Light Dependent Reactions

The light dependent reactions take place in and around the thylakoid membrane of the granna.

In chloroplasts the photosynthetic pigments (chlorophylla, chlorophyllb and caratinoids) are clustered in membrane bound structures called the photosystem I (PSI) and photosystem II (PSII).

Electrons are transported from PSII to PSI via the electron transport chain.

The electron transport chain also translocates protons from the stroma into the intrathylakoid space. The ATP synthase is responsible for the synthesis of ATP via a mechanism called "chemiosmosis."