Serine proteases are a type of enzyme that are diversely spread throughout all kingdoms of life. Their function is to cleave a bond in a peptide via hydrolysis. Typically, they are endoproteases, meaning they work in the middle of a peptide chain. Additionally, they are allosteric enzymes. This means that their function and activity can be controlled by an effector molecule that induces a conformational shape change in the enzyme. Their name is derived from the serine amino acid and its side chain that plays an important role in its function that resides in the enzyme active site.