In a kinetic assay for enzyme activity the substrate is measured to have a change of 0.12 absorbance units per minute at 414 nm. The assay is conducted in a 0.4 cm pathlength cell. Given that e(414 nm) = 37,500 M^-1cm^-1 for the product, what is the rate in units of molar concentration per minute. It is customary in biological catalysis to write the initial rate as .

= ___________________________.