guanine

noun

gua·​nine ˈgwä-ˌnēn How to pronounce guanine (audio)
: a purine base C5H5N5O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, cytosine, thymine, uracil

Examples of guanine in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
According to new research, the secret to its distinctive hue lies in its tooth-like scales, called dermal denticles, which contain guanine crystals and melanosomes that reflect and absorb wavelengths respectively. Rosie McCall, Discover Magazine, 14 July 2025 Biology’s four bases—adenine (A), thymine (T), cytosine (C) and guanine (G)—encode the instructions that keep life alive. Andrew Whalen, Forbes.com, 9 July 2025 The metaphor leaps out: Like letters of the alphabet, molecules (the nucleotide bases A, T, C and G, for adenine, thymine, cytosine and guanine) are arranged into sequences — words, paragraphs, chapters, perhaps — in every organism, from bacteria to humans. Ingrid Wickelgren, Quanta Magazine, 5 Feb. 2025 The team also detected adenine, guanine, cytosine, thymine and uracil — all five of the biological nucleobases, or components that make up the genetic code in DNA and RNA. Ashley Strickland, CNN, 29 Jan. 2025 See All Example Sentences for guanine

Word History

Etymology

guano + -ine; from its being found especially in guano

First Known Use

1850, in the meaning defined above

Time Traveler
The first known use of guanine was in 1850

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Cite this Entry

“Guanine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/guanine. Accessed 22 Jul. 2025.

Kids Definition

guanine

noun
gua·​nine ˈgwän-ˌēn How to pronounce guanine (audio)
: a purine base that codes genetic information in DNA and RNA compare adenine, cytosine, thymine, uracil

Medical Definition

guanine

noun
gua·​nine ˈgwän-ˌēn How to pronounce guanine (audio)
: a purine base C5H5N5O that codes genetic information in the polynucleotide chain of DNA or RNA compare adenine, cytosine, thymine, uracil

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