Biology Enzymes MDCAT 2018
PMDC Verified Question 70 of 79
If molecule can bind to another site of the enzyme rather than the true active site, it is referred as
A
Competitive inhibitors
B
Non-allosteric inhibition
C
Irreversible inhibition
D
Non-competitive inhibitors
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Non-competitive inhibitors
Concept:

Inhibition can occur without directly blocking the active site if the enzyme possesses secondary regulatory binding pockets.

Solution:

  • When an inhibitor binds to a distinct, alternate location on the enzyme (an allosteric site), it alters the global 3D structure of the protein.
  • This remote structural distortion ruins the shape of the active site so the substrate can no longer fit.
  • Because it does not compete for the active site itself, it is accurately termed a non-competitive inhibitor.


Why other options are incorrect:

Competitive inhibitors strictly bind to the true active site. Irreversible inhibitors can bind anywhere but the defining feature here is the location (allosteric), not the permanence of the bond.

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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