Suppose chymotrypsin is labeled by producing an enzyme that contains a particular residue as radioactive. Suppose 100ug of non-radioactive chymotrypsin (25.2kDa) is added to substrate produce a total of 10mL of solution with a final concentration of 1mM of non-radioactive peptide substrate. The entire buffer in both the enzyme preparation and the substrate preparation is in 3H218O. The Km for this substrate and chymotrypsin in these conditions is 0.2uM.You measure the initial velocity of the reaction and obtain 75umol of 18O peptide per minute per 10mL. What is the Kcat for this enzyme in s-1? Which product, 1st or 2nd is being measured? Will this product release have a burst phase?