The amino acid cysteine has a chemically reactive side chain that can form bonds with another cysteine. Amino acids can also be basic, like lysine, or acidic, like glutamic acid. The sequence and ...

In addition, pyrrolysine, used in the biosynthesis of proteins in some archaea and bacteria but not present in humans, and selenocysteine, a cysteine analogue only ... and an organic side chain (also ...

These amino acids can be classified based on various criteria, such as their essentiality, polarity, and side chain properties ... aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, ...