cytosine

noun

cy·​to·​sine ˈsī-tə-ˌsēn How to pronounce cytosine (audio)
: 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 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 The molecule is made up of the chemical bases adenine, cytosine, guanine, and thymine—shortened to A, C, G, and T—which pair off to form a double helix. Emily Mullin, WIRED, 4 Dec. 2023 The molecules are called bases and are represented by the letters A (adenine), T (thymine), G (guanine), and C (cytosine). IEEE Spectrum, 22 Feb. 2016 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. Byrobert F. Service, science.org, 13 June 2023 Four chemical bases — adenine, guanine, cytosine, and thymine — bond with hydrogen to make base pairings. Emilie Le Beau Lucchesi, Discover Magazine, 15 Apr. 2022 Adenine bonds with thymine, and cytosine bonds with guanine. Olivia Munson, USA TODAY, 14 Feb. 2023 In all living things, DNA is naturally composed of four compounds, adenine, cytosine, guanine, and thymine. Carl Zimmer, Discover Magazine, 6 July 2011 Rather than inducing random changes in the virus’ RNA genome, the drug is more likely to cause specific nucleic acid substitutions, with guanine switching to adenine and cytosine to uracil. Byrobert F. Service, science.org, 1 Feb. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'cytosine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

1894, in the meaning defined above

Time Traveler
The first known use of cytosine was in 1894

Dictionary Entries Near cytosine

Cite this Entry

“Cytosine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cytosine. Accessed 28 Mar. 2024.

Kids Definition

cytosine

noun
cy·​to·​sine ˈsīt-ə-ˌsēn How to pronounce cytosine (audio)
: 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 How to pronounce cytosine (audio)
: a pyrimidine base C4H5N3O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, guanine, thymine, uracil

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