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{{Nukleobasa, nukleosida, dan nukleotida}}
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==History==
Cytosine was discovered and named by [[Albrecht Kossel]] and Albert Neumann in 1894 when it was hydrolyzed from calf [[thymus]] tissues.<ref>A. Kossel and Albert Neumann (1894) [http://gallica.bnf.fr/ark:/12148/bpt6k90735d/f437.image.langEN "Darstellung und Spaltunsprodukte der Nucleïnsäure (Adenylsäure)"] (Preparation and cleavage products of nucleic acids (adenic acid)), ''Berichte der Deutschen Chemischen Gesellschaft zu Berlin'', '''27''' : 2215-2222. The name "cytosine" is coined on page 2219: ''" … ein Produkt von basischen Eigenschaften, für welches wir den Namen "Cytosin" vorschlagen."'' ( … a product with basic properties, for which we suggest the name "cytosine".)</ref><ref>{{cite journal | author = Kossel, A.; Steudel, H. Z. | journal = Physiol. Chem. | year = 1903 | volume = 38 | pages = 49 | doi = 10.1515/bchm2.1903.38.1-2.49 | title = Weitere Untersuchungen über das Cytosin}}</ref> A structure was proposed in 1903, and was synthesized (and thus confirmed) in the laboratory in the same year.
Cytosine recently found use in [[quantum computation]]. The first time any [[quantum]] mechanical properties were harnessed to process [[information]] took place on August 1 in 1998 when researchers at Oxford implemented [[David Deutsch|David Deutsch's]] [[Deutsch-Jozsa algorithm|algorithm]] on a two [[qubit]] [[nuclear magnetic resonance]] quantum computer (NMRQC) based on cytosine.<ref>{{cite journal | last = Jones | first = J.A. |author2=M. Mosca | title = Implementation of a quantum algorithm on a nuclear magnetic resonance quantum computer | journal = J.Chem.Phys | volume = 109| issue = 109 | pages = 1648–1653 | publisher = | date = 1998-08-01 | url = http://www.citebase.org/abstract?id=oai%3AarXiv.org%3Aquant-ph%2F9801027 | doi = 10.1063/1.476739 | id = | accessdate = 2007-10-18 }}</ref>
==Chemical reactions==
[[File:Cytosine chemical structure.svg|thumb|left|100px|Cytosine with numbered components. [[Methylation]] occurs on carbon nr 5.]]
Cytosine can be found as part of DNA, as part of RNA, or as a part of a [[nucleotide]]. As [[cytidine triphosphate]] (CTP), it can act as a co-factor to enzymes, and can transfer a phosphate to convert [[adenosine diphosphate]] (ADP) to [[adenosine triphosphate]] (ATP).
In DNA and RNA, cytosine is paired with [[guanine]]. However, it is inherently unstable, and can change into [[uracil]] ([[deamination|spontaneous deamination]]). This can lead to a [[point mutation]] if not repaired by the [[DNA repair]] [[enzyme]]s such as uracil glycosylase, which cleaves a uracil in DNA.
Cytosine can also be [[Methylation|methylated]] into [[5-Methylcytosine|5-methylcytosine]] by an enzyme called [[DNA methyltransferase]] or be methylated and [[Hydroxylation|hydroxylated]] to make [[5-Hydroxymethylcytosine|5-hydroxymethylcytosine]].
Active enzymatic deamination of cytosine or 5-methylcytosine by the [[APOBEC]] family of cytosine deaminases could have both beneficial and detrimental implications on various cellular processes as well as on organismal evolution.<ref name="Chahwan">{{cite journal| author= Chahwan R., Wontakal S.N., and Roa S.| title=Crosstalk between genetic and epigenetic information through cytosine deamination| journal=Trends in Genetics| volume = 26| pages = 443–448| year = 2010 | doi = 10.1016/j.tig.2010.07.005| pmid = 20800313| issue = 10}}</ref> The implications of deamination on 5-hydroxymethylcytosine, on the other hand, remains less understood.
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==Referensi==
{{Reflist}}
==Pranala luar dan Kutipan ==
{{Commons category|Cytosine}}
* [http://gmd.mpimp-golm.mpg.de/Spectrums/04ef65b4-ae00-4bbf-b115-64d1aa7e0fcd.aspx Cytosine MS Spectrum]
*{{EINECSLink|200-749-5}}
* {{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|url=http://www.pnas.org/cgi/content/full/96/8/4396 |pmc=16343 }}
{{Nucleobases, nucleosides, and nucleotides}}
[[Category:Basa nukleat]]
[[Category:Amina]]
[[Category:Pyrimidones]]
[[Kategori:DNA]]
[[Kategori:Basa organik]]
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