Michaelis-Menten Calculator
Calculate the rate of enzyme-catalyzed reactions (v) from substrate concentration [S], maximum velocity (Vmax), and the Michaelis constant (Km).
Kinetic Constants & Concentration
Enter maximum velocity, Km constant, and current substrate concentration.
Reaction Velocity (v)
Ftional Active-Site Saturation (v / V_max)
Km Significance
When [S] = Km, the reaction rate is exactly 50% of Vmax. Lower Km values indicate higher substrate binding affinity.
Substrate Ratio ([S] / Km) vs. Velocity (% Vmax) Reference Table
| Substrate Concentration Ratio | Ftional Saturation (Y) | Percentage of Vmax (% Vmax) | Kinetic Regime |
|---|---|---|---|
| [S] = 0.1 × Km | 0.091 | 9.1% | First-order kinetics (v ∝ [S]) |
| [S] = 1.0 × Km | 0.500 | 50.0% | Half-maximal velocity midpoint |
| [S] = 2.0 × Km | 0.667 | 66.7% | Sub-saturation regime |
| [S] = 10.0 × Km | 0.909 | 90.9% | Near zero-order kinetics (v ≈ Vmax) |
Calculation Methodology & Equations
Michaelis-Menten Equation
Relates initial reaction velocity v to substrate concentration [S], maximum velocity Vmax, and Michaelis constant Km.
Ftional Saturation (Y)
Represents the percentage of enzyme active sites occupied by substrate molecules in solution.
Frequently Asked Questions
What is Michaelis Constant (Km)? ▼
Km is the substrate concentration at which the reaction rate is half of maximum velocity (1/2 Vmax). It serves as an inverse measure of enzyme-substrate affinity.
What does Vmax represent? ▼
Vmax is the theoretical maximum reaction rate reached when all enzyme active sites are saturated with substrate ([S] >> Km).
What is Ftional Saturation? ▼
Ftional saturation (Y = v / Vmax = [S] / (Km + [S])) measures the proportion of enzyme active sites bound to substrate at any given substrate concentration.
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