BIOCHEMISTRY MCQs WITH ANSWER
BIOCHEMISTRY MCQs WITH ANSWER
52. Globular proteins have completely
folded, coiled polypeptide chain and the axial ratio (ratio of length to
breadth) is
(A) Less than 10 and generally not greater than 3–4
(B) Generally 10
(C) Greater than 10 and generally 20
(D) Greater than 10
53. Fibrous proteins have axial ratio
(A) Less than 10
(B) Less than 10 and generally not greater than 3–4
(C) Generally 10
(D) Greater than 10
54. Each turn of α-helix contains the amino acid residues (number):
(A) 3.6
(B) 3.0
(C) 4.2
(D) 4.5
55. Distance traveled per turn of α−helix in nm is
(A) 0.53
(B) 0.54
(C) 0.44
(D) 0.48
56. Along the α-helix each amino acid residue advances in nm by
(A) 0.15
(B) 0.10
(C) 0.12
(D) 0.20
57. The number of helices present in a collagen molecule is
(A) 1
(B) 2
(C) 3
(D) 4
58. In proteins the α-helix and β-pleated sheet are examples of
(A) Primary structure
(B) Secondary structure
(C) Tertiary structure
(D) Quaternary structure
59. The a-helix of proteins is
(A) A pleated structure
(B) Made periodic by disulphide bridges
(C) A non-periodic structure
(D) Stabilised by hydrogen bonds between NH and CO groups of the main chain
60. At the lowest energy level α-helix of polypeptide chain is stabilised
(A) By hydrogen bonds formed between the H of peptide N and the carbonyl O of the residue
(B) Disulphide bonds
(C) Non polar bonds
(D) Ester bonds
61. Both α-helix and β-pleated sheet conformation of proteins were proposed by
(A) Watson and Crick
(B) Pauling and Corey
(C) Waugh and King
(D) Y.S.Rao
62. The primary structure of fibroin, the principal protein of silk worm fibres consists almost entirely of
(A) Glycine
(B) Aspartate
(C) Keratin
(D) Tryptophan
63. Tertiary structure of a protein describes
(A) The order of amino acids
(B) Location of disulphide bonds
(C) Loop regions of proteins
(D) The ways of protein folding
64. In a protein molecule the disulphide bond is not broken by
(A) Reduction
(B) Oxidation
(C) Denaturation
(D) X-ray diffraction
65. The technique for purification of proteins that can be made specific for a given protein is
(A) Gel filtration chromotography
(B) Ion exchange chromatography
(C) Electrophoresis
(D) Affinity chromatography
66. Denaturation of proteins results in
(A) Disruption of primary structure
(B) Breakdown of peptide bonds
(C) Destruction of hydrogen bonds
(D) Irreversible changes in the molecule
(A) Less than 10 and generally not greater than 3–4
(B) Generally 10
(C) Greater than 10 and generally 20
(D) Greater than 10
53. Fibrous proteins have axial ratio
(A) Less than 10
(B) Less than 10 and generally not greater than 3–4
(C) Generally 10
(D) Greater than 10
54. Each turn of α-helix contains the amino acid residues (number):
(A) 3.6
(B) 3.0
(C) 4.2
(D) 4.5
55. Distance traveled per turn of α−helix in nm is
(A) 0.53
(B) 0.54
(C) 0.44
(D) 0.48
56. Along the α-helix each amino acid residue advances in nm by
(A) 0.15
(B) 0.10
(C) 0.12
(D) 0.20
57. The number of helices present in a collagen molecule is
(A) 1
(B) 2
(C) 3
(D) 4
58. In proteins the α-helix and β-pleated sheet are examples of
(A) Primary structure
(B) Secondary structure
(C) Tertiary structure
(D) Quaternary structure
59. The a-helix of proteins is
(A) A pleated structure
(B) Made periodic by disulphide bridges
(C) A non-periodic structure
(D) Stabilised by hydrogen bonds between NH and CO groups of the main chain
60. At the lowest energy level α-helix of polypeptide chain is stabilised
(A) By hydrogen bonds formed between the H of peptide N and the carbonyl O of the residue
(B) Disulphide bonds
(C) Non polar bonds
(D) Ester bonds
61. Both α-helix and β-pleated sheet conformation of proteins were proposed by
(A) Watson and Crick
(B) Pauling and Corey
(C) Waugh and King
(D) Y.S.Rao
62. The primary structure of fibroin, the principal protein of silk worm fibres consists almost entirely of
(A) Glycine
(B) Aspartate
(C) Keratin
(D) Tryptophan
63. Tertiary structure of a protein describes
(A) The order of amino acids
(B) Location of disulphide bonds
(C) Loop regions of proteins
(D) The ways of protein folding
64. In a protein molecule the disulphide bond is not broken by
(A) Reduction
(B) Oxidation
(C) Denaturation
(D) X-ray diffraction
65. The technique for purification of proteins that can be made specific for a given protein is
(A) Gel filtration chromotography
(B) Ion exchange chromatography
(C) Electrophoresis
(D) Affinity chromatography
66. Denaturation of proteins results in
(A) Disruption of primary structure
(B) Breakdown of peptide bonds
(C) Destruction of hydrogen bonds
(D) Irreversible changes in the molecule
67. Ceruloplasmin is
(A) α1-globulin
(B) α2-globulin
(C) β-globulin
(D) None of these
68. The lipoprotein with the fastest electrophoretic mobility and the lowest triglyceride content is
(A) Chylomicron
(B) VLDL
(C) IDL
(D) HDL
69. The lipoprotein associated with activation of LCAT is
(A) HDL
(B) LDL
(C) VLDL
(D) IDL
70. The apolipoprotein which acts as activator of LCAT is
(A) A-I
(B) A-IV
(C) C-II
(D) D
71. The apolipoprotein which acts as actiator of extrahepatic lipoprotein is
(A) Apo-A
(B) Apo-B
(C) Apo-C
(D) Apo-D
72. The apolipoprotein which forms the integral component of chylomicron is
(A) B-100
(B) B-48
(C) C
(D) D
73. The apolipoprotein which from the integral component of VLDL is
(A) B-100
(B) B-48
(C) A
(D) D
74. The apolipoprotein which acts as ligand for LDL receptor is
(A) B-48
(B) B-100
(C) A
(D) C
75. Serum LDL has been found to be increased in
(A) Obstructive jaundice
(B) Hepatic jaundice
(C) Hemolytic jaundice
(D) Malabsorption syndrome
76. A lipoprotein associated with high incidence of coronary atherosclerosis is
(A) LDL
(B) VLDL
(C) IDL
(D) HDL
77. A lipoprotein inversely related to the incidence of coronary artherosclerosis is
(A) VLDL
(B) IDL
(C) LDL
(D) HDL
78. The primary biochemical lesion in homozygote with familial hypercholesterolemia (type IIa) is (A) Loss of feed back inhibition of HMG reductase
(B) Loss of apolipoprotein B
(C) Increased production of LDL from VLDL
(D) Functional deficiency of plasma membrane receptors for LDL
79. In abetalipoproteinemia, the biochemical defect is in
(A) Apo-B synthesis
(B) Lipprotein lipase activity
(C) Cholesterol ester hydrolase
(D) LCAT activity
80. Familial hypertriaacylglycerolemia is associated with
(A) Over production of VLDL
(B) Increased LDL concentration
(C) Increased HDL concentration
(D) Slow clearance of chylomicrons
81. For synthesis of prostaglandins, the essential fatty acids give rise to a fatty acid containing
(A) 12 carbon atoms
(B) 16 carbon atoms
(C) 20 carbon atoms
(D) 24 carbon atoms
82. All active prostaglandins have at least one double bond between positions
(A) 7 and 8
(B) 10 and 11
(C) 13 and 14
(D) 16 and 17
83. Normal range of plasma total phospholipids is
(A) 0.2–0.6 mmol/L
(B) 0.9–2.0 mmol/L
(C) 1.8–5.8 mmol/L
(D) 2.8–5.3 mmol/L
84. HDL2 have the density in the range of
(A) 1.006–1.019
(B) 1.019–1.032
(C) 1.032–1.063
(D) 1.063–1.125
(A) α1-globulin
(B) α2-globulin
(C) β-globulin
(D) None of these
68. The lipoprotein with the fastest electrophoretic mobility and the lowest triglyceride content is
(A) Chylomicron
(B) VLDL
(C) IDL
(D) HDL
69. The lipoprotein associated with activation of LCAT is
(A) HDL
(B) LDL
(C) VLDL
(D) IDL
70. The apolipoprotein which acts as activator of LCAT is
(A) A-I
(B) A-IV
(C) C-II
(D) D
71. The apolipoprotein which acts as actiator of extrahepatic lipoprotein is
(A) Apo-A
(B) Apo-B
(C) Apo-C
(D) Apo-D
72. The apolipoprotein which forms the integral component of chylomicron is
(A) B-100
(B) B-48
(C) C
(D) D
73. The apolipoprotein which from the integral component of VLDL is
(A) B-100
(B) B-48
(C) A
(D) D
74. The apolipoprotein which acts as ligand for LDL receptor is
(A) B-48
(B) B-100
(C) A
(D) C
75. Serum LDL has been found to be increased in
(A) Obstructive jaundice
(B) Hepatic jaundice
(C) Hemolytic jaundice
(D) Malabsorption syndrome
76. A lipoprotein associated with high incidence of coronary atherosclerosis is
(A) LDL
(B) VLDL
(C) IDL
(D) HDL
77. A lipoprotein inversely related to the incidence of coronary artherosclerosis is
(A) VLDL
(B) IDL
(C) LDL
(D) HDL
78. The primary biochemical lesion in homozygote with familial hypercholesterolemia (type IIa) is (A) Loss of feed back inhibition of HMG reductase
(B) Loss of apolipoprotein B
(C) Increased production of LDL from VLDL
(D) Functional deficiency of plasma membrane receptors for LDL
79. In abetalipoproteinemia, the biochemical defect is in
(A) Apo-B synthesis
(B) Lipprotein lipase activity
(C) Cholesterol ester hydrolase
(D) LCAT activity
80. Familial hypertriaacylglycerolemia is associated with
(A) Over production of VLDL
(B) Increased LDL concentration
(C) Increased HDL concentration
(D) Slow clearance of chylomicrons
81. For synthesis of prostaglandins, the essential fatty acids give rise to a fatty acid containing
(A) 12 carbon atoms
(B) 16 carbon atoms
(C) 20 carbon atoms
(D) 24 carbon atoms
82. All active prostaglandins have at least one double bond between positions
(A) 7 and 8
(B) 10 and 11
(C) 13 and 14
(D) 16 and 17
83. Normal range of plasma total phospholipids is
(A) 0.2–0.6 mmol/L
(B) 0.9–2.0 mmol/L
(C) 1.8–5.8 mmol/L
(D) 2.8–5.3 mmol/L
84. HDL2 have the density in the range of
(A) 1.006–1.019
(B) 1.019–1.032
(C) 1.032–1.063
(D) 1.063–1.125
85. β-lipoproteins have the density in the
range of
(A) 0.95–1.006
(B) 1.006–1.019
(C) 1.019–1.063
(D) 1.063–1.125
86. IDL have the density in the range of
(A) 0.95–1.006
(B) 1.006–1.019
(C) 1.019–1.032
(D) 1.032–1.163
87. Aspirin inhibits the activity of the enzyme:
(A) Lipoxygenase
(B) Cyclooxygenase
(C) Phospholipae A1
(D) Phospholipase A2
88. A ’suicide enzyme’ is
(A) Cycloxygenase
(B) Lipooxygenase
(C) Phospholipase A1
(D) Phospholipase A2
89. In ad ipose t issue prostag land ins decrease
(A) Lipogenesis
(B) Lipolysis
(C) Gluconeogenesis
(D) Glycogenolysis
90 The optimal pH for the enzyme pepsin is
(A) 1.0–2.0
(B) 4.0–5.0
(C) 5.2–6.0
(D) 5.8–6.2
91. Pepsinogen is converted to active pepsin by
(A) HCl
(B) Bile salts
(C) Ca++
(D) Enterokinase
92. The optimal pH for the enzyme rennin is
(A) 2.0
(B) 4.0
(C) 8.0
(D) 6.0
93. The optimal pH for the enzyme trypsin is
(A) 1.0–2.0
(B) 2.0–4.0
(C) 5.2–6.2
(D) 5.8–6.2
94. The optimal pH for the enzyme chymotrypsin is
(A) 2.0
(B) 4.0
(C) 6.0
(D) 8.0
95 Trypsinogen is converted to active trypsin by
(A) Enterokinase
(B) Bile salts
(C) HCl
(D) Mg+
(A) 0.95–1.006
(B) 1.006–1.019
(C) 1.019–1.063
(D) 1.063–1.125
86. IDL have the density in the range of
(A) 0.95–1.006
(B) 1.006–1.019
(C) 1.019–1.032
(D) 1.032–1.163
87. Aspirin inhibits the activity of the enzyme:
(A) Lipoxygenase
(B) Cyclooxygenase
(C) Phospholipae A1
(D) Phospholipase A2
88. A ’suicide enzyme’ is
(A) Cycloxygenase
(B) Lipooxygenase
(C) Phospholipase A1
(D) Phospholipase A2
89. In ad ipose t issue prostag land ins decrease
(A) Lipogenesis
(B) Lipolysis
(C) Gluconeogenesis
(D) Glycogenolysis
90 The optimal pH for the enzyme pepsin is
(A) 1.0–2.0
(B) 4.0–5.0
(C) 5.2–6.0
(D) 5.8–6.2
91. Pepsinogen is converted to active pepsin by
(A) HCl
(B) Bile salts
(C) Ca++
(D) Enterokinase
92. The optimal pH for the enzyme rennin is
(A) 2.0
(B) 4.0
(C) 8.0
(D) 6.0
93. The optimal pH for the enzyme trypsin is
(A) 1.0–2.0
(B) 2.0–4.0
(C) 5.2–6.2
(D) 5.8–6.2
94. The optimal pH for the enzyme chymotrypsin is
(A) 2.0
(B) 4.0
(C) 6.0
(D) 8.0
95 Trypsinogen is converted to active trypsin by
(A) Enterokinase
(B) Bile salts
(C) HCl
(D) Mg+
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