role of oxygen in ETS
In the Electron Transport Chain (ETC) the electrons are passed sequentially from one carrier to the other and in the last to oxygen which results in formation of water.
In ETC the electrons which are produced by NADH pass sequentially through complex I, II, III, IV and V which are located in the inner membrane of mitochondria. In this process the oxygen act as the final electron acceptor and accepts hydrogen generated in the process to make water. This result in removal of the hydrogen from the system and the completes entire process. Thus, oxygen drives the completion of ETC.