Explore topic-wise MCQs in Chemistry.

This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.

1.

Antagonists do not allow the transfer of message through receptors.

A. True
B. False
Answer» B. False
2.

The drugs that are used when there is a lack of natural chemical messenger is called ______

A. antagonists
B. agonists
C. analgesics
D. narcotics
Answer» C. analgesics
3.

Which of the following is not a reason for the selectivity of receptors towards messengers?

A. Shape of binding site
B. Structure
C. Amino acid composition
D. Location in the membrane
Answer» E.
4.

Which of the following is incorrect regarding receptors?

A. They have constant shape
B. They are proteins
C. The shape of receptors binding site changes to fit the messenger
D. They are present in the cell membrane
Answer» B. They are proteins
5.

If the bond between the enzyme and inhibiting drug is very strong, which of the following takes place?

A. The active site slowly regains its original shape
B. The enzyme develops a new active site
C. The enzyme is blocked temporarily
D. The body synthesizes a new enzyme
Answer» E.
6.

A certain compound occupied a site Y of an enzyme near to the active site. This immediately resulted in the change of shape of the active site. Y is called a/an ______

A. inactive site
B. binding site
C. non-competitive site
D. allosteric site
Answer» E.
7.

A certain compound X occupied a site of an enzyme exactly opposite to that of the active site. This immediately resulted in the change of shape of the active site. X is called a ______

A. competitive inhibitor
B. non-competitive inhibitor
C. competitive messenger
D. receptor
Answer» C. competitive messenger
8.

All drugs block enzyme activity by occupying the active site before the substrate.

A. True
B. False
Answer» C.
9.

Drugs that block the binding site of an enzyme form a substrate are called ______

A. inhibitors
B. poisons
C. messengers
D. receptors
Answer» B. poisons