The electron transport chain is a series of complexes embedded in the inner mitochondrial membrane that transfer electrons from NADH and FADH2 to molecular oxygen via redox reactions. This video provides a brief introduction of electron transport chain and focuses on its individual complexes. Timeline: 00:02 introduction 01:21 membrane structure of the mitochondria 03:32 electron transport chain complexes 03:56 complex number I 05:09 complex number II 05:59 complex number III 06:48 complex number IV