Outputs of noncyclic photophosphorylation What are the net end products generated by noncyclic electron flow during the light reactions of photosynthesis?

Introduction / Context:
Noncyclic photophosphorylation transfers electrons from water to NADP+, generating both a proton gradient and reducing power. Recognizing the trio of outputs is essential for connecting the light reactions to the Calvin cycle and overall plant metabolism.

Given Data / Assumptions:

• PSII oxidizes water, producing O2 and protons.
• Electron transport and cytochrome b6f generate a proton gradient for ATP synthesis.
• PSI and ferredoxin NADP+ reductase reduce NADP+ to NADPH.

Concept / Approach:

The net outcome of linear electron flow is oxygen evolution, ATP formation, and NADPH production. These products are then used in carbon fixation and other biosynthetic reactions in the stroma.

Step-by-Step Solution:

Verification / Alternative check:

Chlorophyll fluorescence, oxygen electrode measurements, and NADP+ reduction assays demonstrate simultaneous O2 release, ATP formation, and NADPH accumulation under noncyclic conditions.

Why Other Options Are Wrong:

Options listing CO2 or H2 are unrelated to the light reaction outputs. Water, ADP, and NADP+ are substrates or oxidized forms, not products. ATP alone is characteristic of cyclic flow, not noncyclic.

Common Pitfalls:

Confusing ATP-only production of cyclic flow with the full product set of noncyclic flow.

Final Answer:

O2, ATP and NADPH