Organelle where H2O2 is produced and destroyed is-

Cells have developed many mechanisms to remove free radicals and thereby minimize injury. Free radicals are inherently unstable and decay spontaneously. There are also nonenzymatic and enzymatic systems that contribute to inactivation of free radicals . * The rate of decay of superoxide is significantly increased by the action of superoxide dismutases (SODs) found in many cell types. Glutathione (GSH) peroxidases are a family of enzymes whose major function is to protect cells from oxidative damage. The most abundant member of this family, glutathione peroxidase 1, is found in the cytoplasm of all cells. It catalyzes the breakdown of H2O2 by the reaction 2 GSH (glutathione) + H2O2 - GS-SG + 2 H2O. The intracellular ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH) is a reflection of this enzyme's activity and thus of the cell's ability to catabolize free radicals. * Catalase, present in peroxisomes, catalyzes the decomposition of hydrogen peroxide (2H2O2 - O2 + 2H2O). It is one of the most active enzymes known, capable of degrading millions of molecules of H2O2 per second. * Endogenous or exogenous antioxidants (e.g., vitamins E, A, and C and b-carotene) may either block the formation of free radicals or scavenge them once they have formed. Robbins 9 th edition page no. 15