Biology Enzymes MDCAT 2014
PMDC Verified Question 79 of 79
The competitive inhibitors have structural similarity with:
A
Binding site
B
Active site
C
Coenzyme
D
Substrate
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Substrate
Concept:

Enzyme inhibition occurs when a foreign molecule prevents the normal substrate from binding. The mechanism depends on the inhibitor's physical shape.

Solution:

  • A competitive inhibitor is a chemical imposter.
  • It possesses a remarkably close structural similarity to the normal substrate.
  • Because of this mimicry, it fits perfectly into the active site, physically blocking the true substrate from entering and stopping the reaction.


Why other options are incorrect:

The inhibitor mimics the substrate, not the active site itself (it fits into the active site). It does not resemble a coenzyme or the broader binding site.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Enzymes MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App