Question

Which of the following statements regarding enzyme inhibition is correct

• A. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate
• B. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein
• C. Competitive inhibition is seen when the substrate and the inhibitor compete
• D. Non-competitive inhibitors often bind to the enzyme irreversibly

Answer 1

Answer: (C)

Competitive inhibition is seen when the substrate and the inhibitor compete

Answer 2

The correct statement regarding enzyme inhibition is Competitive inhibition is seen when the substrate and the inhibitor compete.
Explanation:
(A) This statement is not correct. Non-competitive inhibition cannot be overcome by adding more substrate because the inhibitor binds to a different site on the enzyme, not the active site where the substrate binds.
(B) This statement is not entirely accurate. In competitive inhibition, the inhibitor molecule competes with the substrate for binding to the active site of the enzyme, not to an "inhibitor protein."
(D) This statement is also not correct. Non-competitive inhibitors bind to the enzyme reversibly, meaning they can eventually dissociate from the enzyme, although they don't compete with the substrate for the active site.

So, the correct statement is (C): Competitive inhibition is seen when the substrate and the inhibitor compete.