Biology Enzymes KMU 2024
PMDC Verified Question 14 of 79
A competitive inhibitor:
A
Accelerates the chemical reaction
B
Competes with the enzyme
C
Is irreversible
D
Is reversible
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Is reversible
Concept:

Competitive inhibition relies on molecular mimicry. Because the bonds formed are temporary, the system can be manipulated by changing concentrations.

Solution:

  • Competitive inhibitors mimic the substrate and bind to the active site using weak, non-covalent interactions (like hydrogen bonds).
  • Because these bonds are weak, the inhibitor frequently attaches and detaches.
  • If the normal substrate concentration is heavily increased, it will outcompete the inhibitor for the active site, proving that the inhibition is reversible.


Why other options are incorrect:

Inhibitors decelerate, not accelerate, reactions. It competes with the substrate (for access to the enzyme), it does not compete with the enzyme itself. By definition, true competitive inhibitors are reversible (unlike heavy metals).

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