MICROM 410 Lecture Notes - Lecture 8: Photophosphorylation, Photosystem Ii, Conjugated System
Document Summary
Electron ow is not cyclic, it is linear (z-form). Light is used to generate atp and nadh. Light rips an electron o the electron donor h2o (photolysis), and at the same time excites photosystem ii. The high energy electron is passed to the electron carriers present in the photosynthetic membranes. In plants and algae, this happens in chloroplasts (thylakoid membranes). Electron is ultimately dumped onto nad to produce reducing power. Atp synthase can be used to generate atp through non- cyclic photophosphorylation. Photosystem ii is sensitive to poisoning under the right environments (high sulfur environments). Cyanobacteria then will adapt to this by settling their photosystem solely around photosystem i. This is an adaptive situation in which the bacteria is using cyclic phosphorylation. High energy inorganic electron donors like elemental sulfur or sul de are used by these bacteria to replenish the lost electrons used to make reducing power. There are a couple of enzymes very speci c to this cycle:
