Living organisms have evolved protecting systems to protect themselves against oxidative stress and to prevent damage from these toxic agents. They have developed several enzymatic and non-enzymatic mechanisms to detoxify these very active compounds. Enzymatically, oxygen radicals are removed mainly by the action of four enzymes: superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Superoxide dismutases (SODs) are metalloenzymes that catalyze the conversion of superoxide molecules to hydrogen peroxide and molecular oxygen and therefore form one of the cell’s major defense mechanisms against oxidative stress. This review will discuss superoxide dismutase, structure function and mechanism

Keywords: Superoxide dismutase; Free radicals; Oxidative stress; Enzymes; Metalloenzymes.