The following table gives the structures (including charge) of the acid and conjugate base forms of organic functional groups present in amino acids.
| Group Name | Acid Form | Base Form |
|---|---|---|
| Carboxylate | -COOH | -COO-1 |
| Amine | -NH4+1 | -NH3 |
| Alcohol | -OH | -O-1 |
| Thiol | -SH | -S-1 |