| alanine | arginine |
| asparagine | aspartic acid |
| cysteine | dopa |
| gammaaminobutyric acid | glutamic acid |
| glutamine | glycine |
| histidine | homocysteine |
| isoleucine | leucine |
| lysine | methionine |
| ornithine | phenylalanine |
| proline | sarcosine |
| serine | taurine |
| threonine | tryptophan |
| tyrosine | valine |