
Amino acid | Definition, Structure, & Facts | Britannica
Dec 17, 2025 · Amino acid, any of a group of organic molecules that consist of a basic amino group, an acidic carboxyl group, and a unique organic side chain. The term amino acid is short …
Amino acid - Building Blocks, Structure, Functions | Britannica
Nov 22, 2025 · After they are incorporated into a peptide, the individual amino acids are referred to as amino acid residues. Small polymers of amino acids (fewer than 50) are called …
Structure and properties of amino acids | Britannica
amino acid, Any of a class of organic compounds in which a carbon atom has bonds to an amino group (―NH2), a carboxyl group (―COOH), a hydrogen atom (―H), and an organic side …
Protein - Amino Acids, Structure, Function | Britannica
Nov 29, 2025 · Although more than 100 amino acids occur in nature, particularly in plants, only 20 types are commonly found in most proteins. In protein molecules the α-amino acids are linked …
Amino acid - Reactions, Structure, Synthesis | Britannica
Dec 17, 2025 · Amino acid - Reactions, Structure, Synthesis: Amino acids via their various chemical functionalities (carboxyls, amino, and R groups) can undergo numerous chemical …
Acid | Definition, Examples, Types, Uses, & Facts | Britannica
Dec 12, 2025 · What are the 20 amino acid building blocks of proteins? What is the difference between standard and nonstandard amino acids?
What is an amino acid? | Britannica
An amino acid is an organic molecule that is made up of a basic amino group (−NH 2), an acidic carboxyl group (−COOH), and an organic R group (or side chain) that is unique to each amino …
amino acid - Students | Britannica Kids | Homework Help
Chemists define an amino acid as any group of organic molecules that consist of a basic amino group (–NH 2), an acidic carboxyl group (–COOH), and a specific organic side chain that is …
Amino acid - Origin, Life, Earth | Britannica
Nov 22, 2025 · Amino acid - Origin, Life, Earth: The question of why organisms on Earth consist of l-amino acids instead of d-amino acids is still an unresolved riddle.
Phenylalanine | Amino Acid, Protein, Metabolism | Britannica
Nov 4, 2025 · An amino acid is an organic molecule that is made up of a basic amino group (−NH 2), an acidic carboxyl group (−COOH), and an organic R group (or side chain) that is unique to …