Reduction of Oxygen

∞ generated and posted on 2016.12.09 ∞

Generation of metabolic water as the last step of cellular respiration such as occurs in mitochondria.

Reduction of Oxygen occurs in association with oxidation of hydrogen, that is, with the electrons of two hydrogens partially donated to an all too willingly receptive oxygen, thus creating water (H2O).

In acting as the final electron acceptor of cellular respiration, a.k.a., oxidative phosphorylation, molecular oxygen receives electrons from the electron transport chain and thus is reduced. This reduction involves accepting not just electrons but also hydrogen ions, two of each per oxygen atom. That is,

     2O2 + 4H+ + 4e- → 2H2O


     ½O2 + 2H+ + 2e- → 2H2O

The resulting H2O is otherwise dubbed metabolic water and can be a significant source of water to bodies.

Reduction of oxygen takes place in the mitochondrial matrix and thus contributes to the proton motive force by sequestering protons on that side of the mitochondrial inner membrane where already there is a dearth of protons.