Enzyme catalysis: the active site and the rate law

The active site shows the catalytic triad of a real serine protease with its hydrogen bonds measured. Kinetics lets you play with the Michaelis–Menten equation and watch K_M, V_max, and catalytic efficiency emerge.

Active-site structure: bovine α-chymotrypsin in complex with the inhibitor eglin c, PDB 1ACB (chymotrypsinogen numbering: catalytic triad Ser195–His57–Asp102). The two triad hydrogen bonds are computed live from the deposited coordinates. Kinetics: the steady-state Michaelis–Menten law v = V_max·[S]/(K_M + [S]), with V_max = k_cat·[E] and [E] fixed at 1 µM; the diffusion-limit ceiling on k_cat/K_M is ≈10⁸–10⁹ M⁻¹s⁻¹.