Biology Enzymes UHS 2022
PMDC Verified Question 55 of 79
Competitive inhibitors compete with:
A
Enzyme
B
Substrate
C
Coenzyme
D
Product
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Substrate
Concept:

The active site of an enzyme is a highly specific physical space designed for one type of molecule. If two similar molecules are present, a chemical tug-of-war ensues.

Solution:

  • A competitive inhibitor is structurally analogous (has a very similar shape) to the normal substrate.
  • Because of this similarity, both molecules attempt to bind to the exact same physical location (the active site).
  • Therefore, the competitive inhibitor is directly competing with the substrate for access to the enzyme.


Why other options are incorrect:

It does not compete with the enzyme (it binds TO the enzyme). It does not compete with the product or coenzyme, as they occupy entirely different roles or phases of the reaction.

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