Home Back

Michaelis Constant given Maximum Rate at Low Substrate Concentration Calculator

Michaelis Constant Formula:

\[ K_M = \frac{V_{max} \times [S]}{V_0} \]

mol/m³·s
mol/m³
mol/m³·s
mol/m³

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is Michaelis Constant?

Definition: The Michaelis Constant (KM) is numerically equal to the substrate concentration at which the reaction rate is half of the maximum rate of the system.

Purpose: It's a key parameter in enzyme kinetics that indicates the affinity of an enzyme for its substrate.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ K_M = \frac{V_{max} \times [S]}{V_0} \]

Where:

Explanation: This formula calculates KM from measurable kinetic parameters at low substrate concentrations.

3. Importance of Michaelis Constant

Details: KM is crucial for understanding enzyme efficiency, designing experiments, and predicting enzyme behavior under different conditions.

4. Using the Calculator

Tips: Enter the maximum rate (Vmax), substrate concentration ([S]), and initial reaction rate (V0). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does a low KM value indicate?
A: A low KM indicates high enzyme-substrate affinity, meaning the enzyme reaches half its maximum velocity at low substrate concentrations.

Q2: How is Vmax determined experimentally?
A: Vmax is determined by measuring reaction rates at increasing substrate concentrations until the rate plateaus.

Q3: What units should I use for inputs?
A: The calculator uses mol/m³·s for rates and mol/m³ for concentrations, but any consistent unit system will work.

Q4: Can this calculator be used for inhibitor studies?
A: Yes, but be aware that different inhibitor types affect KM and Vmax differently.

Q5: What's a typical range for KM values?
A: KM values vary widely but typically range from 10-6 to 10-2 M for most enzymes.

Michaelis Constant Calculator© - All Rights Reserved 2025