Electron transport chainElectron Transport Chain take place in the mitochondria. It is a collection of NADH which floats over the inner-membrane and enters the ETC at complex I, and the FADH2 enters the chain at complex II, these are known as electron carriers. The main function of the electron transport chain is to build up excess protons in the intermembrane space so that there will be a concentration gradient compared to the matrix of the mitochondria.
