Hydroxyl Group

This article is about the hydroxyl functional group. For the Hydroxyl radical, see Hydroxyl radical.


A hydroxyl is a chemical functional group containing an oxygen atom connected by a covalent bond to a hydrogen atom, a pairing that can be simply understood as a substructure of the water molecule. When it appears, it imparts to chemical structures some of the reactive and interactive properties of the -OH (not to be confused with the hydroxide ion OH-) of water (ionizability, hydrogen bonding, etc.). The neutral form of the hydroxyl group is a hydroxyl radical. The anion form, (OH) is called the hydroxide anion; it bears a single negative charge largely residing on the more electronegative oxygen.

Hydroxyl group

The hydroxyl group is prevalent in organic chemistry, where it is the defining functional group in alcohols. It appears throughout organic chemical structure and biochemical structure in sugars and some amino acids and phospholipids, and so in all biological barriers (biological membranes and cell walls). Hydroxyl groups belong to alcohol compounds such as ethanol C2H6O. Ethanol is present in alcoholic beverages. Hydroxyl groups can form hydrogen bonds with water molecules, helping to dissolve organic compounds such as sugars. It is typically a polar group as a result of the electrons spending more time near the electronegative oxygen atom.[1] One cannot overstate its centrality in all chemistry, especially because of its necessary targeting in organic synthesis, its roles in enzyme catalysis and inhibition, and in the formation of biological structures, all because of its hydrogen bonding capability. This capability underlies protein-ligand interactions, and imparts water solubility and internal structural stability to macromolecule

Hydroxyl radical

Main article: Hydroxyl radical

Hydroxyl radicals are highly reactive and undergo chemical reactions that make them short-lived. When biological systems are exposed to hydroxyl radicals, they can cause damage to cells, including those in humans, where they react with DNA, lipids, and proteins.

Lunar and other extraterrestrial observations

In 2009, India's Chandrayaan-1 satellite, NASA's Cassini spacecraft and the Deep Impact probe have each detected the presence of water by evidence of hydroxyl fragments on the Moon. As reported by Richard Kerr, "A spectrometer (the Moon Mineralogy Mapper, aka "M3"), detected an infrared absorption at a wavelength of 3.0 micrometers that only water or hydroxyl—a hydrogen and an oxygen bound together—could have created."[2] NASA also reported in 2009 that the LCROSS probe revealed an ultraviolet emission spectrum consistent with hydroxyl presence.[3] The Venus Express orbiter has been continuously sending back Venus science data since April 11, 2006. Results from Venus Express include the detection of hydroxyl in the atmosphere.

See also

References

Reece, Jane.Urry, Lisa.Cain, Michael.Wasserman, Steven.Minorsky, Peter.Jackson, Robert."Campbell Biology".Unit 1 Chapter 4. Ed. Susan Berge, Brandy Golden, and Logan Triglia. 9th Edition.San Francico. Text. 2011 ISBN 978-0-321-55823

External links

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.