During non cyclic electron transport, after excitation by light, Chl+ is unstable, seeks to replace lost electrons. What is the immediate consequence?

Prepare for the Foundations of Biology Exam 1. Dive into key biological concepts with multiple choice questions, hints, and explanations. Ace the exam with our efficient study methods!

Multiple Choice

During non cyclic electron transport, after excitation by light, Chl+ is unstable, seeks to replace lost electrons. What is the immediate consequence?

When PSII absorbs light, the P680 chlorophyll donor becomes P680+, an unstable state that needs an electron. The quickest way to restore it is to pull electrons from water. The oxygen-evolving complex splits water, yielding electrons to refill PSII, protons into the lumen, and molecular oxygen released as O2. This immediate step not only keeps the electron transport chain moving but also creates the proton gradient that ultimately drives ATP synthesis and, downstream, NADPH formation. So the immediate consequence is water splitting by PSII producing O2, H+, and electrons.

When PSII absorbs light, the P680 chlorophyll donor becomes P680+, an unstable state that needs an electron. The quickest way to restore it is to pull electrons from water. The oxygen-evolving complex splits water, yielding electrons to refill PSII, protons into the lumen, and molecular oxygen released as O2. This immediate step not only keeps the electron transport chain moving but also creates the proton gradient that ultimately drives ATP synthesis and, downstream, NADPH formation. So the immediate consequence is water splitting by PSII producing O2, H+, and electrons.

More practice questions