amino acid


Definition of amino acid

: an amphoteric organic acid containing the amino group NH2 especially : any of the various amino acids having the amino group in the alpha position that are the chief components of proteins and are synthesized by living cells or are obtained as essential components of the diet

Examples of amino acid in a Sentence

Recent Examples on the Web Researchers linked watermelon juice’s ability to relieve achy muscles to its L-citrulline content, which is an amino acid that helps to reduce muscle damage. Erica Sweeney, Good Housekeeping, 16 June 2022 That was true for mutations that changed an amino acid. John Timmer, Ars Technica, 11 June 2022 Perhaps beta-alanine [Ed: an amino acid that supposedly aids in the production of carnosine, a compound that plays a role in muscle endurance in high-intensity exercise] might help as well, but it’s not a muscle-building supplement per se. Oliver Lee Bateman, Men's Health, 19 May 2022 An amino acid concentrated in certain teas (such as green tea), L-theanine has been shown to promote alpha brain waves, which are the same relaxing waves that occur during meditation. Amy Capetta, Woman's Day, 19 May 2022 Most notably, a 2016 study examined eggshell fragments with burn marks collected from some 200 sites and analyzed the amino acid composition. Jennifer Ouellette, Ars Technica, 27 May 2022 There were also traces of an amino acid — glycine — adding weight to the idea that comets could be source of the building blocks of life. The Week Staff, The Week, 1 Oct. 2018 Copper tripeptide is a naturally occurring, brilliant blue amino acid complex that helps repair dry skin for a firmer and more youthful-looking complexion. Grooming Playbook, The Salt Lake Tribune, 5 Apr. 2022 Another database, UniProt, contains the amino acid sequences (without structures) for nearly two hundred million more proteins. Rob Toews, Forbes, 3 Oct. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'amino acid.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of amino acid

1897, in the meaning defined above

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Time Traveler for amino acid

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The first known use of amino acid was in 1897

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Last Updated

28 Jun 2022

Cite this Entry

“Amino acid.” Dictionary, Merriam-Webster, Accessed 29 Jun. 2022.

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More Definitions for amino acid

amino acid

ami·​no acid | \ ə-ˈmē-nō- \

Kids Definition of amino acid

: any of various acids containing carbon and nitrogen that are building blocks of protein and are made by living plant or animal cells or are obtained from the diet

amino acid


Medical Definition of amino acid

: an amphoteric organic acid containing the amino group NH2 especially : alpha-amino acid

More from Merriam-Webster on amino acid

Nglish: Translation of amino acid for Spanish Speakers Encyclopedia article about amino acid


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