Editing Hydrogen peroxide (section)

===Fenton reaction===
The reaction of [[Ferrous|{{chem2|Fe(2+)}}]] and hydrogen peroxide is the basis of the [[Fenton reaction]], which generates [[hydroxyl radical]]s, which are of significance in biology:
:{{chem2|Fe(II) + H2O2 -> Fe(III)OH + HO*}}

The Fenton reaction explains the toxicity of hydrogen peroxides because the hydroxyl radicals rapidly and irreversibly oxidize all organic compounds, including [[protein]]s, [[membrane lipid]]s, and [[DNA]].<ref>Löffler G. and Petrides, P. E. ''Physiologische Chemie''. 4 ed., p. 288, Springer, Berlin 1988, {{ISBN|3-540-18163-6}} (in German)</ref> Hydrogen peroxide is a significant source of [[DNA damage (naturally occurring)|oxidative DNA damage]] in living cells. DNA damage includes formation of [[8-Oxo-2'-deoxyguanosine]] among many other altered bases, as well as strand breaks, inter-strand crosslinks, and deoxyribose damage.<ref name="Halliwell2021" /> By interacting with Cl<sup>−</sup>, hydrogen peroxide also leads to chlorinated DNA bases.<ref name="Halliwell2021">{{cite journal |vauthors=Halliwell B, Adhikary A, Dingfelder M, Dizdaroglu M |title=Hydroxyl radical is a significant player in oxidative DNA damage in vivo |journal=Chem Soc Rev |volume=50 |issue=15 |pages=8355–60 |date=August 2021 |pmid=34128512 |pmc=8328964 |doi=10.1039/d1cs00044f }}</ref> Hydroxyl radicals readily damage vital cellular components, especially those of the [[mitochondria]].<ref>{{cite journal |vauthors = Giorgio M, Trinei M, Migliaccio E, Pelicci PG |title = Hydrogen peroxide: a metabolic by-product or a common mediator of ageing signals? |journal = Nature Reviews. Molecular Cell Biology |volume = 8 |issue = 9 |pages = 722–8 |date = September 2007 |pmid = 17700625 |doi = 10.1038/nrm2240 |s2cid = 6407526 }}</ref><ref>{{cite journal |vauthors = Gonzalez D, Bejarano I, Barriga C, Rodriguez AB, Pariente JA |year = 2010 |title = Oxidative Stress-Induced Caspases are Regulated in Human Myeloid HL-60 Cells by Calcium Signal |journal = Current Signal Transduction Therapy |volume = 5 |issue = 2| pages = 181–6 |doi = 10.2174/157436210791112172}}</ref><ref>{{cite journal |vauthors = Bejarano I, Espino J, González-Flores D, Casado JG, Redondo PC, Rosado JA, Barriga C, Pariente JA, Rodríguez AB |display-authors = 6 |title = Role of Calcium Signals on Hydrogen Peroxide-Induced Apoptosis in Human Myeloid HL-60 Cells |journal = International Journal of Biomedical Science |volume = 5 |issue = 3 |pages = 246–256 |date = September 2009 |doi = 10.59566/IJBS.2009.5246 |pmid = 23675144 |pmc = 3614781}}</ref> The compound is a major factor implicated in the [[free-radical theory of aging]], based on its ready conversion into a [[hydroxyl radical]].