MCQs on Enzymes

1. The nature of an enzyme is
(a) Lipid
(b) Vitamin
(c) Carbohydrate
(d) Protein
Answer: (d)
2. In alcoholism, this enzyme is elevated
(a) acid phosphatase
(b) hepatitis
(c) serum glutamate pyruvate transaminase
(d) glutamyl transpeptidase
Answer: (d)
3. With regards to enzyme action, this statement is incorrect
(a) Malonate is a competitive inhibitor of succinic dehydrogenase
(b) the substrate binds with the enzyme at its active site
(c) the non-competitve inhibitor binds the enzyme at a site distinct from that binding the substrate
(d) addition of a lot of succinates does not reverse the inhibition of succinic dehydrogenase by malonate
Answer: (d)
4. What is the count of genes that determine the synthesis of one enzyme?
(a) One
(b) Four
(c) Eight
(d) Sixteen
Answer: (a)
5. This enzyme was first isolated and purified in the form of crystals
(a) Urease
(b) pepsin
(c) Amylase
(d) Ribonuclease
Answer: (a)
6. Macromolecule chitin is
(a) a simple polysaccharide
(b) sulphur containing polysaccharide
(c) phosphorous containing polysaccharide
(d) nitrogen containing polysaccharide
Answer: (d)
7. Enzyme-driven metabolic pathways can be made more efficient by
(a) grouping enzymes into multienzyme free-floating complexes
(b) concentrating enzymes with specific cellular compartments
(c) fixing enzymes into membranes so they are adjacent to each other
(d) all of these
Answer: (d)
8. Tryptophan synthetase of E.coli, a typical bifunctional oligomeric enzyme consists of
(a) a protein A and one subunit A
(b) a protein designated A
(c) two proteins designated A and B
(d) a protein designated B
Answer: (c)
9. This statement about enzymes is true
(a) enzymes accelerate reactions by lowering the activation energy
(b) enzymes are proteins whose three-dimensional form is key to their function
(c) enzymes do not alter the overall change in free energy for a reaction
(d) all of these
Answer: (d)
10. The enzyme COX-1 is vital for human health in this way:
(a) it is a chemical derivative of aspirin
(b) catalyzes the hormone-production which maintains the stomach lining
(c) critical for the biosynthesis of DNA
(d) helps in the transportation of carbon dioxide in the blood
Answer: (b)