Biology Enzymes NUMS 2023
PMDC Verified Question 38 of 79
Non- competitive inhibitors react with enzymes at:
A
Allosteric site
B
Active site
C
Passive site
D
Regulatory site
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Allosteric site
Concept:

Inhibitors that do not mimic the substrate must find an alternative location on the enzyme to exert their effect.

Solution:

  • Non-competitive inhibitors bind to a secondary, distinct pocket on the enzyme's surface.
  • This secondary site is universally referred to in biochemistry as an Allosteric site (from Greek allo meaning 'other' and steric meaning 'shape/space').
  • Binding here triggers a global conformational shift that warps the active site, destroying its ability to bind the substrate.


Why other options are incorrect:

Competitive inhibitors bind to the active site. While an allosteric site acts as a 'regulatory site', the term 'Allosteric site' is the specific, universally accepted terminology for the binding location of non-competitive inhibitors in standard curricula.

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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