The primary structure of a protein — its amino acid sequence — drives the folding and intramolecular bonding of the linear amino acid chain, which ultimately determines the protein's unique ...

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.

will attract. This contributes to the folding of the enzyme molecule, its shape, and the shape of the active site. Changing the pH will affect the charges on the amino acid molecules.