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: The formula calculates the substrate concentration at which the reaction rate is half of Vmax.
Details: A lower KM indicates higher enzyme-substrate affinity. It's crucial for understanding enzyme efficiency and designing biochemical experiments.
Tips: Enter the substrate concentration, maximum rate, and initial reaction rate. All values must be > 0, and V0 must be < Vmax.
Q1: What does a high KM value indicate?
A: A high KM suggests low enzyme-substrate affinity, meaning the enzyme requires more substrate to reach half of its maximum rate.
Q2: How is KM related to enzyme efficiency?
A: Generally, enzymes with lower KM values are more efficient as they achieve higher reaction rates at lower substrate concentrations.
Q3: Can KM vary with different conditions?
A: Yes, KM can change with temperature, pH, and the presence of inhibitors or activators.
Q4: What units should I use for the inputs?
A: The calculator uses mol/m³ for concentration and mol/m³·s for reaction rates, but any consistent units can be used as KM will have the same units as S.
Q5: What if V0 equals Vmax?
A: This would make the denominator zero, which is mathematically undefined and biologically impossible as it would imply infinite enzyme-substrate affinity.