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

One pair of under-eye patches taps 1,254 self-dissolving microneedles to deeply deliver the anti-aging ingredients including hyaluronic acid, daisy flower and amino acids. —Celia Shatzman, Forbes, 26 Nov. 2024

Isoleucine is one of the three branched-chain amino acids (BCAAs). —Elizabeth Barnes, Verywell Health, 26 Nov. 2024

Turkey famously contains an amino acid called tryptophan, which helps your body produce serotonin and melatonin, which regulate sleep-wake cycles. —Caroline Hopkins Legaspi, New York Times, 25 Nov. 2024

This is because the amino acids (including lysine) that form protein are abundant in most protein-rich food sources such as eggs, meat like pork, beef, chicken and fish, and dairy such as milk, yogurt and cheese. —Daryl Austin, USA TODAY, 19 Nov. 2024

Word History

First Known Use

1897, in the meaning defined above

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