Plastocyanin then transports the two electrons to Photosystem I. Like photosystem II, the photosystem I complex contains an antenna for capturing light energy called the LHC.

Inside the photosystem I reaction center, each electron is re-engerized by the resonance energy from a photon of light. It is then transferred to ferredoxin, another mobile carrier (purple, bottom right).

Ferredoxin transfers each electron, one at a time, to Ferredoxin NADP Reductase, otherwise known as FNR (pink).

Once two electrons have been transferred to FNR, they are joined by a hydrogen ion and a molecule of NADP+. FNR then reduces NADP+ by adding to it the two electrons and one proton--creating NADPH.