Question

Oxygen is critical for aerobic respiration. Explain its role with respect to ETS.

Answer 1

In the Electron Transport System, NADH + H⁺ and FADH₂ are energy carriers to produce ATP. Electrons are transferred through a sequence of events and finally to the oxygen molecule. The oxygen molecule works like the final acceptor of hydrogen to form water molecules. Although oxygen comes at the end, it is critical for aerobic respiration. Oxidative phosphorylation involves a chain of events in which electrons are transferred through an electron gradient. Phosphorylation is like the flow of water through a tap. Until the tap is not open to allow the first drop of water, subsequent drops of water cannot flow down.

Oxygen acting as a hydrogen acceptor is like a receptacle collecting the first electron so.

It is possible to maintain the subsequent flow of electrons through ETS. Hence, oxygen is necessary to create a gradient through which electrons can be transferred passively.