1

2

Human carboxylesterase 2(HC2) is expressed in the gastrointestinal tract where it hydrolyses ester-containing molecules. Below are Michaelis-Menten and Lineweaver-Burk plots showing the kinetics of HC2 activity in the presence of increasing concentrations of a natural flavonoid. Based on these plots what effect does this flavonoid have on HC2 activity? Competitive inhibition Mixed inhibition No effect Uncompetitive inhibition Below are the Km,Vmax,kcat, and kcat/Km values showing the effect of pH on the dephosphorylation of 4-MUP by alkaline phosphatase. Based on these values at what pH does alkaline phosphatase have the best substrate turnover number for this substrate? 10.0 11.0 9.5 10.5