Editing Metabolism (section)

===Nucleotides===
{{Main|Nucleotide}}
The two nucleic acids, DNA and [[RNA]], are polymers of [[nucleotide]]s. Each nucleotide is composed of a phosphate attached to a [[ribose]] or [[deoxyribose]] sugar group which is attached to a [[nitrogenous base]]. Nucleic acids are critical for the storage and use of genetic information, and its interpretation through the processes of [[transcription (genetics)|transcription]] and [[protein biosynthesis]].<ref name="Nelson-2005"/> This information is protected by [[DNA repair]] mechanisms and propagated through [[DNA replication]]. Many [[virus]]es have an [[RNA virus|RNA genome]], such as [[HIV]], which uses [[reverse transcription]] to create a DNA template from its viral RNA genome.<ref>{{cite journal | vauthors = Sierra S, Kupfer B, Kaiser R | title = Basics of the virology of HIV-1 and its replication | journal = Journal of Clinical Virology | volume = 34 | issue = 4 | pages = 233–44 | date = December 2005 | pmid = 16198625 | doi = 10.1016/j.jcv.2005.09.004 }}</ref> RNA in [[ribozyme]]s such as [[spliceosome]]s and [[ribosome]]s is similar to enzymes as it can catalyze chemical reactions. Individual [[nucleoside]]s are made by attaching a [[nucleobase]] to a [[ribose]] sugar. These bases are [[heterocyclic]] rings containing nitrogen, classified as [[purine]]s or [[pyrimidine]]s. Nucleotides also act as coenzymes in metabolic-group-transfer reactions.<ref name="Wimmer-1978">{{cite journal | vauthors = Wimmer MJ, Rose IA | title = Mechanisms of enzyme-catalyzed group transfer reactions | journal = [[Annual Review of Biochemistry]] | volume = 47 | pages = 1031–78 | year = 1978 | pmid = 354490 | doi = 10.1146/annurev.bi.47.070178.005123 }}</ref>