Biochemistry MCQs with answer
Biochemistry MCQs with answer
1. 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
2. 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
3. The primary structure of fibroin, the principal protein of silk worm fibres consists almost entirely of
(A) Glycine
(B) Aspartate
(C) Keratin
(D) Tryptophan
4. 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
5. In a protein molecule the disulphide bond is not broken by
(A) Reduction
(B) Oxidation
(C) Denaturation
(D) X-ray diffraction
6. 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
7. 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) 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
2. 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
3. The primary structure of fibroin, the principal protein of silk worm fibres consists almost entirely of
(A) Glycine
(B) Aspartate
(C) Keratin
(D) Tryptophan
4. 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
5. In a protein molecule the disulphide bond is not broken by
(A) Reduction
(B) Oxidation
(C) Denaturation
(D) X-ray diffraction
6. 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
7. 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
8. Ceruloplasmin is
(A) α1-globulin
(B) α2-globulin
(C) β-globulin
(D) None of these
9. The lipoprotein with the fastest electrophoretic mobility and the lowest triglyceride content is
(A) Chylomicron
(B) VLDL
(C) IDL
(D) HDL
10. The lipoprotein associated with activation of LCAT is
(A) HDL
(B) LDL
(C) VLDL
(D) IDL
11. The apolipoprotein which acts as activator of LCAT is
(A) A-I
(B) A-IV
(C) C-II
(D) D
12. The apolipoprotein which acts as actiator of extrahepatic lipoprotein is
(A) Apo-A
(B) Apo-B
(C) Apo-C
(D) Apo-D
13. The apolipoprotein which forms the integral component of chylomicron is
(A) B-100
(B) B-48
(C) C
(D) D
14. The apolipoprotein which from the integral component of VLDL is
(A) B-100
(B) B-48
(C) A
(D) D
15. The apolipoprotein which acts as ligand for LDL receptor is
(A) B-48
(B) B-100
(C) A
(D) C
16. Serum LDL has been found to be increased in
(A) Obstructive jaundice
(B) Hepatic jaundice
(C) Hemolytic jaundice
(D) Malabsorption syndrome
17. A lipoprotein associated with high incidence of coronary atherosclerosis is
(A) LDL
(B) VLDL
(C) IDL
(D) HDL
18. A lipoprotein inversely related to the incidence of coronary artherosclerosis is
(A) VLDL
(B) IDL
(C) LDL
(D) HDL
19. 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
20. In abetalipoproteinemia, the biochemical defect is in
(A) Apo-B synthesis
(B) Lipprotein lipase activity
(C) Cholesterol ester hydrolase
(D) LCAT activity
21. Familial hypertriaacylglycerolemia is associated with
(A) Over production of VLDL
(B) Increased LDL concentration
(C) Increased HDL concentration
(D) Slow clearance of chylomicrons
22. 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
23. 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
24. 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
25. 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
9. The lipoprotein with the fastest electrophoretic mobility and the lowest triglyceride content is
(A) Chylomicron
(B) VLDL
(C) IDL
(D) HDL
10. The lipoprotein associated with activation of LCAT is
(A) HDL
(B) LDL
(C) VLDL
(D) IDL
11. The apolipoprotein which acts as activator of LCAT is
(A) A-I
(B) A-IV
(C) C-II
(D) D
12. The apolipoprotein which acts as actiator of extrahepatic lipoprotein is
(A) Apo-A
(B) Apo-B
(C) Apo-C
(D) Apo-D
13. The apolipoprotein which forms the integral component of chylomicron is
(A) B-100
(B) B-48
(C) C
(D) D
14. The apolipoprotein which from the integral component of VLDL is
(A) B-100
(B) B-48
(C) A
(D) D
15. The apolipoprotein which acts as ligand for LDL receptor is
(A) B-48
(B) B-100
(C) A
(D) C
16. Serum LDL has been found to be increased in
(A) Obstructive jaundice
(B) Hepatic jaundice
(C) Hemolytic jaundice
(D) Malabsorption syndrome
17. A lipoprotein associated with high incidence of coronary atherosclerosis is
(A) LDL
(B) VLDL
(C) IDL
(D) HDL
18. A lipoprotein inversely related to the incidence of coronary artherosclerosis is
(A) VLDL
(B) IDL
(C) LDL
(D) HDL
19. 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
20. In abetalipoproteinemia, the biochemical defect is in
(A) Apo-B synthesis
(B) Lipprotein lipase activity
(C) Cholesterol ester hydrolase
(D) LCAT activity
21. Familial hypertriaacylglycerolemia is associated with
(A) Over production of VLDL
(B) Increased LDL concentration
(C) Increased HDL concentration
(D) Slow clearance of chylomicrons
22. 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
23. 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
24. 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
25. 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
26. 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
27. 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
28. Aspirin inhibits the activity of the enzyme:
(A) Lipoxygenase
(B) Cyclooxygenase
(C) Phospholipae A1
(D) Phospholipase A2
29. A ’suicide enzyme’ is
(A) Cycloxygenase
(B) Lipooxygenase
(C) Phospholipase A1
(D) Phospholipase A2
30. In ad ipose t issue prostag land ins decrease
(A) Lipogenesis
(B) Lipolysis
(C) Gluconeogenesis
(D) Glycogenolysis
31 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
32. Pepsinogen is converted to active pepsin by
(A) HCl
(B) Bile salts
(C) Ca++
(D) Enterokinase
33. The optimal pH for the enzyme rennin is
(A) 2.0
(B) 4.0
(C) 8.0
(D) 6.0
34. 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
35. The optimal pH for the enzyme chymotrypsin is
(A) 2.0
(B) 4.0
(C) 6.0
(D) 8.0
36 Trypsinogen is converted to active trypsin by
(A) Enterokinase
(B) Bile salts
(C) HCl
(D) Mg++
37 Pepsin acts on denatured proteins to produce
(A) Proteoses and peptones
(B) Polypeptides
(C) Peptides
(D) Dipeptides
38. Renin converts casein to paracasein in presence of
(A) Ca++
(B) Mg++
(C) Na+
(D) K+
39. An expopeptidase is
(A) Trypsin
(B) Chymotrypsin
(C) Elastase
(D) Elastase
40. The enzyme trypsin is specific for peptide bonds of
(A) Basic amino acids
(B) Acidic amino acids
(C) Aromatic amino acids
(D) Next to small amino acid residues
41. Chymotrypsin is specific for peptide bonds containing
(A) Uncharged amino acid residues
(B) Acidic amino acids
(C) Basic amino acid
(D) Small amino acid residues
42. The end product of protein digestion in G.I.T. is
(A) Dipeptide
(B) Tripeptide
(C) Polypeptide
(D) Amino acid
43. Natural L-isomers of amino acids are absorbed from intestine by
(A) Passive diffusion
(B) Simple diffusion
(C) Faciliated diffusion
(D) Active process
44. Abnormalities of blood clotting are
(A) Haemophilia
(B) Christmas disease
(C) Gout
(D) Both (A) and (B)
45. An important reaction for the synthesis of amino acid from carbohydrate intermediates is transamination which requires the cofactor:
(A) Thiamin
(B) Riboflavin
(C) Niacin
(D) Pyridoxal phosphate
(A) 0.95–1.006
(B) 1.006–1.019
(C) 1.019–1.063
(D) 1.063–1.125
27. 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
28. Aspirin inhibits the activity of the enzyme:
(A) Lipoxygenase
(B) Cyclooxygenase
(C) Phospholipae A1
(D) Phospholipase A2
29. A ’suicide enzyme’ is
(A) Cycloxygenase
(B) Lipooxygenase
(C) Phospholipase A1
(D) Phospholipase A2
30. In ad ipose t issue prostag land ins decrease
(A) Lipogenesis
(B) Lipolysis
(C) Gluconeogenesis
(D) Glycogenolysis
31 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
32. Pepsinogen is converted to active pepsin by
(A) HCl
(B) Bile salts
(C) Ca++
(D) Enterokinase
33. The optimal pH for the enzyme rennin is
(A) 2.0
(B) 4.0
(C) 8.0
(D) 6.0
34. 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
35. The optimal pH for the enzyme chymotrypsin is
(A) 2.0
(B) 4.0
(C) 6.0
(D) 8.0
36 Trypsinogen is converted to active trypsin by
(A) Enterokinase
(B) Bile salts
(C) HCl
(D) Mg++
37 Pepsin acts on denatured proteins to produce
(A) Proteoses and peptones
(B) Polypeptides
(C) Peptides
(D) Dipeptides
38. Renin converts casein to paracasein in presence of
(A) Ca++
(B) Mg++
(C) Na+
(D) K+
39. An expopeptidase is
(A) Trypsin
(B) Chymotrypsin
(C) Elastase
(D) Elastase
40. The enzyme trypsin is specific for peptide bonds of
(A) Basic amino acids
(B) Acidic amino acids
(C) Aromatic amino acids
(D) Next to small amino acid residues
41. Chymotrypsin is specific for peptide bonds containing
(A) Uncharged amino acid residues
(B) Acidic amino acids
(C) Basic amino acid
(D) Small amino acid residues
42. The end product of protein digestion in G.I.T. is
(A) Dipeptide
(B) Tripeptide
(C) Polypeptide
(D) Amino acid
43. Natural L-isomers of amino acids are absorbed from intestine by
(A) Passive diffusion
(B) Simple diffusion
(C) Faciliated diffusion
(D) Active process
44. Abnormalities of blood clotting are
(A) Haemophilia
(B) Christmas disease
(C) Gout
(D) Both (A) and (B)
45. An important reaction for the synthesis of amino acid from carbohydrate intermediates is transamination which requires the cofactor:
(A) Thiamin
(B) Riboflavin
(C) Niacin
(D) Pyridoxal phosphate
46. The main sites for oxidative deamination are
(A) Liver and kidney
(B) Skin and pancreas
(C) Intestine and mammary gland
(D) Lung and spleen
No comments