photosystem IImedical dictionary

<plant biology> Photosynthetic system in chloroplasts in which light of up to 680 nm is absorbed and its energy used to split water molecules, giving rise to a high energy reductant, Q and oxygen.

The reductant is the starting point for an electron transport chain that leads to photosystem I and that is coupled to the phosphorylation of ADP to ATP.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)