hydroxyl

__Hydroxyl__ Hydroxyl is a chemical functional group that is comprised of an oxygen atom covalently bonded to a hydrogen atom. It is the defining functional group in alcohols. In its anion form, it is call Hydroxide and has an overall charge of (-1). Hydroxl appears throughout organic molecular structure. It appears in sugars and amino acids as well as cell walls.

(OH-) = Hydroxide

Hydroxyl radical
Hydroxyl radicals are highly reactive and undergo [|chemistry] that makes them short-lived. On generation in or exposure of biological systems to these radicals, they can cause damage to cells, including those in humans, where they react with DNA, lipids, and proteins.

The **hydroxyl radical**, **•OH**, is the neutral form of the [|hydroxide ion] (OH–). Hydroxyl radicals are highly reactive and consequently short-lived; however, they form an important part of [|radical chemistry]. Most notably hydroxyl radicals are produced from the decomposition of [|hydroperoxides] (ROOH) or, in [|atmospheric chemistry], by the reaction of [|excited] [|atomic oxygen] with water. It is also an important radical formed in radiation chemistry, since it leads to the formation of hydrogen peroxide and oxygen, which can enhance [|corrosion] and [|SCC] in coolant systems subjected to radioactive environments. Hydroxyl radicals are also produced during UV-light dissociation of H2O2 (suggested in 1879) and likely in [|Fenton chemistry], where trace amounts of reduced transition metals catalyze peroxide-mediated oxidations of organic compounds.

Hydroxyl group
The hydroxyl group is prevalent in [|organic chemistry], where it is the defining [|functional group] in [|alcohols] ( [|ethanol] , [|methanol] , etc.), appearing pervasively throughout organic chemical structure ( [|natural products] , [|drugs] , etc.) and biochemical structure—in [|sugars] ( [|saccharides] ), and in some [|amino acids] and [|phospholipids] , and so in all biological barriers (bio [|membranes] and [|cell walls] ). One cannot overstate its centrality in all chemistry, especially because of its necessary targeting in [|organic synthesis], and its roles in [|enzyme] [|catalysis] and [|inhibition] , and in the formation of biological structures, both via its [|hydrogen bonding] capability. This capability underlies [|protein-ligand interactions], and imparts water solubility and internal structural stability to [|macromolecules] , etc.