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

/ sī′tə-sēn′ /

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

In DNA, these bases are adenine, cytosine, guanine and thymine.

From Science News For Students

Researchers have also seen hints of uracil, but cytosine and thymine remained elusive, until now.

From Science News