JEE Advanced levelNumerical answerDifficulty 3 of 3sc099
Carbonic anhydrase (M=30000gmol−1) has a turnover number kcat=6.0×105s−1 (substrate molecules per enzyme per second at saturation). Assuming saturation throughout, what mass of COX2 (M=44gmol−1) is hydrated by 1.7mg of the enzyme in 1.0min? Answer in grams to one decimal.
Numerical answer type, answer in g, tolerance 0.1.
Answer: 89.8 g
Moles of enzyme =1.7×10−3/30000=5.667e−08mol. Rate =6.0×105×5.667e−08=0.0340mols−1. In 60 s this is 2.040 mol, a mass of ×44=89.76 g, i.e. 89.8 g.