The final electron acceptor in cyclic photophosphorylation is _________.

Verified step by step guidance

1. Understand the process of cyclic photophosphorylation, which occurs in the light reactions of photosynthesis, specifically in photosystem I.
2. Recall that in cyclic photophosphorylation, electrons are excited by light energy and passed through a series of electron carriers in the electron transport chain.
3. Note that unlike non-cyclic photophosphorylation, the electrons do not reduce NADP+ to NADPH but instead return to the original photosystem I reaction center.
4. Identify that the final electron acceptor in cyclic photophosphorylation is the molecule that receives the electrons after they have passed through the electron transport chain and before they return to photosystem I.
5. Conclude that since the electrons cycle back to photosystem I, the final electron acceptor is actually the photosystem I reaction center itself.

Key Concepts

Cyclic Photophosphorylation

Cyclic photophosphorylation is a process in photosynthesis where electrons are excited by light and cycle back to the original photosystem, generating ATP without producing NADPH or oxygen.

Electron Transport Chain in Photosynthesis

The electron transport chain in photosynthesis transfers electrons through a series of carriers, creating a proton gradient that drives ATP synthesis; in cyclic photophosphorylation, electrons return to the photosystem instead of reducing NADP+.

Final Electron Acceptor in Cyclic Photophosphorylation

In cyclic photophosphorylation, the final electron acceptor is the original photosystem (usually Photosystem I), which receives the electrons after they pass through the electron transport chain, allowing the cycle to continue.