Bovine rhodopsin contains 348 amino acid residues. They can interact with cellular components including unsaturated lipids, amino acid residues and nucleic acids. These inhibitors modify key amino acid residues needed for enzymatic activity. Human Fpn consists of 571 amino acid residues. There are different hydrophobicity scales of amino acid residues. They have sugar chains (glycans) added to conserved amino acid residues. It consists of 209 amino acid residues. TDP-43 is 414 amino acid residues long. Proteins are usually ubiquinated at lysine residues. A linear chain of amino acid residues is called a polypeptide. Disulfide bonds in proteins are formed by oxidation of the sulfhydryl group of cysteine residues. This leads to the addition of seven amino acid residues to the normal LDH-H protein. HSP60s are barrel shaped and suited to bind to the hydrophobic residues of proteins. Generally proteins have a core of hydrophobic residues surrounded by a shell of hydrophilic residues. Chymotrypsin performs a hydrolysis reaction that cleaves after aromatic residues.