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.
But the production of melatonin relies on tryptophan, an amino acid that people need to get from nutrients because the body can’t produce them, said St-Onge, who is also a professor of nutritional medicine at Columbia University. Madeline Holcombe, CNN Money, 23 May 2025 This is due to its concentration of amino acids, especially leucine. Lindsey Desoto, Health, 20 May 2025 Taurine — an amino acid that occurs naturally in proteins like meat and fish — is a common ingredient in energy drinks like Red Bull. Cara Lynn Shultz, People.com, 16 May 2025 One of the explanations for why this bacterium may have survived centuries of insect evolution is tied to amino acids. Stephanie Edwards, Discover Magazine, 9 May 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

Browse Nearby Words

Cite this Entry

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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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