cytosine

noun

cy·​to·​sine ˈsī-tə-ˌsēn 

: a pyrimidine base C₄H₅N₃O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, guanine, thymine, uracil

Examples of cytosine in a Sentence

Recent Examples on the Web

Each bead is one of four different nucleotides: adenine, thymine, cytosine, or guanine, which biologists refer to by the letters A, T, C, and G. Strings of these nucleotides encode the building instructions and control switches for proteins and other molecules that do the work of maintaining life. —Michael C. Schatz, IEEE Spectrum, 27 June 2013

The key shows the universal elements (hydrogen, oxygen, carbon and nitrogen), the four bases of the DNA molecule (adenine, cytosine, guanine and thymine) with their molecular structure, where they’re placed in the DNA double helix, and how genes are arranged on a chromosome. —New Atlas, 19 Sep. 2024

Agilent developed a way to print strands of DNA from the four nucleic acid bases—cytosine (C), guanine (G), adenine (A), and thymine (T). —Phillip W. Barth, IEEE Spectrum, 25 Mar. 2024

This storage system works by converting digital information to the elements that make up DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). —Emma Roth, The Verge, 4 Dec. 2023

Word History

Etymology

International Scientific Vocabulary cyt- + -ose + -ine entry 2

First Known Use

1894, in the meaning defined above

Kids Definition

cytosine

noun

cy·​to·​sine ˈsīt-ə-ˌsēn 

: a chemical base that is a pyrimidine and codes genetic information in DNA and RNA compare adenine, guanine, thymine, uracil

Medical Definition

cytosine

noun

cy·​to·​sine ˈsīt-ə-ˌsēn 

: a pyrimidine base C₄H₅N₃O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, guanine, thymine, uracil