Question 11 pts
When chymotrypsin is assayed with the surrogate substratep-nitrophenylacetate, a rapid burst of colored productformation (p-nitrophenolate) is observed, corresponding toa relatively steep slope on the A410 vs. time (seconds)plot, followed by a slower-but-steady release ofp-nitrophenolate, corresponding to a relatively less-steepslope on the A410vs. time (seconds) plot. These resultswere interpreted as:
| a) | the rapid release of the first product(p-nitrophenolate), followed by the slower reaction ofacetate ion (the other product) with a catalytic lysine residue onthe enzyme |
| b) | the unusual properties of aromatic esters and thus notapplicable to the normal chymotrypsin mechanism, which involves thehydrolysis of peptide bonds |
| c) | the rapid release of p-nitrophenol, followed by theslower formation of the p-nitrophenolate ion |
| d) | the rapid release of the first product(p-nitrophenolate), followed by the slower hydrolysis ofthe acyl-enzyme intermediate |
