<P> Hydrogen peroxide is formed in human and animals as a short - lived product in biochemical processes and is toxic to cells . The toxicity is due to oxidation of proteins , membrane lipids and DNA by the peroxide ions . The class of biological enzymes called SOD ( superoxide dismutase ) is developed in nearly all living cells as an important antioxidant agent . They promote the disproportionation of superoxide into oxygen and hydrogen peroxide , which is then rapidly decomposed by the enzyme catalase to oxygen and water . </P>
where does hydrogen peroxide come from in the body
nearly all living cells