uracil

noun

ura·​cil ˈyu̇r-ə-ˌsil How to pronounce uracil (audio)
-səl
: a pyrimidine base C4H4N2O2 that is one of the four bases coding genetic information in the polynucleotide chain of RNA compare adenine, cytosine, guanine, thymine

Examples of uracil in a Sentence

Recent Examples on the Web With that sample, scientists have found evidence suggesting that asteroids had delivered water to the early Earth, and discovered the presence of uracil — a building block of RNA, a molecule that helps form proteins. Katrina Miller, New York Times, 25 Sep. 2023 Meanwhile, scientists studying samples returned from the near-Earth asteroid Ryugu discovered vitamin B3 and an RNA compound called uracil. Ashley Strickland, CNN, 25 Mar. 2023 The molecules include uracil, a building block for RNA, as well as niacin, which is important to metabolism, ScienceAlert writes. Devika Rao, The Week, 22 Mar. 2023 Then, the team detected the signatures of uracil, niacin and other organic compounds containing nitrogen. Ashley Strickland, CNN, 21 Mar. 2023 Researchers just announced the discovery of the nucleobase uracil—one of the building blocks of RNA—in a sample from the asteroid Ryugu. Jackie Appel, Popular Mechanics, 21 Mar. 2023 Maybe an adenine gets swapped with a uracil (a substitution mutation that could also occur with any of the base pairs), or perhaps one or more bases get inserted or deleted. Quanta Magazine, 25 Feb. 2021 In the case of SARS-CoV-2, which has an RNA genome based on adenine, cytosine, guanine and uracil, sometimes mistakes happen. Quanta Magazine, 25 Feb. 2021 However, rather than the conventional duo of base pairs, adenine and uracil or cytosine and guanine, the molecules form hexamers, or six-membered rings. Quanta Magazine, 5 Feb. 2014

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'uracil.' 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 ur- entry 1 + acetic + -il (substance relating to)

First Known Use

1890, in the meaning defined above

Time Traveler
The first known use of uracil was in 1890

Dictionary Entries Near uracil

Cite this Entry

“Uracil.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/uracil. Accessed 19 Mar. 2024.

Kids Definition

uracil

noun
ura·​cil ˈyu̇r-ə-ˌsil How to pronounce uracil (audio)
-səl
: a pyrimidine base that is one of the four bases coding hereditary information in RNA compare adenine, cytosine, guanine, thymine

Medical Definition

uracil

noun
: a pyrimidine base C4H4N2O2 that is one of the four bases coding genetic information in the polynucleotide chain of RNA compare adenine, cytosine, guanine, thymine

More from Merriam-Webster on uracil

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!