Serine proteases such as Chymotrypsin are incredibly important to cellular metabolism as they facilitate the break down of enzymes into smaller peptides. These enzymes work through an 8-step mechanism in which a serine residue, with help of a histidine and aspartate, forms what is termed as a catalytic triad. The first step of chymotrypsin's mechanism is shown below. Tctrahedral Ir tom ediale Tolranodral Acy -enzyme intertaediate