12.8 Effect of temperature on the hydrolysis of starch a-Amylase from malt is used to hydrolyse starch. The dependence of the initial reaction rate on temperature is determined experimentally. Results measured at fixed starch and enzyme concentrations are listed in the following table. Rate of Glucose Production (mmol m Temperature (C) s-1) 20 30 0.31 0.66 1.20 6.33 40 60 (a) Determine the activation energy for this reaction. (b) a-Amylase is used to break down starch in baby food. It is proposed to conduct the reaction at a relatively high temperature so that the viscosity is reduced. What is the reaction rate at 55C compared with 25C? (c) Thermal deactivation of this enzyme is described by the equation: ka = 2.25 X 1027 -41,630/RT 4. REACTIONS AND REACTORS 692 12. HOMOGENEOUS REACTIONS where ka is the deactivation rate constant in h?, R is the ideal gas constant in cal gmol K-1, and T is temperature in K. What is the half-life of the enzyme at 55C compared with 25C? Which of these two operating temperatures is more practical for processing baby food? Explain your