Catalase

one →Peroxidase, which catalyses the formation of oxygen and water from hydrogen peroxide (2 H2O2 → O2 + H2O = catalytic effect), but also acts peroxidatively (oxidises hydrogen donors). It is present in all human cells, particularly abundant in the liver (in so-called peroxysomes). Is effective as a H2O2 consumer in the antioxidative defense system against toxic O2 metabolites (e.g. for hemoglobin and other proteins).