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amino acid
noun
: 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
Matcha boasts a boost of antioxidants and the amino acid L-Theanine, which is thought to promote relaxation and jitter-free, sustained energy.
—Kate Kassin, Bon Appétit, 26 Feb. 2024
It’s formulated with hyaluronic acid for hydration, marshmallow root sustainably sourced from Albania to deliver antioxidants and violet rice water rich in B vitamins and amino acids.
—Celia Shatzman, Forbes, 26 Feb. 2024
When combined with other molecules, HCN can help form nucleobases and amino acids, the precursors to more complex biochemistry such as proteins and RNA.
—Ling Xin, Scientific American, 14 Dec. 2023
Some of those found at Clarkia include lignin, which is the structural support tissue of plants, lipids like fats and waxes, and possibly DNA and amino acids.
—Robert Patalano, Discover Magazine, 9 Feb. 2024
The code was incomplete, a sequence of programming phrases that bracketed a partial map of nucleic acids, amino acid chains, and proteins.
—Elliot Ackerman, WIRED, 5 Feb. 2024
The team noticed that, in particular, the free radicals reacted with cysteine, an amino acid used in protein production.
—Christian Thorsberg, Smithsonian Magazine, 18 Jan. 2024
Elevated levels of that amino acid are correlated to a higher risk for dementia, heart disease, and stroke, per Cleveland Clinic.
—Sean Evans, Robb Report, 14 Jan. 2024
In particular, cow milk protein has the highest amount of branched-chain amino acids compared to other foods.6
Eggs
Eggs also top the list of complete protein sources.
—Cynthia Sass, Mph, Rd, Health, 9 Nov. 2023
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'amino acid.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Word History
First Known Use
1897, in the meaning defined above
Dictionary Entries Near amino acid
Cite this Entry
“Amino acid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amino%20acid. Accessed 19 Mar. 2024.
Kids Definition
amino acid
noun
ami·no acid
ə-ˈmē-nō-
: any of numerous acids that include some which are the building blocks of proteins and are made by living cells from simpler compounds or are obtained in the diet
Medical Definition
amino acid
noun
: 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
Britannica.com: Encyclopedia article about amino acid
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