In a laboratory experiment using spectrophotometry, an enzym…
In a laboratory experiment using spectrophotometry, an enzyme is combined with its substrate at time zero. The absorbance of the resulting solution is measured at time zero and at five-minute intervals. In this procedure, an increase in absorbance is related to the amount of product formed during the reaction. The experiment is conducted using the three preparations shown in the table below. Absorbance of Solution at different times Enzyme Preparation 0 min 5 min 10 min 15 min 20 min I. 3 mL of enzyme preparation 2 mL of substrate pH 5.0 0.0 0.22 0.33 0.38 0.37 II. 3 mL of boiled enzyme preparation 2 mL of substrate pH 5.0 0.0 0.06 0.04 0.03 0.04 What is the independent variable of this experiment?