Michaelis-Menten kinetics
The Michaelis-Menten equation describes the rate of enzymatic reactions. It relates reaction velocity to substrate concentration:
v = (Vmax × [S]) / (Km + [S])
- Vmax: Maximum reaction velocity (when enzyme is saturated)
- Km: Michaelis constant — [S] at which v = Vmax/2. Inversely related to enzyme affinity.
- [S]: Substrate concentration
Low vs. high substrate
- [S] << Km: Rate ≈ (Vmax/Km) × [S] — first-order kinetics
- [S] = Km: Rate = Vmax/2
- [S] >> Km: Rate ≈ Vmax — zero-order kinetics (saturated)