Amino acid

Classification and structure of the amino acids

The different amino acids differ in the so called “sidechain” or “R group”. This determines the properties singular to each amino acid: polarity, electric charge, hydrophobicity, volume... It is important to understand these properties since they are the key to the structure and function of a protein.

The diagram groups the proteinogenic amino acids according to several physico-chemical properties. Clicking on the abbreviation for each one you will see its name, its official abbreviations and the three-dimensional model.


Criteria for this classification


Ionisation of amino acids


Beta- and gamma-amino acids