8. Protein Function

Which amino acids in chymotrypsin's active site are critical participants in the cleavage of the substrate?

The following polypeptide N-G-I-F-D-A-Y-G-N-T-W-R-A-P-C-F-V-A is cleaved by chymotrypsin to produce multiple peptide fragments. Based on the specificity of chymotrypsin cleavage, how many peptide fragments are produced?

The activity of chymotrypsin drastically changes as the pH fluctuates in the relatively small range of pH 5-9. What amino acid residue in chymotrypsin's active site is most likely to be responsible for this effect of pH?