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

Protein provides the amino acids necessary for muscle building, immune function, creating hormones and neurotransmitters, and many other critical processes.13 Milk is a complete protein source that provides all nine essential amino acids, which can only be obtained through the diet. —Jillian Kubala, Health, 28 Feb. 2025

Lean Poultry The amino acids in protein from foods help form the hormones and neurotransmitters involved in the body's stress response. —Heather Jones, Verywell Health, 26 Feb. 2025

Mica adds a light-reflecting sheen, tapioca starch absorbs excess oil, and pearl extract delivers amino acids to help moisturize and refresh hair. —Deanna Pai, Allure, 21 Feb. 2025

Not all incomplete proteins have the same limiting amino acid or acids. —Caroline Tien, SELF, 31 Jan. 2025

Word History

First Known Use

1897, in the meaning defined above

Rhymes for amino acid

• antacid
• placid

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