PACOP BLUE (BIOCHEMISTRY)

1. What two enzymes are used to bypass the pyruvate kinase reaction of glycolysis? I. pyruvate carboxylase II. PEP carboxykinase III. Fructose biphosphatase IV. Glucose-6-phosphate A. I & II B. III & IV C. I & III D. II & IV E. II & III

A. I & II

2. Which of the following includes the main goals of Pentose Phosphate Pathway? I. produce ribose-5-phosphate for nucleotide synthesis II. produce NADPH and NADP for oxidoreductive biochemical synthesis III. to interconvert pentoses and hexoses A. I & II B. II & III C. I & III D. I, II & III

D. I, II & III

3. Which of the following statements is/are true regarding the secondary structure of nucleic acids? I. Guanine forms base pairs with cytosine via 2 hydrogen bonds II. The B form of the DNA is the most common in biological systems III. The breaking of H-bonds caused by high temperature is called melting A. I, II & III B. I & II C. II & III D. I & II E. II only

C. II & III

4. The phospholipid, phosphatidylinositol 4,5-biphosphate forms the potent secondary messengers inositol triphosphate & diacylglycerol via what enzyme? A. Phospholipase A B. Phospholipase C C. Phospholipase D D. Phospholipase B

B. Phospholipase C

5. Which of the following is not true regarding the four enzyme complexes of the electron transport chain? A. Complex I is known as the NADH-CoQ Oxidoreductases B. Complex II is known as Succinate-CoQ Oxidoreductases C. Complex III is known as Cytochrome Oxidase D. Complex IV is known as Cytochrome Oxidase

C. Complex III is known as Cytochrome Oxidase

6. Glucose and mannose are epimers at: A. Carbon 4 B. Carbon 2 C. Carbon 3 D. Carbon 5

B. Carbon 2

7. One important endogenous molecule for synthetic biotransformation of xenobiotics is glucoronic acid. It is actually the most dominant conjugative biotransformation pathway due to the readily available source of glucose. It is produce from glucose via: A. Oxidation at carbon 1 B. Oxidation at carbon 2 C. Oxidation at carbon 6 D. Oxidation at carbon 1 & 6

C. Oxidation at carbon 6

8. Which of the following is not true about protein structure determination? A. NMR is the primary means of determining protein structure B. Protein are difficult to crystallize, a disadvantage of x-ray crystallography C. An advantage of the use of the NMR is that proteins analyzed are in their natural state D. Large and very complex proteins can only be analyzed by x-ray crystallography

A. NMR is the primary means of determining protein structure

9. Tertiary structures of proteins are primarily stabilized by I. H-bonds II. Hydrophobic interactions III. Ionic bonds IV. Disulfide bonds A. I & III B. II & IV C. I, III & IV D. I, II & IV E. II, III & IV

E. II, III & IV

10. In an uncompetitive inhibition of enzymatic action: A. Inhibitor binds either to the free enzyme or the enzyme substrate complex B. Lineweaver-Burk plots of the enzyme alone (control) & the enzyme + inhibitor are parallel to each other C. The apparent Km is raised D. The Vmax is unaffected

B. Lineweaver-Burk plots of the enzyme alone (control) & the enzyme + inhibitor are parallel to each other

11. Which biomolecule is not considered a biopolymer? A. Proteins B. Lipids C. Carbohydrates D. Nucleic acids E. Fat

B. Lipids / E. Fat

12. It is regarded as the universal biological energy currency A. Adenosine triphosphate B. Guanosine triphosphate C. Uncouplers D. Calories

A. Adenosine triphosphate

13. This is the final electron receptor of the electron transport chain A. Complex I B. Complex II C. Complex V D. Complex IV

D. Complex IV

14. The most accepted hypothesis regarding oxidative phosphorylation is A. Chemical coupling B. Conformational coupling C. Chemiostatic hypothesis D. Lock and Key Theory E. Diffusion

C. Chemiostatic hypothesis

15. This is a quantitative study of the energy transformations in the living cell A. Bioenergetics B. Thermodynamics C. Proteonomics D. Metabolomics

A. Bioenergetics

16. Which of the following hormones promotes rapid glycogenolysis in both liver and muscle A. ACTH B. Glutemine C. Epinephrine D. Prolactin

C. Epinephrine

17. Which vitamin can be used in the management of hyperlipidemia? A. Thiamine B. Riboflavin C. Niacin D. Panthotenic acid

C. Niacin

18. Bond between 2 amino acids A. Glycosidic bond B. N-glycosyl linkage C. Peptide Bond D. Hydrogen bond

C. Peptide Bond

19. Beta oxidation of fatty acids occurs in the A. Cytosol B. Mitochondria C. Endoplasmic reticulum D. Ribosomes

B. Mitochondria

20. The pentose phosphate pathway occur in the _____ of the liver, muscle and kidney. A. cytosol B. mitochondria C. endoplasmic reticulum D. ribosomes

A. cytosol

21. The isoelectric point is the A. pH where the alpha amino acid exist in its negatively charged form B. pH wherein the amino acid exist in zwitterionic form C. Temperature at which the amino acid denatures D. Pressure at which the amino acid hydrolyzes

B. pH wherein the amino acid exist in zwitterionic form

22. This is the only optically inactive amino acid A. methionine B. Lysine C. Citrulline D. glycine

D. glycine

23. This level of protein structure is applicable only to those have several subunits A. Primary B. Secondary C. Tertiary D. Quaternary

D. Quaternary

24. Arginine is the only metabolite of the urea cycle that does not accumulate because A. It is readily excreted B. It is used up by the body for protein synthesis C. There is no known deficiency in the enzyme that catabolizes it D. It can ve acquired from food

C. There is no known deficiency in the enzyme that catabolizes it

25. This is the genetic condition characterized by deficiency of the enzyme branched chain alpha-keto acid dehydrogenase A. Maple syrup disease B. Hartnup disease C. Kwashiorkor D. Marasmus

A. Maple syrup disease

26. These are compounds related to cerebrosides that contain sphingosine, long chain fatty acids, hexoses (usually galactose or glucose) and neuraminic acid A. cephalins B. gangliosides C. cytolipins D. lecithins

B. gangliosides

27. This enzyme catalyzes the conversion fructose-6-P to fructose-1,6-bis-P A. hexokinase B. pyruvate kinase C. PFK D. glyceraldehyde phosphate dehydrogenase

C. PFK

28. Which of the following is called transamination? A. Conversion of amino acids to hydroxyl groups B. Conversion of amino acids to keto acids C. Loss of ammonia from amino acids D. Formation of ammonium salts from ammonia

B. Conversion of amino acids to keto acids

29. The sugar involved in the DNA A. ribose B. pentose C. deoxyribose D. xylose

C. deoxyribose

30. This is the reason why blood AB is considered as the universal recipient. A. It is the most common among the ABO blood types B. Blood type AB has neither A nor B substances C. Blood type AB has neither anti-A nor anti-B antibodies D. All of the above

C. Blood type AB has neither anti-A nor anti-B antibodies

31. Which one is true regarding the structures of lipids? A. Eicosanopentanoic acid is a saturated fatty acid B. They may exist as esters of cholesterol when they are enclosed in very low density C. Linoleic acid is an omega-3 fatty acid D. Capric acid contains 12 carbons

B. They may exist as esters of cholesterol when they are enclosed in very low density

32. This is the product of basic hydrolysis of fats and oils A. fatty acid B. triacylglycerol C. soap D. detergent

C. soap

33. The group of lipids is considered amphipathic A. sterols B. fatty acids C. trans-fatty acids D. phospholipids

D. phospholipids

34. Which properly describes a liposome? A. It is a hollow sphere-like structure composed of a lipid bilayer enclosing an aqueous cavity B. It is a lipid structure wherein the hydrophobic chains of the fatty acids are sequestered at the core of the sphere with virtually no water in the hydrophobic interior C. It is a lipoprotein integrated in the phospholipid bilayer of the cell membranes D. It is a hollow sphere-like structure composed of a lipid monolayer enclosing a hydrophobic cavity

A. It is a hollow sphere-like structure composed of a lipid bilayer enclosing an aqueous cavity

35. It is the building block of essential fatty acids A. Malonyl CoA B. phosphoribosyl pyrophosphate C. Acetyl CoA D. HMG CoA

C. Acetyl CoA

36. The digestion of carbohydrates begins in the A. mouth B. stomach C. small intestine D. duodenum

A. mouth

37. Cellular elements of the blood devoid of nucleus A. RBC B. WBC C. thrombocytes D. all of the above

D. all of the above

38. Conjugated proteins which are a combination of amino acids and carbohydrates A. nucleoproteins B. glycoproteins C. phosphoproteins D. chromoproteins

B. glycoproteins

39. Glucose is normally absent in the urine because kidneys normally completely reabsorb all glucose. Which of the following is true? A. Glucosuria confirms diabetes mellitus B. Glucosuria necessarily means hyperglycemia C. Glucosuria is solely attributed to insulin problem D. Glucosuria may occur in other disease states

D. Glucosuria may occur in other disease states

40. Wernicke-Korsakoff syndrome which can cause acute confusion, ataxia and opthalmoplegia, can be treated with which of the following? A. riboflavin B. ascorbic acid C. thiamine D. pantothenic acid

C. thiamine

41. This is the major excretory product of purine nucleotides A. inosine monophosphate B. uric acid C. methylmalonyl CoA D. tetrahydrofolate

B. uric acid

42. This is the phenomena of renaturation of nucleic acid after it has been subjected to high then to room temperature A. Hydrolysis B. Polymerase chain reaction C. annealing D. hybridization

C. annealing

43. This is the base sequence for the start codon A. UAG B. UGA C. AUG D. UAA

C. AUG

44. This feature of bacterial cells confers selectivity of antibacterial agents targeting protein synthesis to the bacteria and not to the host cell. A. mRNA B. 40s ribosomal subunit C. lack of cell wall D. 30s ribosomal subunit

D. 30s ribosomal subunit

45. This is also known as the RNA-directed DNA polymerase A. RNA polymerase II B. Reverse transcriptase C. DNA polymerase alpha D. DNA polymerase II

B. Reverse transcriptase

46. What essential amino acid is used in the synthesis of niacin? A. Tyrosine B. Methionine C. tryptophan D. Phenylalanine

C. tryptophan

47. The cellular particles are often referred by their sedimentation coefficient value, for example 70s ribosomes that is expressed in terms of 10-13 seconds. The abbreviation "s" stands for A. subunit B. Seconds C. Svedberg D. None of the above

C. Svedberg

48. The best known building blocks of RNA and DNA are A. purines B. pyrimidines C. fatty acids D. a and b

D. a and b

49. The following are pathological constituents of urine, except: A. glucose B. albumin C. creatinine D. blood

C. creatinine

50. Glucose and galactose differ only in the configuration of their hydroxyl group at carbon 4. Glucose and galactose are A. diastereomers B. enantiomers C. epimers D. anomers

C. epimers

51. The chemical representation shows the most stable conformation of hexoaldopyranoses A. Fischer projection B. Boat conformation C. Haworth Formula D. Chair conformation

D. Chair conformation

52. It is the most abundant hexose inside the body A. L-glucose B. D-glucose C. L-ribose D. D ribose

B. D-glucose

53. Upon hydrolysis sucrose yields A. glucose and galactose B. xylose and glucose C. fructose and glucose D. 2 glucose units

C. fructose and glucose

54. This is the process of biosynthesis of glucose from non-carbohydrate precursors A. glycolysis B. glycogenesis C. gluconeogenesis D. glycogenolysis

C. gluconeogenesis

55. Which is most likely the effect of insulin in glucose metabolism A. It promotes lipolysis in adipose tissue B. It promotes exocytosis of glucose transporters in the skeletal muscles C. Activates protein kinase A which eventually leads to inactivation of pyruvate kinase D. It promotes the hormonal role of glucagon in glucose metabolism

B. It promotes exocytosis of glucose transporters in the skeletal muscles

56. The activation of plasminogen requires A. NaOH B. bicarbonate C. acetic acid D. HCl

D. HCl

57. Glucose, fructose and galactose all have the same chemical formula C6H12O6, through this information, we can conclude that these substances are A. Anomers B. Epimers C. enantiomers D. isomers

D. isomers

58. The end product in the hydrolysis of glycogen is A. galactose B. mannose C. glucose D. arabinose

C. glucose

59. Ketoses can be differentiated from aldose by this test A. Molisch's test B. Benedict's test C. Seliwanoff's test D. Tollen's test

C. Seliwanoff's test

60. Which of the following statements is/are correct? I. The difference between intake and output of nitrogenous compounds is known as hydrogen balance II. In a healthy adult, nitrogen balance is in equilibrium when intake equals output III. Positive nitrogen balance occurs when dietary intake is less than excretion of nitrogenous compounds IV. Negative nitrogen balance results when there is too much protein intake A. 3 only B. 1 & 2 C. 1 & 3 D. 2 & 4 E. 1-4

B. 1 & 2

61. The formation of purple ring at the junction of the acid and sugar layers in the Molisch's test detects the presence of A. carbohydrates B. proteins C. lipids D. nucleic acids

A. carbohydrates

62. The observance of a red colored solution in Seliwanoff's test detects the presence of A. Aldoses B. Ketohexoses C. Pentoses D. Saccharides

B. Ketohexoses

63. This test distinguishes between reducing sugar monosaccharides and reducing disaccharides based on the difference in the rate of reaction. A. Barfoed's test B. Benedict's test C. Osazone test D. Mucic acid test

A. Barfoed's test

64. In xanthoproteic test, proteins with aromatic amino acids undergo _____ to give an intense yellow colored solution in alkaline media. A. condensation B. Acetylation C. nitration D. oxidation

C. nitration

65. Biuret test forms _____ colored complex with cupric ion in basic solutions of compounds with 2 or more peptide bonds. A. green B. red C. violet D. yellow

C. violet

66. When starches are heated they produce A. Sugars B. Glycogen C. dextrin D. disaccharides

C. dextrin

67. The principal end product of protein metabolism A. carbon dioxide B. ammonia C. hippuric acid D. urea

D. urea

68. Myoglobin and hemoglobin possess a cyclic tetrapyrole, heme, as a prosthetic group. Which of the following is found centrally located in the heme? A. Mg B. Al C. Fe D. P

C. Fe

69. The following are the components of DNA nucleosides except A. phosphoric acid B. sugar C. adenine D. cytosine

A. phosphoric acid

70. The enzyme decarboxylase is an example of _____ enzyme. A. hydrolase B. ligase C. racemase D. lyase

D. lyase

71. The spontaneous isomerization of two stereoisomers in aqueous solution that causes specific rotation is known as A. zwitterions rotation B. micelle rotation C. mutarotation D. stereorotation

C. mutarotation

72. Which of the following is a polysaccharide? A. dextrose B. dextran C. lactose D. sucrose

B. dextran

73. The substance that is isolated from the brain and produces fatty acid, galactose and sphingosine upon hydrolysis is known as A. sterols B. phospholipids C. glycolipids D. saponins

C. glycolipids

74. Which of the following is NOT a hydrolyzed product of lecithins? A. fatty acid B. glycerol C. phosphoric acid D. sphingosine

D. sphingosine

75. Albumin is an example of a A. simple protein B. conjugated protein C. derived protein D. hydrolyzed protein

A. simple protein

76. This is the product of the complete reduction of oxygen A. water B. Superoxide anions C. hydrogen peroxide D. hydroxyl radicals

A. water

77. Which is not a B-complex vitamin? A. folic acid B. nicotinic acid C. riboflavin D. ascorbic acid

D. ascorbic acid

78. Rotation of polarized light is caused by the solution of all the following amino acids except A. alanine B. glycine C. leucine D. valine

B. glycine

79. What test can be used to differentiate galactose from lactose? A. Benedict's test B. Iodine test C. Barfoed's test D. Mucic acid test

C. Barfoed's test

80. Alpha-naphthol reaction is also known as A. Molisch's test B. Ninhydrin test C. Phenylhydrazine test D. Fehling's test

A. Molisch's test

81. Which of the following is not about PKU? A. A high concentration of phenylpyruvic acid is found in the urine B. It is a disease usually characterized by mental abnormalities C. It occurs due to excessive secretion of phenylalanine hydroxylase enzyme D. A Guthrie test is normally used to detect it

C. It occurs due to excessive secretion of phenylalanine hydroxylase enzyme

82. Sweet taste of a compound is generally attributed to A. presence of H ions B. presence of OH ions C. presence of cations and anions D. presence of alkaloids

B. presence of OH ions

83. The rate of hydrolysis depends on I. pressure II. pH of the solution III. Temperature A. I only B. I & II only C. II & III only D. I, II & III

D. I, II & III

84. Which of the following is NOT recommended to treat hypoglycemia induced by acarbose? A. dextrose B. table sugar C. glucagon D. glucose

B. table sugar

85. Which of the following is normally NOT found in the bacterial bit present in human cells? A. golgi body B. mitochondria C. lysosome D. endoplasmic reticulum

A. golgi body / B. mitochondria / C. lysosome / D. endoplasmic reticulum

86. This term refers to an intact enzyme with a bound co-factor. A. holoenzyme B. apoenzyme C. zymogen D. prosthetic group

A. holoenzyme

87. The color of the skin, hair and eyes is due to a pigment called A. cytochrome B. melanin C. keratin D. heparin

B. melanin

88. Serotonin is synthesized from this amino acid A. tryptophan B. threonine C. tyrosine D. alanine

A. tryptophan

89. Keratin in hair and horny tissue, elastin in tendons and arteries, and collagen in skin and tendons belong to what type of simple proteins? A. glutelins B. histones C. protamines D. albuminoids

D. albuminoids

90. Nucleosides upon hydrolysis will yield A. adenine + phosphate B. quinine + phosphate C. histones + ribose D. cytosine + ribose

D. cytosine + ribose

91. Which of the following is/are true about lysozyme? I. It is generally known as the power house of the cell. II. It helps in the removal of damaged cell III. It contains a bactericidal agent such as lysozyme that kills bacteria before it damages the cell. A. I only B. I & II only C. II & III only D. I, II & III only

C. II & III only

92. Which of the following is the rate limiting step in synthesis of RBC? A. availability of pre-erythrocytes B. availability of hemoglobin C. oxygen transport capacity D. presence of erythropoietin

D. presence of erythropoietin

93. Which of the following helps in absorption of vitamin B12? A. erythropoietin B. intrinsic factor C. hemoglobin D. apoferritin

B. intrinsic factor

94. Which of the following factors affect the solubility of solutes? I. temperature II. pH III. Common ion effects A. I only B. I & II only C. II & III only D. I, II & III

D. I, II & III

95. Which of the following factors affect the protein binding drugs? I. pregnancy II. Hypoalbuminemia III. Uremia A. I only B. I & II only C. II & III only D. I, II & III

D. I, II & III

96. Some serum enzymes are used in clinical diagnosis. Which of the following enzyme/s may be used to diagnose myocardial infarction? I. gamma-glutamyl transpeptidase II. AST or SGOT III. Creatine phosphokinase IV. Lactate dehydrogenase A. III only B. II & IV only C. I, II & III D. II, III & IV

D. II, III & IV

97. Which of the following test is specific for amino acids and free amino group? A. Biuret test B. Hopkin's cole test C. Ninhydrin test D. Xanthoproteic test

C. Ninhydrin test

98. The following sugars are aldohexoses except A. fructose B. galactose C. glucose D. mannose

A. fructose

99. Arrange the following secondary derived proteins from highest to lowest molecular weight. A. peptides > peptones > proteoses B. proteoses > peptides > peptones C. proteoses > peptones > peptides D. peptones > proteoses > peptides

C. proteoses > peptones > peptides

100. Is the sum total of all activities directed towards the maintenance of life A. catabolism B. anabolism C. metabolism D. photosynthesis E. fermentation

C. metabolism