Hidroxilo: Diferenzas entre revisións
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==Radical hidroxilo==
O radical hidroxilo (·OH) é a forma neutra do ión hidróxido, polo que teñen un electrón menos ca este. Prodúcense pola descomposición de [[hidroperóxido]]s (ROOH) ou por [[fotólise]]. Os radicais hidróxido son enormemente reactivos, polo que duran moi pouco libres
| author=Sies, Helmut
| title=Strategies of antioxidant defense
| year=1993 | month=March | journal=European Journal of Biochemistry
| volume=215 | issue=2 | pages=213–219
| doi=10.1111/j.1432-1033.1993.tb18025.x
| pmid=7688300 }}</ref>), xa que reaccionan inmediatamente con outras substancias, e son moi importantes na química dos radicais.
Os radicais libres hidroxilo poden causar un dano oxidativo na célula, especialmente nos [[eritrocito]]s. Danan o [[ADN]], os [[lípido]]s, e [[proteína]]s, polo que son moi presudiciais.<ref>{{cite journal|pmc=88911|title=Antiseptics and Disinfectants: Activity, Action, and Resistance|year=1999|volume=12|issue=1|pmid=9880479|last1=McDonnell|first1=G|last2=Russell|first2=AD|pages=147–79|journal=Clinical microbiology reviews}}</ref> ▼
Mecanismos para eliminar os for scavenging peroxyl radicals for the protection of [[cell (biology)|cellular]] structures includes endogenous [[antioxidants]] such as [[melatonin]] and [[glutathione]], and dietary [[antioxidants]] such as [[mannitol]] and [[vitamin E]]. PMID 7776173.
== Biological significance ==
The hydroxyl radical can damage virtually all types of macromolecules: carbohydrates, nucleic acids ([[mutation]]s), lipids ([[lipid peroxidation]]) and amino acids (e.g. conversion of [[Phe]] to m-[[Tyrosine]] and o-[[Tyrosine]]). PMID 7776173. The hydroxyl radical has a very short ''[[in vivo]]'' [[half-life]] of approximately 10<sup>−9</sup> seconds and a high reactivity.<ref>{{cite journal
| author=Sies, Helmut
| title=Strategies of antioxidant defense
| year=1993 | month=March | journal=European Journal of Biochemistry
| volume=215 | issue=2 | pages=213–219
| doi=10.1111/j.1432-1033.1993.tb18025.x
| pmid=7688300 }}</ref> This makes it a very dangerous compound to the organism. PMID 7776173. PMID 9288572
Unlike [[superoxide]], which can be detoxified by [[superoxide dismutase]], the hydroxyl radical cannot be eliminated by an [[enzyme|enzymatic]] reaction. Mechanisms for scavenging peroxyl radicals for the protection of [[cell (biology)|cellular]] structures includes endogenous [[antioxidants]] such as [[melatonin]] and [[glutathione]], and dietary [[antioxidants]] such as [[mannitol]] and [[vitamin E]]. PMID 7776173.
▲Os radicais libres hidroxilo poden causar un dano oxidativo na célula, especialmente nos [[eritrocito]]s. Danan o [[ADN]], os [[lípido]]s, e [[proteína]]s, polo que son moi presudiciais.<ref>{{cite journal|pmc=88911|title=Antiseptics and Disinfectants: Activity, Action, and Resistance|year=1999|volume=12|issue=1|pmid=9880479|last1=McDonnell|first1=G|last2=Russell|first2=AD|pages=147–79|journal=Clinical microbiology reviews}}</ref>
Hai encimas no noso corpo como a [[glicosa-6-fosfato deshidroxenase]] (G6PD) que elimina os radicais hidroxilo libres antes de que fagan dano ás células.
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