Section 5.4: Measurement of Km and Vmax
- The determination of the Km and Vmax values of an enzyme can be determined
from a plot of the initial velocity of the reaction for a range of substrate concentrations
- However, because the velocity curve is hyperbolic, it can be difficult to determine the
asymptote that defines Vmax and the halfway point that determines Km
- These days, a computer program can extrapolate the curve from a smaller number of data points,
but in the old days, a different method was used. This method involves plotting the reciprocal of
the velocity against the reciprocal of the substrate concentration, which gives a linear curve
instead of a hyperbolic one:
