Often, oxygen is reduced to either water (cytochrome oxidase of the mitochondrial electron transfer chain) or hydrogen peroxide (dehydrogenation of fatty acyl-CoA in peroxisomes).
The name "mixed-function oxidase" indicates that the enzyme oxidizes two different substrates simultaneously.
Desaturation of fatty acyl-CoA in vertebrates is an example of the mixed-function oxidase reaction.
The mixed-function oxidase reaction proceeds as follows: AH + BH2 + O2 --> AOH + B + H2O (H2O as catalyst.)
High levels of mixed-function oxidase activity have been studied for their activation effects in human colon carcinoma cell lines,[2] to study the susceptibility to certain cancers.