Cyclophosphamide (CPA) is an anticancer prodrug that requires activation in the liver by cytochrome P450 2B enzymes for production of cytotoxic metabolites. Site-specific mutagenesis is used to alter the amino acid sequence of P450 2B1 in an attempt to improve the kinetics of CPA activation. The rate of reaction of CPA is studied using rat P450 2B1 and a site-specific variant of P450 2B1 produced using Escherichia coli. The results are as follows. Initial Reaction Velocity (mol min- mol P450) Initial CPA Concentration (mM) Rat P450 2B1 Variant P450 2B1 0.3 5.82 17.5 0.5 9.03 24.5 0.8 12.7 24.0 1.5 17.1 23.9 20.2 27.3 27.8 33.1 7 31.5 27.7 (a) Plot the data in the graph and determine the catalytic constants Km and Vmax. (b) Which variant has the higher binding affinity? Prove your answer (c) Which variant has the greater turnover of substrate? Prove your answer (d) Which variant is the better choice as catalytic enzyme? Prove your answer