Michaelis-Menten Kinetics Calculator

Calculate enzyme reaction rates (v) from substrate concentration, Vmax, and Km.

Enter your experimental or literature values to determine enzyme velocity using the Michaelis-Menten equation. Optionally, solve for substrate concentration given a target velocity.

Examples

See how to use the Michaelis-Menten equation with real-world data.

Standard Michaelis-Menten Calculation

Standard Michaelis-Menten Calculation

Calculate reaction rate for given substrate, Vmax, and Km.

[S] (Substrate, mM): 2.5 mM

Vmax (μmol/min): 10 μmol/min

Km (mM): 1.2 mM

Low Substrate Concentration

Low Substrate Concentration

Calculate rate when substrate is much lower than Km.

[S] (Substrate, mM): 0.2 mM

Vmax (μmol/min): 8 μmol/min

Km (mM): 1 mM

High Substrate Concentration

High Substrate Concentration

Calculate rate when substrate is much higher than Km.

[S] (Substrate, mM): 10 mM

Vmax (μmol/min): 12 μmol/min

Km (mM): 2 mM

Solve for Substrate Needed for Target Rate

Solve for Substrate Needed for Target Rate

Find the substrate concentration needed to reach a target velocity.

[S] (Substrate, mM): undefined mM

Vmax (μmol/min): 15 μmol/min

Km (mM): 3 mM

Target v (μmol/min): 7.5 μmol/min

Other Titles
Understanding Michaelis-Menten Kinetics: A Comprehensive Guide
Master the principles, calculations, and applications of the Michaelis-Menten equation in enzyme kinetics.

What is the Michaelis-Menten Equation?

  • Definition and Origin
  • Key Parameters: Vmax and Km
  • Why Use Michaelis-Menten Kinetics?
The Michaelis-Menten equation models the rate of enzymatic reactions as a function of substrate concentration. It is fundamental in biochemistry for understanding enzyme efficiency and substrate affinity.
The Michaelis-Menten Equation

Examples of Michaelis-Menten Kinetics

  • At [S] = Km, the reaction rate is half of Vmax.
  • If [S] >> Km, the rate approaches Vmax.

Step-by-Step Guide to Using the Calculator

  • Input Data Collection
  • Calculation Process
  • Interpreting Results
To use the calculator, enter substrate concentration, Vmax, and Km. Optionally, enter a target velocity to solve for required substrate. The calculator computes the reaction rate and percent of Vmax achieved.
Calculation Steps

Step-by-Step Examples

  • Input [S] = 2.5 mM, Vmax = 10 μmol/min, Km = 1.2 mM.
  • The calculator computes v and percent of Vmax.

Real-World Applications of Michaelis-Menten Kinetics

  • Enzyme Research
  • Pharmaceutical Development
  • Clinical Diagnostics
Michaelis-Menten kinetics are used in enzyme research, drug development, and clinical diagnostics to analyze enzyme efficiency, compare inhibitors, and optimize reaction conditions.
Applications in Science and Medicine

Application Examples

  • Comparing Km values to assess enzyme-substrate affinity.
  • Determining Vmax to evaluate enzyme efficiency.

Common Misconceptions and Correct Methods

  • Misinterpreting Km and Vmax
  • Incorrect Unit Usage
  • Ignoring Substrate Saturation
Common mistakes include confusing Km with enzyme affinity, using inconsistent units, or neglecting the effect of high substrate concentrations. Always ensure units are consistent and understand the meaning of each parameter.
Avoiding Calculation Errors

Misconception Examples

  • Using Km in μM but [S] in mM.
  • Assuming Vmax is reached at low substrate concentrations.

Mathematical Derivation and Examples

  • The Michaelis-Menten Formula
  • Solving for Substrate Concentration
  • Worked Example Calculations
The Michaelis-Menten equation: v = (Vmax × [S]) / (Km + [S]). To solve for [S] given v: [S] = (v × Km) / (Vmax - v).
Example Calculation

Mathematical Examples

  • Given [S] = 2.5 mM, Vmax = 10 μmol/min, Km = 1.2 mM: v = (10 × 2.5) / (1.2 + 2.5) = 6.76 μmol/min.
  • To reach v = 5 μmol/min with Vmax = 10 μmol/min, Km = 1.2 mM: [S] = (5 × 1.2) / (10 - 5) = 1.2 mM.