What is Electron Transport?
In celleular respiration (that’s in animals), the electrons come from NADH and FADH (which is produced by glycolysis and the citric acid cycle). The electron is passed down the electron transport chain (ETC) during oxidative phosporylation, releasing energy step by step and pumping h+ against its gradient (from the mitochondial matrix to the intermembrane space in the mitochondria), which in turn helps synthesize ATP when it moves back down its gradient. In the light reactions of photosynthesis (pants!): in photosystem II, WATER is split into 2H+, O, and **2 electrons** which replace the electrons lost in the chlorophyll a (P680) molecules. After light hits the P680 and boosts the two electrons up to the primary acceptor, they will travel down the ETC, causing a release in energy and production of ATP. At the end of the chain is… photosystem I’s chlorophyll a (P700) molecule!! It also gets an electron, and after absorbing some light, they too get boosted up to the primary acceptor an
