Chapter 5, Problem 15TYK

A biologist performed two series of experiments on lactase, the enzyme that hydrolyzes lactose to glucose and galactose. First, she made up 10% lactose solutions containing different concentrations of enzyme and measured the rate at which galactose was produced (grams of galactose per minute). Results of these experiments are shown in Table A below. In the second series of experiments (Table B), she prepared 2% enzyme solutions containing different concentrations of lactose and again measured the rate of galactose production.

Table A Reaction Rate and Enzyme Concentration

Table B Reaction Rate and Substrate Concentration

a. Graph and explain the relationship between the reaction rate and the enzyme concentration.

b. Graph and explain the relationship between the reaction rate and the substrate concentration. How and why did the results of the two experiments differ?