<prompt> Role of molecular oxygen in ETC isTransfer of reducing equivalent to CoQTransfer of reducing equivalent from cytosol to mitochondriaTo act as electron acceptorGeneration of ATP  <response>: As it turns out, the reason you need oxygen is so your cells can use this molecule during oxidative phosphorylation, the final stage of cellular respiration. ... Oxygen sits at the end of the electron transpo chain, where it accepts electrons and picks up protons to form water 