Cytosine

Cytosine is a pyrimidine base found in DNA and RNA. In nucleosides and nucleotides, cytosine is linked to the sugar moiety via a covalent bond between nitrogen #1 of cytosine and carbon #1 of the sugar.

The ribonucleoside containing cytosine is called cytidine. The deoxyribonucleoside containing cytosine is called deoxycytidine.

See also: Figure 4.3, Figure 4.2, De Novo Pyrimidine Nucleotide Metabolism, Nucleotide Salvage Synthesis, Pyrimidine Catabolism