Xylose isomerase extracted from the thermophile Thermoanaerobacterium thermosulfurigenes is capable of using glucose and xylose as substrates. Applying each substrate separately, the rates of reaction are measured at 60C using an enzyme concentration of 0.06 mg ml. Initial Initial Reaction Reaction Velocity (Jumol ml min ) Glucose Velocity (umol ml min) Xylose Concentration Concentration (mM) (mM) 80 0.151 20 0.320 100 0.194 50 0.521 300 0.385 100 0.699 500 0.355 300 1.11 750 0.389 500 1.19 1000 0.433 700 1.33 1400 0.445 900 1.13 (a) What is the relative catalytic efficiency of the enzyme using xylose as substrate compared with glucose? (b) What conclusions can you draw about the substrate specificity of this enzyme?