LIFE 102 Lecture Notes - Lecture 18: Photosystem Ii, P680, Photosystem I
Document Summary
*two types of photosystems in the thylakoid membrane. Involves both photosystems and produces atp and nadph using light energy: photon hits a pigment and energy is passed among pigment molecules until it excites p680, excited electron from p680 is transferred to primary electron acceptor. P80 is a strong oxidizing agent: water is split by enzymes andd the electrons are transferred from the hydrogen atoms to p680+, thus reducing it to p680. P680 is the strongest known biological oxidizing agent. Diffusion of h+ (protons) across the membrane drives atp synthesis: in ps i (like ps ii), transferred light energy excites p700, which loses an electron to an electron acceptor. P700+ (which is missing an electron) accepts an electron passed down from. Ps ii via the electron transport chain: each electron falls down an electron transport chain of ps i to the protein ferredoxin (fd, the electrons are transferred to nadp+ and reduce it to nadph.
