Abstract
The enzymatic and non-enzymatic reaction mechanisms of primary and secondary defense systems developed by cells to diminish the effects caused by overproduction of reactive oxygen species-ROS as a metabolic response to the damaging effects from endogenous and environmental factors are presented here. Enzymatic reaction mechanisms developed by plants as an antioxidant defense system are also presented.
Keywords: Antioxidants, Catalase, Coenzyme Q-CoQ, Cu-ZnSOD, Glutathione, HNE, Plant antioxidant defense, Superoxide dismutase-SOD, Trapping free radicals, UCPs, Vitamin C, Vitamin E.