66.6667
µmol/min
100
%
66.6667
µmol/min
100
%
The Michaelis-Menten Calculator computes the reaction velocity of an enzyme-catalyzed reaction based on substrate concentration, the maximum velocity (Vmax), and the Michaelis constant (Km). This fundamental equation of enzyme kinetics describes how reaction rate varies with substrate concentration in a hyperbolic relationship.
Understanding Michaelis-Menten kinetics is essential in biochemistry, pharmacology, and biotechnology. It helps determine enzyme efficiency, design drug dosing regimens, and optimize industrial enzyme processes. The calculator also shows the fraction of enzyme active sites occupied by substrate.
The Michaelis-Menten equation describes the relationship between reaction rate and substrate concentration:
v = (Vmax × [S]) / (Km + [S])
Where Vmax is the maximum rate when all enzyme is saturated, Km is the substrate concentration at half-maximal velocity, and [S] is the substrate concentration. The saturation level is:
Saturation (%) = [S] / (Km + [S]) × 100
At [S] = Km, the velocity equals exactly half of Vmax and saturation is 50%.
Inputs
Results
At [S] = 2 × Km, the enzyme operates at 66.7% of its maximum velocity. The hyperbolic curve is starting to plateau at this concentration.
Inputs
Results
At [S] = 10 × Km, the enzyme is 91% saturated and the velocity is close to Vmax. Further increases in substrate will have diminishing effects on rate.
Km reflects the affinity of an enzyme for its substrate. A low Km means the enzyme reaches half-maximal velocity at a low substrate concentration, indicating high affinity. A high Km indicates low affinity, requiring more substrate to achieve the same rate. Km is an intrinsic property of each enzyme-substrate pair.
The model assumes a single substrate, no product inhibition, steady-state conditions, and no cooperativity. It does not apply to allosteric enzymes with sigmoidal kinetics, multi-substrate reactions, or conditions where substrate inhibition occurs. In such cases, modified equations like the Hill equation are needed.
Traditionally, they are determined by measuring initial velocities at different substrate concentrations and fitting the data. The Lineweaver-Burk (double-reciprocal) plot linearizes the equation for graphical determination. Modern approaches use nonlinear regression fitting directly to the Michaelis-Menten equation.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
How helpful was this calculator?
Be the first to rate!
