Citosina: Diferenzas entre revisións
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Liña 1:
{{chembox
| verifiedrevid = 443557332
| ImageFile1 = Cytosine_chemical_structure.png
| ImageSize1 = 120px
| ImageFile2 = Cytosine-3D-balls.png
| ImageSize2 = 180px
| ImageFile3 = Cytosine-3D-vdW.png
| ImageSize3 = 150px
| IUPACName=4-aminopirimidin-2(1''H'')-ona
| OtherNames=4-amino-1''H''-pirimidina-2-ona
| Section1= {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 577
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 15913
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C4H5N3O/c5-3-1-2-6-4(8)7-3/h1-2H,(H3,5,6,7,8)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = OPTASPLRGRRNAP-UHFFFAOYSA-N
| CASNo=71-30-7
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem=597
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 8J337D1HZY
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 16040
| SMILES = c1cnc(=O)[nH]c1N
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C00380
| InChI = 1/C4H5N3O/c5-3-1-2-6-4(8)7-3/h1-2H,(H3,5,6,7,8)
| InChIKey = OPTASPLRGRRNAP-UHFFFAOYAY
| MeSHName=Cytosine
}}
|Section2 = {{Chembox Properties
| Formula=C<sub>4</sub>H<sub>5</sub>N<sub>3</sub>O
| MolarMass=111,10 g/mol
| Appearance=
| Density= 1,55 g/cm<sup>3</sup> (calculada)
| MeltingPt = 320-325ºC
| Melting_notes = descomp.
| BoilingPt=
| pKa=4,45 (secundaria), 12,2 (primaria)<ref>{{cite book | author = Dawson, R.M.C., et al. | title = Data for Biochemical Research | location = Oxford | publisher = Clarendon Press | year = 1959}}</ref>
| Solubility=
}}
|Section3= {{Chembox Hazards
| MainHazards=
| FlashPt=
| Autoignition=
}}
}}
A '''citosina''' é unha das cinco [[base nitroxenada|bases nitroxenadas]] que forman parte dos ácidos nucleicos ([[ácido desoxirribonucleico|ADN]] e [[ácido ribonucleico|ARN]]) e no [[código xenético]] represéntase coa letra C. As outras catro bases son a [[adenina]], a [[guanina]], a [[timina]] e o [[uracilo]]. A citosina no ADN sempre se emparella coa guanina.
Forma os nucleósidos '''[[citidina]]''' (Cyd) e '''[[desoxicitidina]]''' (dCyd), e os nucleótidos '''[[CMP|citidilato]]''' (CMP) e '''[[desoxicitidina monofosfato|desoxicitidilato]]''' (dCMP).
Liña 8 ⟶ 57:
A citosina foi descuberta en [[1894]] cando foi illada en tecido do [[timo]] de carneiro.
==Notas==
{{Listaref}}
{{Ácidos nucleicos}}
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