Biology Bioenergetics UHS 2024
PMDC Verified Question 11 of 67
Which option is correct about a chlorophyll molecule?
A
Chemical formula \( C_{55}H_{70}O_{6}N_{4}Mg \)
B
Porphyrin ring with nitrogen in centre
C
Methyl group on second pyrrole ring
D
Aldehyde group on second pyrrole ring
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Chemical formula \( C_{55}H_{70}O_{6}N_{4}Mg \)
Concept:

There are different forms of chlorophyll (primarily a and b), each with a highly specific molecular formula and functional group.

Solution:

  • The chemical formula \( C_{55}H_{70}O_{6}N_{4}Mg \) is the exact molecular formula for Chlorophyll b.
  • Since Chlorophyll b is definitively "a chlorophyll molecule," this statement is completely accurate.


Why other options are incorrect:

  • Option B: The center of the porphyrin ring contains Magnesium (\( Mg \)), not Nitrogen. The nitrogen atoms strictly coordinate the central Magnesium.
  • Option C & D: These are specific differentiators. Chlorophyll a has a methyl group, and Chlorophyll b has an aldehyde group, but a general formula is universally true for its specific type.

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 Bioenergetics 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