# Electron Transport Chains --- **Electron transport chains** (ETCs) are a [[metabolism|metabolic]] process that generates large amounts of [[adenosine triphosphate]]. They located in membranes of cells or organelles. The ETC in the [[ETC (mitochondria)|mitochondria]] has four complexes. The ETC in the [[ETC (chloroplast)|chloroplasts]] are split in a couple different groups surrounding two different photosystems. It's also unique in that it uses a "noncyclic electron flow" which is signficant somehow. The ETC in [[ETC (bacterial)|bacteria]] vary wildely depending on what the individual bacteria uses as it's resources. ___