Home Back

Michaelis Constant from Michaelis Menten kinetics equation Calculator

Michaelis Constant Formula:

\[ K_M = S \times \left( \frac{V_{max} - V_0}{V_0} \right) \]

mol/m³
mol/m³·s
mol/m³·s

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:

\[ K_M = S \times \left( \frac{V_{max} - V_0}{V_0} \right) \]

Where:

Explanation: The formula calculates the substrate concentration at which the reaction rate is half of Vmax.

3. Importance of Michaelis Constant

Details: A lower KM indicates higher enzyme-substrate affinity. It's crucial for understanding enzyme efficiency and designing biochemical experiments.

4. Using the Calculator

Tips: Enter the substrate concentration, maximum rate, and initial reaction rate. All values must be > 0, and V0 must be < Vmax.

5. Frequently Asked Questions (FAQ)

Q1: What does a high KM value indicate?
A: A high KM suggests low enzyme-substrate affinity, meaning the enzyme requires more substrate to reach half of its maximum rate.

Q2: How is KM related to enzyme efficiency?
A: Generally, enzymes with lower KM values are more efficient as they achieve higher reaction rates at lower substrate concentrations.

Q3: Can KM vary with different conditions?
A: Yes, KM can change with temperature, pH, and the presence of inhibitors or activators.

Q4: What units should I use for the inputs?
A: The calculator uses mol/m³ for concentration and mol/m³·s for reaction rates, but any consistent units can be used as KM will have the same units as S.

Q5: What if V0 equals Vmax?
A: This would make the denominator zero, which is mathematically undefined and biologically impossible as it would imply infinite enzyme-substrate affinity.

Michaelis Constant Calculator© - All Rights Reserved 2025