H2O2 + Fe2 ----> Fe3 + OH + OH-
Iron and Copper donate or accept free electrons during intracellular reactions and catalyze free-radical formation in (as in Fenton reaction) the human body.
Because most of the intraellular free iron is in the ferric (Fe3) state, it must first reduced to ferrous (Fe2) to participate in the Fenton reaction. This reduction can be enhanced by superoxide, and thus sources of iron and superoxide are required for maximal oxidative cell damage in the human body
Source(s):
Robbins and Cotran's Pathologic Basis of Disease
