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Catalytic Rate Constant given Dissociation Rate Constant Calculator

Catalytic Rate Constant Formula:

\[ k_{cat} = \frac{V_0 \times (K_D + S)}{[E_0] \times S} \]

mol/m³·s
mol/m³
mol/m³
mol/m³
s⁻¹

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1. What is Catalytic Rate Constant?

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

Purpose: It measures the turnover number of an enzyme, indicating how many substrate molecules one enzyme molecule can convert to product per second.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ k_{cat} = \frac{V_0 \times (K_D + S)}{[E_0] \times S} \]

Where:

Explanation: The formula relates the initial reaction rate to enzyme and substrate concentrations, accounting for enzyme-substrate dissociation.

3. Importance of Catalytic Rate Constant

Details: kcat is crucial for understanding enzyme efficiency, comparing different enzymes, and predicting reaction rates under various conditions.

4. Using the Calculator

Tips: Enter all required values in appropriate units. Ensure substrate and enzyme concentrations are positive values.

5. Frequently Asked Questions (FAQ)

Q1: What does a high kcat value indicate?
A: A high kcat means the enzyme is very efficient, converting many substrate molecules per second.

Q2: How is kcat related to enzyme efficiency?
A: kcat is part of the catalytic efficiency measure (kcat/KM), where higher values indicate more efficient enzymes.

Q3: What are typical kcat values?
A: Most enzymes have kcat values between 1 and 10⁶ s⁻¹, with very efficient enzymes at the higher end.

Q4: Can kcat exceed 10⁶ s⁻¹?
A: Extremely rare, as this approaches the diffusion limit of molecular encounters in solution.

Q5: How does temperature affect kcat?
A: Like most rate constants, kcat typically increases with temperature up to the enzyme's denaturation point.

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