bio-chemistry mcq - no answer

7/21/2019 Bio-Chemistry MCQ - No Answer

1/8Biochemistry, BM21 10 March 2015 Page 1

MCQ 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. -amylase b. -amylase

c. -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. HCO3ion 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 glucosefrom GI tract?

a. Insulin b. Thyroid hormonesc. Glucagon d. FSH e. LH

6.UDPGlucose is converted to UDPglucuronic acid by:a. ATP b. GTPc. 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. Phosphoenolpyruvate carboxykinasec. Pyruvate kinase d. Glucose-6-phosphatase

e. Fructose-1, 6-biphosphatase

9.MacArdles disease involves a deficiency of the which enzyme?a. Acid maltase b. Glucose-6-phosphatasec. Hepatic phosphorylase d. Muscle phosphorylase

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. Brainc. Kidneys d. Adipose tissue e. Muscles

11.A regulator of the enzyme glycogen synthase is:a. Citric acid b. 2,3-biphosphoglycerate (2,3-BPG)

c. Pyruvate d. GTP e. Glucose-6-PO4


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Biochemistry, BM21 10 March 2015 Page 2

12.Which of the following compound is a positive allostericmodifier of the enzyme pyruvate carboxylase?a. Biotin b. Acetyl-CoAc. Oxaloacetate d. ATP e. Fructose-6-P

13.A specific inhibitor for succinate dehydrogenase is:a. Arsenite b. Malonatec. 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 activityc. Decrease lipogenesis d. Decrease gluconeogenesis

e. Increase PEPcarboxykinase activity

17.A substance that is not an intermediate in the formation of D-glucuronic acid fromglucose is:a. Glucose-1-P b. 6-phosphogluconate

c. Glucose-6-P d. UDPGlucose e. UDPglucuronate

18.Von Gierkes disease is characterised by a deficiency ofwhich enzyme?a. Glucokinase b. Glucose-6-phosphatase

c. -1, 6-glucosidase d. Glycogen synthase e. De-branching enzyme19.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 isa. Lactic acid b. GTPc. 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-Pc. 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. ACTHc. 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 isinhibited by fluoride?a. Glyceraldehyde 3-P-dehydrogenase b. Phosphoglycreate kinasec. 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 afterhydrolysis mainly as:

a. Fatty acids and glycerol b. Fatty acids and two monoacylglycerol

c. Fatty acids and , -diglyceride d. Acyl-CoA and glycerole. 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 quantityc. pH of gastric juice is not conducive for its action

d. The gastric juice is highly acidice. 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. Enterokinasec. 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 fromacetyl-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-CoAd. 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 thefollowing 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 theconversion 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 biosynthesise. Enzyme involved in HMG-CoA synthase

37. Which of the following lipoproteins would contribute to a measurement of plasmacholesterol 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 mellitus39. Brown adipose tissue is characterised by the following:

a. Present in large quantities in adult humansb. Mitochondrial content higher than white adipose tissue

c. Oxidation and phosphorylation are tightly coupledd. 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 utilisatione. 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


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43. A metabolite which is common to pathways of cholesterol biosynthesis from acetyl-CoA and cholecaliferol formation from cholesterol is:a. Zymosterol b. Lumisterolc. Ergosterol d. 7-Dehydrocholesterol e. Pregnenolone

44.Acetyl-CoA required for extramitochondrial FA synthesis is produced by:a. Pyruvate dehydrogenase complete b. Thiolasec. Acetyl-CoA synthase d. Carnitine-acyl tranferase e. Citrate Lyase

45.

Biosynthesis of TG and lecithin both require an intermediatea. 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 kinasec. HMG-CoA synthetase d. HMG-CoA reductase e. Thiolase

47. Pancreatic juice contains all of the following, except:a. Trypsinogen b. Lipasec. 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. Eggsc. Cereals d. Meat e. Soyabeans

51.

The zymogen form trypsinogen of pancreatic juice is converted to active trypsin

by:a. Pepsin b. Enterocrininc. 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 autocatalysisb. 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 trypsinogen53.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 structurec. Trypsin activates procarboxypeptidase A and proelastase

d. a + b truee. a + c true

55. Pepsin contains large amounts of which of the following amino acids:a. Aromatic amino acids b. Acidic amino acidsc. 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 containinga. 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 dehydratasec. 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 acide. Glutamine and alanine

60.A product of the series of reactions that converts carbamoyl-(P) to urea is:

a. Arginine b. Citrullinec. 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 argininee. 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 dopaminee. None of the above

64. Which of the following compounds serve as a primary link between the TCA cycleand the urea cycle?a. Malate b. Citrate

c. Oxaloacetate d. Fumarate e. Succinate


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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 toestimate 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 melaninc. 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 variationc. Urinary creatinine levels give a measure of muscle mass

d. Excretion of creatinine is urine of adults is very constant from day-to-daye. Cratinine is an anhydride of creatine-(P)

70.Which of the following amino acids on degradation produces a glucogenicintermediate of TCA cycle and ketone body?a. Glycin b. Phenylalanine

c. Alanine d. Cysteine e. Serine71.Reactions of urea cycle take place in liver cells

a. In cytosol b. Only in lysosomesc. 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 acidc. Anthranilic acid d. N-formyl kynurenine e. None of the above

73.Urinary oxalates in small quantities may arise from:

a. Tyrosine b. Glycinec. 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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Referencehttps://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, By M. N. Chatterjea, Rana Shinde

1-2 page 323 3-5 page 324

6-24 page 389-390 25-29 page 397

30-31page 460 32-38 page 461

39-46page 462 47-57 page 469

58-69page 529 70-73 page 530

74 page 534

God Bless you abundantly.

Dieu te bnisse abondamment.
https://books.google.com.kh/books?id=I3gC0bX_IKAC&pg=PA323&lpg=PA323&dq#v=onepage&q&f=falsehttps://books.google.com.kh/books?id=I3gC0bX_IKAC&pg=PA323&lpg=PA323&dq#v=onepage&q&f=falsehttps://books.google.com.kh/books?id=I3gC0bX_IKAC&pg=PA323&lpg=PA323&dq#v=onepage&q&f=falsehttps://books.google.com.kh/books?id=I3gC0bX_IKAC&pg=PA323&lpg=PA323&dq#v=onepage&q&f=falsehttps://books.google.com.kh/books?id=I3gC0bX_IKAC&pg=PA323&lpg=PA323&dq#v=onepage&q&f=false

bio-chemistry mcq - no answer

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