cytosine

[sahy-tuh-seen, -zeen, -sin]

noun

Biochemistry.

1. a pyrimidine base, C 4 H 5 N 3 O, that is one of the fundamental components of DNA and RNA, in which it forms a base pair with guanine. C

cytosine

/ ˈsaɪtəsɪn /

noun

1. a white crystalline pyrimidine occurring in nucleic acids; 6-amino-2-hydroxy pyrimidine. Formula: C 4 H 5 N 3 O See also DNA RNA

cytosine

1. A pyrimidine base that is a component of DNA and RNA, forming a base pair with guanine. Chemical formula: C ₄ H ₅ N ₃ O.

Word History and Origins

Origin of cytosine¹

< German Cytosin (1894); cyto-, -ose ², -ine ²

Example Sentences

Importantly they also discovered all five nitrogenous bases — adenine, guanine, cytosine, thymine, and uracil — that are necessary to build DNA and RNA.

From Salon

These include 14 of the 20 amino acids that life on Earth uses to build proteins and all four of the ring-shaped molecules that make up DNA - adenine, guanine, cytosine and thymine.

From BBC

Nucleotides are composed of three distinctive parts: a sugar molecule, a phosphate group and one of the four nucleobases adenine, thymine, guanine and cytosine.

From Science Daily

For example, exposure to water can cause a chemical reaction called deamination that changes the nucleotide cytosine such that it appears to be the nucleotide thymine upon analysis.

From Scientific American

One loose end, Sasselov acknowledges, is that RAO has only been shown to lead to the synthesis of two of RNA’s four nucleotides, cytosine and uracil.

From Science Magazine