1. What is Reverse Rate Constant?

Definition: The Reverse Rate Constant (k_r) is the rate constant for the backward reaction in enzyme kinetics.

Purpose: It helps quantify how quickly the enzyme-substrate complex dissociates back into free enzyme and substrate.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( k_r \) — Reverse rate constant (mol/m³·s)
• \( k_f \) — Forward rate constant (s⁻¹)
• \( E \) — Catalyst concentration (mol/m³)
• \( S \) — Substrate concentration (mol/m³)
• \( ES \) — Enzyme-substrate complex concentration (mol/m³)
• \( k_{cat} \) — Catalytic rate constant (s⁻¹)

Explanation: The formula calculates the reverse rate constant by accounting for the forward reaction and catalytic conversion.

3. Importance of Reverse Rate Constant

Details: Understanding k_r is crucial for determining enzyme efficiency, reaction equilibrium, and designing enzyme inhibitors.

4. Using the Calculator

Tips: Enter all required values in appropriate units. All concentrations must be positive, and rate constants non-negative.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for k_r?
A: Values vary widely but often range from 10⁻³ to 10³ s⁻¹ depending on the enzyme and substrate.

Q2: How does k_r relate to enzyme affinity?
A: Higher k_r values indicate weaker enzyme-substrate binding (lower affinity).

Q3: Can k_r be negative?
A: No, if you get a negative result, check your input values as this indicates an error.

Q4: What's the difference between k_r and k_cat?
A: k_r describes substrate release, while k_cat describes product formation.

Q5: How is this used in drug design?
A: Drugs often aim to modify k_r to either enhance or inhibit enzyme activity.