What is Cytosine?
{{Chembox new |ImageFile=Cytosine_chemical_structure.png |ImageSize=120px |IUPACName=4-amino-3H-pyrimidin-2-one |OtherNames= |Section1= {{Chembox Identifiers | CASNo=71-30-7 | PubChem=597 | SMILES=C1=C(NC(=O)N=C1)N | MeSHName=Cytosine }} |Section2= {{Chembox Properties | Formula=C<sub>4</sub>H<sub>5</sub>N<sub>3</sub>O | MolarMass=111.102 | Appearance= | Density= | MeltingPt=320 - 325°C (decomp) | BoilingPt= | Solubility= }} |Section3= {{Chembox Hazards | MainHazards= | FlashPt= | Autoignition= }} }} '''Cytosine''' is one of the 5 main [[nucleobase]]s used in storing and transporting [[genetics|genetic]] information within a [[cell]] in the [[nucleic acid]]s [[DNA]] and [[RNA]]. In DNA and RNA, cytosine is paired with [[guanine]]. However, it is unstable, and can change into [[uracil]]. This can lead to a [[point mutation]] if not repaired. The [[DNA repair]] [[enzymes]], such as uracil glycosylase, cuts uracil in DNA. Cytosine is the centre of modern genetic research into [[epigenetics]]. [[Methyl]] groups added to cytosine change the action of genes during lifetime. These changes are not inherited.<ref>Carey, Nessa 2011. ''The epigenetics revolution: how modern biology is rewriting our understanding of genetics, disease and inheritance''. London: Icon Books. ISBN 978-184831347-7</ref> == References == {{reflist}} ==Other websites== *[http://www.compchemwiki.org/index.php?title=Cytosine Computational Chemistry Wiki] {{Webarchive|url=https://web.archive.org/web/20051202071659/http://www.compchemwiki.org/index.php?title=Cytosine |date=2005-12-02 }} * {{cite journal |author=Shapiro R |title=Prebiotic cytosine synthesis: a critical analysis and implications for the origin of life |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=96 |issue=8 |pages=4396–401 |year=1999 |pmid=10200273 |doi= 10.1073/pnas.96.8.4396|pmc=16343 |doi-access=free }} [[Category:Organonitrogen compounds]] [[Category:DNA]] [[Category:Epigenetics]]