An amino acid is a molecule containing an amine group, a carboxylic acid and a side chain, R, that varies depending on the amino acid.
General structure[]
The general chemical structure of an alpha amino acid.
Proteinogenic amino acids[]
These amino acids are used in proteins and divided up into essential and non-essential amino acids.
| Essential | Non-essential | ||
|---|---|---|---|
| Isoleucine |  |
Alanine |  |
| Leucine |  |
Arginine |  |
| Lysine |  |
Asparagine |  |
| Methionine* |  |
Aspartic acid |  |
| Phenylalanine |  |
Cysteine* |  |
| Threonine |  |
Glutamic acid |  |
| Tryptophan |  |
Glutamine |  |
| Valine |  |
Glycine |  |
| - | - | Histidine |  |
| - | - | Proline |  |
| - | - | Selenocysteine |  |
| - | - | Serine |  |
| - | - | Tyrosine |  |
- - These amino acids contain sulphur atoms.