Question

Reversible uncompetitive enzyme inhibition occurs when the inhibitor binds to:

• A. \( \text{Enzyme-substrate complex (ES) only} \)
• B. \( \text{Free enzyme at substrate binding site} \)
• C. \( \text{Enzyme at a site different from substrate binding site} \)
• D. \( \text{Enzyme-substrate complex but at a site different from substrate binding site} \)

Hint:

Uncompetitive inhibitors are more effective when substrate concentration is high, reducing enzyme activity.

Answer 1

The Correct Option is A

Uncompetitive inhibitors bind only to the enzyme-substrate (ES) complex, preventing catalysis without affecting substrate binding. This interaction lowers both V\(_{\max}\) and K\(_m\), meaning inhibition becomes more effective at higher substrate concentrations. Unlike competitive inhibition, uncompetitive inhibition requires ES complex formation.