PSI (680nm)

• photosystem I has a chlorophyll a primary pigment molecule with an absorption peak of 700nm
• 1. the chlorophyll a molecule emits electrons if enough light energy reached the antenna complex 
• 2. these electrons are trapped by another electron acceptor and subsequently passed in to NADP to form NADPH
• 3. to provide the hydrogen necessary to reduce NADP, the electrons combine with the hydrogen ions provided from photolysis which occurred in photosystem II
• 4. electrons lost from the chlorophyll a are replaced by electrons passing down the electron chain, electrons that originated from photosystem II
• 5. the end products are ATP and NADPH, both utilised in the light independent reaction