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
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.
Glycine is an amino acid that can also act as an inhibitory neurotransmitter (a chemical messenger that calms brain activity). Ayesha Gulzar, Verywell Health, 21 July 2025 Rich in beneficial compounds such as amino acids, polyphenols, lecithin, gallic acid, and minerals such as calcium, magnesium, and potassium, Mucuna is used as a rejuvenating and aphrodisiac remedy in Ayurvedic medicine, and even to heal snake bites. Alessandra Signorelli, Glamour, 21 July 2025 New research reveals that a simple amino acid, serine, helps push stem cells to abandon hair growth in favor of wound healing, opening the door to new therapies for chronic wounds. New Atlas, 19 July 2025 Sequencing ancient proteins involves determining the order of amino acids in a sample. Katie Hunt, CNN Money, 15 July 2025 See All Example Sentences for amino acid

Word History

First Known Use

1897, in the meaning defined above

Time Traveler
The first known use of amino acid was in 1897

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Cite this Entry

“Amino acid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amino%20acid. Accessed 29 Jul. 2025.

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

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