenase
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Reference https://books.google.com.kh/books?id=I3gC0bX_IKAC&pg=PA323&lpg=PA323&dq#v onepage&q&f=false Answers researched by Hul Vichhai Textbook of Medical Biochemistry ,
1-2 page 6-24 page 30-31 page 39-46 page 58-69 page 74 page
323 389-390 460 462 529 534
=
By M. N. Chatterjea, Rana Shinde
3-5 25-29 32-38 47-57 70-73
page page page page page
324 397 461 469 530
God Bless you abundantly. Dieu te bénisse abondamment.
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