Home Back

Catalytic rate constant given Michaelis Constant Calculator

Formula Used:

\[ k_{cat} = (K_M \times k_f) - k_r \]

mol/m³
1/s
mol/(m³·s)

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is Catalytic Rate Constant?

Definition: The Catalytic Rate Constant (kcat) is defined as the rate constant for conversion of the enzyme-substrate complex to enzyme and product.

Purpose: This calculator helps determine the catalytic efficiency of an enzyme based on Michaelis-Menten kinetics parameters.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ k_{cat} = (K_M \times k_f) - k_r \]

Where:

Explanation: The formula calculates the catalytic rate constant by accounting for both forward and reverse reaction rates in enzyme kinetics.

3. Importance of Catalytic Rate Constant

Details: kcat is crucial for understanding enzyme efficiency, determining turnover number, and comparing different enzymes' catalytic power.

4. Using the Calculator

Tips: Enter the Michaelis Constant (KM), forward rate constant (kf), and reverse rate constant (kr). All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for kcat?
A: kcat values typically range from 1 to 107 s-1, depending on the enzyme and reaction.

Q2: How does kcat relate to enzyme efficiency?
A: Higher kcat values indicate more efficient enzymes that convert substrate to product faster.

Q3: What if my reverse rate constant is zero?
A: If kr = 0, the calculation simplifies to kcat = KM × kf.

Q4: How do I measure these constants experimentally?
A: KM and kcat are typically determined through initial rate measurements at varying substrate concentrations.

Q5: What's the relationship between kcat and Vmax?
A: Vmax = kcat × [E]total, where [E]total is the total enzyme concentration.

Catalytic rate constant given Michaelis Constant Calculator© - All Rights Reserved 2025