| Amino Acid | pKa (or none) | Functional Group |
| Lysine | |
| Threonine | |
| Phenylalanine | |
| Arginine | |
| Glutamine | |
| Tyrosine | |
| Primary amine of all AA | |
| Methionine | |
| Glycine | |
| Serine | |
| Histidine | |
| | Amino Acid | pKa (or none) | Functional Group |
| Proline | |
| Leucine | |
| Carboxylate of all single AA | |
| Cysteine | |
| Alanine | |
| Tryptophan | |
| Valine | |
| Isoleucine | |
| Glutamate | |
| Asparagine | |
| Aspartate | |
|