Biology Enzymes NUMS 2023
PMDC Verified Question 37 of 79
____ reduce the enzyme productivity by blocking the substrate entering into the active site due to similar shapes.
A
Competitive inhibitors
B
Non-competitive inhibitors
C
Co- enzymes
D
Activators
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Competitive inhibitors
Concept:

Enzyme inhibition can occur via a direct physical blockade of the catalytic site.

Solution:

  • Competitive inhibitors possess a 3D molecular geometry that is remarkably similar to the natural substrate.
  • Due to this structural mimicry, they compete for and bind directly to the active site.
  • This acts as a physical plug, strictly blocking the true substrate from entering and consequently reducing overall enzyme productivity.


Why other options are incorrect:

Non-competitive inhibitors bind elsewhere (allosteric sites) and change the enzyme's shape, rather than directly blocking the entrance. Co-enzymes and activators are essential helpers that increase, not reduce, productivity.

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.

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