Biology Bioenergetics ETEA 2023 Retake
PMDC Verified Question 41 of 67
In the non-cyclic electron transport of light reaction, the deficit of _ electrons occur in the chlorophyll, as it absorbs energy.
A
1
B
2
C
3
D
4
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: 2
Concept:

Non-cyclic photophosphorylation (Z-scheme) relies on a continuous flow of electrons from water, through the photosystems, to NADP+.

Solution:

  • When light strikes Photosystem II (P680), an excited pair of electrons is ejected.
  • This creates a deficit of exactly 2 electrons in the chlorophyll a reaction center.
  • To fill this hole, one molecule of water is split (photolysis) to provide exactly 2 replacement electrons.


Why other options are incorrect:

  • The biological mechanism of photolysis specifically yields 2 electrons per water molecule split, perfectly matching the 2-electron deficit in the activated photosystem.

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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