Biology Digestion/Nutrition MDCAT 2017
PMDC Verified Question 36 of 48
Enzyme pepsin acts on which of the following substrate to produce the respective product?
A
Substrate: Proteins → Product: Polypeptides
B
Substrate: Polypeptide → Product: Dipeptides
C
Substrate: Fats → Product: Fatty acids / glycerol
D
Substrate: Proteins → Product: Amino acids
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Substrate: Proteins → Product: Polypeptides
Concept:

Pepsin is an endopeptidase that operates in the highly acidic environment of the stomach to begin the chemical breakdown of dietary proteins.

Formula:

N/A

Solution:

  • Pepsin acts on large, intact Proteins.
  • It cleaves internal peptide bonds, reducing these massive protein molecules into smaller fragments known as Polypeptides and peptones.
  • It does not complete the digestion down to individual amino acids.


Why other options are incorrect:

Complete breakdown to dipeptides and free amino acids requires pancreatic enzymes (like trypsin/chymotrypsin) and intestinal brush border peptidases. Fats are digested by lipases, not pepsin.

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 Digestion/Nutrition 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