Catechol a natural substance found in plants reacts with oxygen to produce benzoquinone and water the reaction is catalyzed in plants by the enzyme polyphenol oxidase accumulation of benzoquinone in plant tissue results in the gradual appearance of a brown color a student observes that lemon juice PH 2 slows the browning of apple slices. The student claims that lemon juice slows the browning process by altering the activity of polyphenol oxidase. To test the claim, the student distributes equal amounts of a dilute catechol solution to 6 identical test tubes. The pH of each solution was adjusted as shown in the table, and the initial absorbance was recorded. Equal amounts of polyp were added to each reaction tube. After 10 minutes at room temperature the absorbance of 389 igh (A389) was measured for each sample. Solutions containing greater concentrations of benzoquinone absorb more light. The changes in A are shown in the table below. POLYPHENOL OXIDASE ACTIVITY
Test Tube pH Incubation with
A 1.0 0.06
B 3.0 0.09
C 5.0 0.23
D 7.0 0.83
E 9.0 0.32
F 11.0 0.10
A) On the axes provided, construct an appropriately labeled bar graph to analyze the effect of pH on polyphenol oxidase activity.
B) Based on the experimental results, estimate the optimal pH of the enzyme. Explain.