Concept #2: Chymotrypsin's Active Site

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

Practice: 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?

Practice: 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?