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

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1. Step 1: Analyze Table A to understand the relationship between enzyme concentration and reaction rate. Notice that as enzyme concentration increases (from 0% to 8%), the reaction rate also increases (from 0 to 200 grams of galactose per minute). This suggests a direct relationship between enzyme concentration and reaction rate.
2. Step 2: Create a graph for Table A. Plot enzyme concentration on the x-axis and reaction rate on the y-axis. Use the data points (0%, 0), (1%, 25), (2%, 50), (4%, 100), and (8%, 200) to construct the graph. The graph should show a positive correlation, indicating that higher enzyme concentrations lead to faster reaction rates.
3. Step 3: Interpret the graph for Table A. The graph demonstrates that the reaction rate increases proportionally with enzyme concentration, which aligns with the principle that more enzyme molecules can catalyze more substrate molecules, increasing the rate of product formation.
4. Step 4: Compare the results of Table A with Table B. In Table B, the reaction rate increases with lactose concentration up to 20%, but plateaus at 65 grams of galactose per minute beyond this point. This indicates that the enzyme becomes saturated with substrate at higher lactose concentrations, and the reaction rate cannot increase further.
5. Step 5: Explain the biological significance. The results from Table A show that enzyme concentration is a limiting factor for the reaction rate when substrate is abundant. Table B highlights the concept of enzyme saturation, where all active sites of the enzyme are occupied, and adding more substrate does not increase the reaction rate. Together, these findings illustrate key principles of enzyme kinetics.