Question

In the feedback regulation of an enzyme, the end product binds to the

• A. active site of the enzyme.
• B. allosteric site of the enzyme.
• C. enzyme-substrate complex.
• D. substrate.

Hint:

Feedback inhibition regulates enzyme activity by binding the end product to the allosteric site, preventing overproduction.

Answer 1

The Correct Option is B

Step 1: Understanding feedback regulation in enzymes.
In enzyme regulation, the end product of a metabolic pathway often inhibits the enzyme activity through feedback inhibition. This typically occurs when the product binds to an allosteric site, changing the enzyme's conformation.

Step 2: Analyzing the options.
(A) active site of the enzyme: Incorrect — The active site is where the substrate binds for catalysis, not where feedback regulation occurs.
(B) allosteric site of the enzyme: Correct — Feedback regulation involves the end product binding to the allosteric site of the enzyme, leading to a conformational change that inhibits the enzyme's activity.
(C) enzyme-substrate complex: Incorrect — The enzyme-substrate complex is formed during catalysis, not feedback inhibition.
(D) substrate: Incorrect — The substrate binds to the active site, not the product.

Step 3: Conclusion.
The correct answer is (B) allosteric site of the enzyme, where the end product binds for feedback inhibition.