Determination of K1. (A) Intensity of light transmitted through the assay mixture plotted as a function of time at different concentrations of glucose. The transmittance through a cuvette (L=0.2 cm) is monitored every 1 s for 2000 s at λmax=571 nm; the data points are plotted in steps of 50 s for clarity (the confidence band interval is kept at 1 s). Each measurement is performed three times; the data show the average of the three trials. (B) Concentration of resorufin plotted as a function of time using Eq. (5) (symbols). A non-linear first order kinetic model was used to fit the data (solid lines).