23. The activity of chymotrypsin changes as the pH changes in the range of pH 5-9, as shown on the following graph. 100 Percent activity (%) gg 50 40 60 60 80 20 20 0 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 рН From your understanding of the chemical mechanism of the chymotrypsin reaction, and making the simplifying assumption that the only titratable groups are in the catalytic triad, explain the pH effect on chymotrypsin activity by answering parts a, b, and c. a. What amino acid functional group on which residue is most likely responsible for the effect of pH? b. What is the apparent pK₁ of that functional group? Indicate on the graph how you deduced the pKa. c. Briefly explain in terms of the chymotrypsin mechanism why the activity increases as the pH increases in this pH range.