Biochemistry Questions and Answers – Examples Of Enzymatic actions

This set of Biochemistry Multiple Choice Questions & Answers (MCQs) focuses on “Examples Of Enzymatic actions”.

1. By what factor chymotrypsin enhances the rate of peptide bond hydrolysis?
a) 10⁷
b) 10⁸
c) At least 10⁹
d) 10⁶
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2. The active site of chymotrypsin consists of a catalytic triad of which of the following amino acid residues?
a) Serine, histidine and aspartate
b) Serine, histidine and glutamate
c) Threonine, histidine and aspartate
d) Methionine, histidine and aspartate
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3. Which of the following statements are true about the reactions at the active center of chymotrypsin?
a) The aspartate residue gives an electron to histidine
b) The aspartate residue gives a proton to histidine
c) The aspartate residue keeps the histidine in the correct direction
d) A proton moves from the aspartate to serine to histidine in the catalytic triad of chymotrypsin
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4. The polypeptide chains in chymotrypsin are linked by ___________
a) Hydrogen bonds
b) Ionic bonds
c) Disulfide bond
d) SH-SH bond
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5. Which of the following is false about chymotrypsin?
a) Hydrolytic cleavage of a peptide bond by chymotrypsin has two phases
b) It is activated in the presence of trypsin
c) It is synthesized in the thyroid gland
d) Polypeptide chains in chymotrypsin are linked by S-S bonds
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6. Which of the following is true about the structure of hexokinase?
a) U-shaped
b) T-shaped
c) E-shaped
d) G-shaped
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7. Which of the following is true?
a) Xylose is stereo chemically similar to glucose but one carbon shorter
b) Xylose binds to hexokinase in a position where it can be phosphorylated
c) Addition of xylose increases the rate of ATP hydrolysis
d) The binding of xylose is sufficient to induce a change in hexokinase to its active conformation
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8. Which of the following catalyzes the reversible degradation of 2-phosphoglycerate to phosphoenolpyruvate?
a) Chymotrypsin
b) Hexokinase
c) Enolase
d) Trypsin
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9. Which of the following catalyzes the reversible reaction of β-D-Glucose to glucose 6-phosphate?
a) Chymotrypsin
b) Hexokinase
c) Enolase
d) Trypsin
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10. Which of the following is false about lysozyme?
a) It is an antibacterial agent found in tears and egg white
b) The substrate of lysozyme is peptidoglycan
c) Lysozyme cleaves (β1 → 4) glycosidic C-O bonds between two types of sugar residue in the molecule NAM and NAG
d) It is a bisubstrate enzyme
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Sanfoundry Global Education & Learning Series – Biochemistry.

To practice all areas of Biochemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.