Question

Which of the following statements about reversible enzyme inhibitors are CORRECT?
P. Uncompetitive inhibitors bind only to the enzyme-substrate complex.
Q. Non-competitive inhibitors bind only at a different site from the substrate.
R. Competitive inhibitors bind to the same site as the substrate.

• A. P and Q only
• B. P and R only
• C. Q and R only
• D. P, Q and R

Hint:

Reversible enzyme inhibitors can be classified based on how they interact with the enzyme and substrate, such as competitive, non-competitive, and uncompetitive inhibitors.

Answer 1

The Correct Option is D

Let’s analyze each statement: - Statement P: Uncompetitive inhibitors bind only to the enzyme-substrate complex. This is true. Uncompetitive inhibitors only bind to the enzyme-substrate complex after the substrate has bound to the enzyme.
- Statement Q: Non-competitive inhibitors bind only at a different site from the substrate. This is true. Non-competitive inhibitors bind to a site distinct from the active site, which can be on the enzyme or enzyme-substrate complex.
- Statement R: Competitive inhibitors bind to the same site as the substrate. This is true. Competitive inhibitors compete with the substrate for binding to the active site of the enzyme.
Thus, all the statements are correct, and the correct answer is (D) P, Q and R.