BIO203H5 Lecture Notes - Lecture 6: Photosynthetic Reaction Centre, Photosystem Ii, Photosystem I

• School: UTM
• Department: Biology
• Course: BIO203H5
• Professor: Sanja Hinic- Frlog

Document Summary

Nutrient uptake: proton pumps (h+-atpase) establish a proton (or electrochemical) gradient, that supports entry of ions. Photon strikes chlorophyll transfer of energy to an electron in chlorophyll head excitation raise of electron to higher energy shell with greater potential energy. Chlorophyll absorbs red and blue photons electrons are raised to different states red photons raise electrons to state 1 higher-energy blue photons raise electrons to state 2. Green photons are of an intermediate energy level and are not easily absorbed by chlorophyll. Energy is transferred and electrons are effected when photons strike chlorophyll. Absorption -> transition from ground state to excited state. *fluorescence: absorbed energy is released as electromagnetic radiation. Photosynthetic pigments absorb light energy that powers photosynthesis. Absorption of photon -> transition from ground state to excited state: chl + h -> chl* Only 2% of red and blue photons absorbed by chlorophylls produce fluorescence. Pigments are arranged in photosystems to facilitate transfer of excitation energy.