Editing Reactive oxygen species (section)

{{short description|Highly reactive molecules formed from diatomic oxygen (O₂)}}
[[File:Reactive oxygen species (ROS) – some examples with Lewis structures.png|thumb|[[Lewis structure]] of some of the reactive oxygen species. <br>'''A''': hydroxyl radical ({{chem2|HO^{•} }}); <br>'''B''': hydroxide ion ({{chem2|HO-}}); <br>'''C''': singlet oxygen ({{chem2|^{1}O2 }}); <br>'''D''': superoxide anion ({{chem2|O2^{•–} }}); <br>'''E''': peroxide ion ({{chem2|O2(2-)}}); <br>'''F''': hydrogen peroxide ({{chem2|H2O2}}); <br>'''G''': nitric oxide ({{chem2|NO^{•} }})]]

In [[chemistry]] and [[biology]], '''reactive oxygen species''' ('''ROS''') are highly [[Reactivity (chemistry)|reactive]] chemicals formed from diatomic [[oxygen]] ({{chem2|O2}}), [[water]], and [[hydrogen peroxide]]. Some prominent ROS are [[hydroperoxide]] (H<sub>2</sub>O<sub>2</sub>), [[superoxide]] (O<sub>2</sub><sup>−</sup>),<ref>{{Cite journal |vauthors=Hayyan M, Hashim MA, AlNashef IM |date=March 2016 |title=Superoxide Ion: Generation and Chemical Implications |journal=Chemical Reviews |volume=116 |issue=5 |pages=3029–3085 |doi=10.1021/acs.chemrev.5b00407 |pmid=26875845 |doi-access=free}}</ref> [[hydroxyl radical]] (OH<sup>.</sup>), and [[singlet oxygen]](<sup>1</sup>O<sub>2</sub>).<ref name="Halliwell2021">{{Cite journal |vauthors=Halliwell B, Adhikary A, Dingfelder M, Dizdaroglu M |date=August 2021 |title=Hydroxyl radical is a significant player in oxidative DNA damage in vivo |journal=Chemical Society Reviews |volume=50 |issue=15 |pages=8355–8360 |doi=10.1039/d1cs00044f |pmc=8328964 |pmid=34128512}}</ref>  ROS are pervasive because they are readily produced from O<sub>2</sub>, which is abundant.  ROS are important in many ways, both beneficial and otherwise.  ROS function as signals, that turn on and off biological functions.  They are intermediates in the redox behavior of O<sub>2</sub>, which is central to [[fuel cell]]s.  ROS are central to the photodegradation of organic pollutants in the atmosphere.  Most often however, ROS are discussed in a biological context, ranging from their effects on aging and their role in causing dangerous genetic mutations.