Michaelis Constant Formula:
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Definition: The Michaelis Constant (KM) is numerically equal to the substrate concentration at which the reaction rate is half of the maximum rate of the system.
Purpose: It's a key parameter in enzyme kinetics that indicates the affinity of an enzyme for its substrate.
The calculator uses the formula:
Where:
Explanation: This formula calculates KM from measurable kinetic parameters at low substrate concentrations.
Details: KM is crucial for understanding enzyme efficiency, designing experiments, and predicting enzyme behavior under different conditions.
Tips: Enter the maximum rate (Vmax), substrate concentration ([S]), and initial reaction rate (V0). All values must be > 0.
Q1: What does a low KM value indicate?
A: A low KM indicates high enzyme-substrate affinity, meaning the enzyme reaches half its maximum velocity at low substrate concentrations.
Q2: How is Vmax determined experimentally?
A: Vmax is determined by measuring reaction rates at increasing substrate concentrations until the rate plateaus.
Q3: What units should I use for inputs?
A: The calculator uses mol/m³·s for rates and mol/m³ for concentrations, but any consistent unit system will work.
Q4: Can this calculator be used for inhibitor studies?
A: Yes, but be aware that different inhibitor types affect KM and Vmax differently.
Q5: What's a typical range for KM values?
A: KM values vary widely but typically range from 10-6 to 10-2 M for most enzymes.