Figure 2.Diagram of reactive oxygen (ROS) formation.
Oxygen (O2) plays a major role in the formation of
ROS because O2 has unpaired electrons (represented by
single dots). When O2 picks up an electron, it becomes
superoxide, an extremely reactive anion. Superoxide dismutase
catalyzes the dismutation reaction of superoxide to hydrogen
peroxide, which is further catalyzed to the highly reactive hydroxyl
radical and ultimately to water by glutathione peroxidase and
catalase enzymes. Superoxide, hydrogen peroxide, and hydroxyl
radicals are considered to be ROS.
