Initial Rate of System of Competitive Inhibition of Enzyme Catalysis Calculator

Formula Used:

\[ V_0 = \frac{k_2 \times [E_0] \times S}{K_M \times (1 + \frac{I}{K_i}) + S} \]

Final Rate Constant (k₂):

s⁻¹

Initial Enzyme Concentration ([E₀]):

mol/m³

Substrate Concentration (S):

mol/m³

Michaelis Constant (K_M):

mol/m³

Inhibitor Concentration (I):

mol/m³

Enzyme Inhibitor Dissociation Constant (K_i):

mol/m³

Initial Reaction Rate (V₀):

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1. What is the Competitive Inhibition Equation?

The competitive inhibition equation calculates the initial reaction rate for enzyme-catalyzed reactions in the presence of a competitive inhibitor. It describes how an inhibitor competes with the substrate for the enzyme's active site, reducing the reaction rate.

2. How Does the Calculator Work?

The calculator uses the competitive inhibition equation:

\[ V_0 = \frac{k_2 \times [E_0] \times S}{K_M \times (1 + \frac{I}{K_i}) + S} \]

Where:

\( V_0 \) — Initial reaction rate (mol/m³·s)
\( k_2 \) — Final rate constant (s⁻¹)
\( [E_0] \) — Initial enzyme concentration (mol/m³)
\( S \) — Substrate concentration (mol/m³)
\( K_M \) — Michaelis constant (mol/m³)
\( I \) — Inhibitor concentration (mol/m³)
\( K_i \) — Enzyme inhibitor dissociation constant (mol/m³)

Explanation: The equation accounts for the effect of competitive inhibitors by modifying the Michaelis-Menten equation with an inhibition term.

3. Importance of Initial Reaction Rate Calculation

Details: Calculating the initial reaction rate is crucial for understanding enzyme kinetics, designing enzymatic reactions, and studying inhibitor effects in biochemical systems and drug development.

4. Using the Calculator

Tips: Enter all values in appropriate units (mol/m³ for concentrations, s⁻¹ for rate constant). All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is competitive inhibition?
A: Competitive inhibition occurs when an inhibitor molecule competes with the substrate for binding to the enzyme's active site, reducing the enzyme's efficiency.

Q2: How does competitive inhibition affect K_M and V_max?
A: Competitive inhibition increases the apparent K_M (makes it harder for substrate to bind) but does not affect the V_max (maximum reaction rate).

Q3: What are typical values for K_i?
A: K_i values vary widely depending on the enzyme and inhibitor, ranging from nanomolar to millimolar concentrations.

Q4: When is this equation applicable?
A: This equation applies to systems where the inhibitor binds reversibly to the enzyme's active site and follows Michaelis-Menten kinetics.

Q5: How can I distinguish competitive from non-competitive inhibition?
A: In competitive inhibition, V_max remains unchanged while K_M increases. In non-competitive inhibition, V_max decreases while K_M remains constant.