Biology Bioenergetics ETEA 2023 Retake
PMDC Verified Question 31 of 67
What is the number of carbon atoms in pyruvic acid?
A
2
B
3
C
4
D
5
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: 3
Concept:

Glycolysis physically cleaves the carbon skeleton of glucose into two smaller, equal-sized molecules.

Solution:

  • Glucose starts as a 6-carbon molecule (\( C_6H_{12}O_6 \)).
  • It is split directly in half during glycolysis.
  • Therefore, each resulting molecule of pyruvic acid contains exactly 3 carbon atoms.


Why other options are incorrect:

  • 2-carbon compounds form after pyruvate is decarboxylated into Acetyl CoA.
  • 4-carbon and 5-carbon compounds are intermediates in the Krebs cycle.

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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