Final answer:
NADP reductase is not involved in establishing conditions for ATP synthesis; rather, it is involved in forming NADPH during photosynthesis. ATP synthase, Photosystem I, and the Cytochrome complex contribute directly to the creation of a proton gradient or ATP synthesis through chemiosmosis.
Step-by-step explanation:
The complex not involved in establishing conditions for ATP synthesis is NADP reductase. NADP reductase is the enzyme involved in the final step of the light reactions of photosynthesis, specifically the transfer of electrons to NADP+ to form NADPH. In contrast, complexes such as Photosystem I, ATP synthase, and the Cytochrome complex play direct roles in the creation of a proton gradient or direct synthesis of ATP through chemiosmosis.
For instance, ATP synthase (b) facilitates the conversion of ADP to ATP using the proton motive force generated across the thylakoid membrane, while the Cytochrome complex (c) helps establish the proton gradient during electron transport. Photosystem I contributes to the restart of the electron transport chain by accepting electrons that have lost energy during their passage through the chain.