Question

question 16 of 25
which is a role of photosystem ii in the light reactions?
a. making nadph
b. making adp
c. splitting h₂o
d. making nadp+

Explanation:

Photosystem II (PSII) is involved in the light - dependent reactions of photosynthesis. One of its key functions is the splitting of water (\(H_2O\)). When light is absorbed by PSII, it provides the energy to split water molecules. This process releases electrons (which are used in the electron - transport chain), protons (\(H^+\)), and oxygen (\(O_2\)).

• Option A: NADPH is made in the light reactions, but it is mainly associated with the electron - transport chain after photosystem I (PSI) and the enzyme NADP⁺ reductase, not directly with PSII's main role.
• Option B: ADP is not made by PSII. In fact, ADP is converted to ATP (not the other way around) in the light reactions through processes like chemiosmosis.
• Option D: \(NADP^+\) is a reactant in the formation of NADPH and is not made by PSII. PSII's role is more about the initial steps of the light reactions involving water splitting rather than \(NADP^+\) production.

Answer:

C. Splitting H₂O