1. What is Substrate Concentration?

Definition: Substrate concentration is the number of moles of substrate per liter of solution in an enzyme-catalyzed reaction.

Purpose: This calculator helps determine the substrate concentration based on enzyme kinetics parameters.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula calculates substrate concentration from enzyme kinetics parameters, accounting for both the forward and reverse reactions.

3. Importance of Substrate Concentration

Details: Knowing substrate concentration is crucial for understanding reaction rates, enzyme efficiency, and designing biochemical experiments.

4. Using the Calculator

Tips: Enter all required rate constants and concentrations. Forward rate constant and catalyst concentration must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What are typical units for these parameters?
A: Rate constants typically use 1/s or mol/(m³·s), while concentrations use mol/m³.

Q2: How do I determine the rate constants experimentally?
A: Rate constants are typically determined through kinetic experiments measuring reaction rates at different substrate concentrations.

Q3: What's the difference between k_cat and k_f?
A: k_cat is the catalytic rate constant for product formation, while k_f is the forward rate constant for ES complex formation.

Q4: Can this be used for non-enzymatic catalysts?
A: Yes, the same principles apply to any catalytic system following Michaelis-Menten kinetics.

Q5: What if my enzyme concentration is very low?
A: The calculator remains valid, but experimental measurements at very low [E] may have higher relative errors.