Summary:
- An amino acid is a compound that contains both an amino group (−NH2) and a carboxyl group (−COOH) in the same molecule.
- While any number of amino acids can possibly be imagined, biochemists generally reserve the term for a group of 20 amino acids which are formed and used by living organisms.
- Table below lists the names of the 20 naturally occurring amino acids along with a three-letter abbreviation.
- The advantage of this system comes when listing the amino acid sequence of a protein that may contain over 100 amino acids in its chain.