For the wild type (unmutated) enzyme, you measure a rate of p-nitrophenol release by the change in absorbance at 405 nm (for the slower phase only) of 0.216 (in a cuvette with a pathlength of 1 cm) over the course of two minutes. Use the Beer-Lambert Law to calculate the concentration of product released over this time; the extinction coefficient of p-nitrophenol at 405 nm is 18,000 M-1 cm-1.