pOxygen is an essential molecule in the production of adenosine triphosphate ATP in cells, and a lack of energy due to O2 deficiency makes the maintenance of biological functions and human life improbable. Since oxygen functions as the final electron acceptor in the series of ATP synthesis reactions in conjunction with oxidative phosphorylation in mitochondria, its deficiency causes the oxidation of a series of coenzymes, such as nicotinamide and flavin adenine dinucleotide, and the reduction in oxygen molecules to water molecules Hsub2subO. Persistent deficiency has been believed to cause a loss of biological functions, even resulting in death. This classical view of oxygen has been completely revised over the last 20 years. Mammals do not have a mechanism for biosynthesizing oxygen in their bodies. In higher organisms such as vertebrates, which possess many organs, oxygen in the body is always scarce, therefore, the dominant view is that organisms have evolved mechanisms to respond t