Biology Enzymes ETEA 2023 Retake
PMDC Verified Question 25 of 79
What is 'flavin adenine dinucleotide'?
A
Coenzyme
B
Enzyme
C
Catalyst
D
Cofactor
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Coenzyme
Concept:

Flavin Adenine Dinucleotide (FAD) is a crucial electron carrier utilized primarily in the Krebs cycle during cellular respiration.

Solution:

  • FAD is an organic, non-protein helper molecule.
  • It works closely with specific oxidoreductase enzymes to accept electrons (becoming \( \text{FADH}_2 \)) and then transport them to the electron transport chain.
  • Because it is a detachable, organic molecule derived from a vitamin (riboflavin), its exact biochemical classification is a Coenzyme.


Why other options are incorrect:

FAD is not a protein, so it cannot be an enzyme. While it is technically a sub-type of cofactor, 'coenzyme' is the most accurate and specific classification for organic dinucleotides like FAD and NAD.

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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