Reactive oxygen species -ROS are produced by the oxidation-reduction
processes of some enzymes as a product of the energy metabolism of cells and
organelles and by exogenous sources. The mechanisms of oxidation-reduction and the
enzymatic kinetics of some ROS source enzymes are presented here, as well as the
mechanisms related to ROS production in organelles and cells and exogenous sources
such as Fe, Cd, Hg, Ni, Zn, among others and xenobiotics such as paraquat-PQ.
Keywords: Cytochrome C, Electron transfer, Enzymatic kinetics, Enzymatic
oxidation, Galactose Oxidase, Haber – Weiss reactions, Heavy metal
contamination, Microsomes, Paraquat, Reaction centre, Xanthine oxidase,
Xenobiotics.
