Michaelis Menten Equation Calculator
Result
Reaction Velocity (v) 50.000 µmol/min
% of Vmax 50.0%
Note At [S]=Km: v = Vmax/2
Calculate the initial reaction velocity of an enzyme-catalyzed reaction using the Michaelis-Menten equation.
Formula
v = Vmax × [S] / (Km + [S])
- v = initial reaction velocity.
- Vmax = maximum velocity (achieved at saturating substrate).
- Km = Michaelis constant = [S] at v = Vmax/2 (related to enzyme affinity).
- Lower Km = higher enzyme affinity for substrate.
Vmax=100, Km=5 mM, [S]=5 mM
Inputs
- Vmax (maximum velocity): 100 µmol/min
- Km (Michaelis constant): 5 mM
- [S] Substrate Concentration: 5 mM
v = (100 × 5) / (5 + 5) = 500/10 = 50 µmol/min = 50% of Vmax.
Frequently asked questions
What does Km tell you?
Km is the substrate concentration at half-maximal velocity. Lower Km = higher affinity.
How do I find Vmax and Km experimentally?
Measure v at multiple [S] values and plot a Lineweaver-Burk double-reciprocal plot (1/v vs 1/[S]).