Question

which of the following statements correctly describes an activity directly associated with photosystem i?
it produces atp by substrate - level phosphorylation.
it receives electrons from the electron transport chain associated with thylakoid membranes.
it produces o2.
it extracts hydrogen electrons released by the splitting of water.

Explanation:

• Statement 1: Photosystem I is not involved in substrate - level phosphorylation. Substrate - level phosphorylation occurs in processes like glycolysis and the citric acid cycle.
• Statement 2: In the light - dependent reactions of photosynthesis, electrons flow from photosystem II through an electron transport chain to photosystem I. So, photosystem I receives electrons from the electron transport chain associated with thylakoid membranes.
• Statement 3: The production of \(O_2\) is associated with photosystem II, where water is split.
• Statement 4: The extraction of electrons from water (splitting of water) occurs at photosystem II.

Answer:

It receives electrons from the electron transport chain associated with thylakoid membranes.