Michaelis Constant from Michaelis Menten kinetics equation Calculator

Michaelis Constant Formula:

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

Substrate Concentration (S):

mol/m³

Maximum Rate (V_max):

mol/m³·s

Initial Reaction Rate (V₀):

mol/m³·s

Michaelis Constant (K_M):

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1. What is Michaelis Constant?

Definition: The Michaelis Constant (K_M) 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:

\( K_M \) — Michaelis Constant (mol/m³)
\( S \) — Substrate Concentration (mol/m³)
\( V_{max} \) — Maximum Rate (mol/m³·s)
\( V_0 \) — Initial Reaction Rate (mol/m³·s)

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

3. Importance of Michaelis Constant

Details: A lower K_M 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 < V_max.

5. Frequently Asked Questions (FAQ)

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

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

Q3: Can K_M vary with different conditions?
A: Yes, K_M 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 K_M will have the same units as S.

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