Research Perspective Volume 1, Issue 8 pp 746—750

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.