KINETIC-STUDY OF THE NONENZYMATIC ISOMERI ZATION GLUCOSE-FRUCTOSE

The results obtained in the study of the nonenzimatic isomerization gl ucose-fructose are shown in this work. The equilibrium constant at dif ferent temperatures has been experimentally obtained and it has been c orrelated with values found in the bibliography and it has resulted an enthalpy change of 8.5 kJ/mol for glucose-fructose transformation. Ki netic experiments continue analyzing the concentrations of glucose and fructose by means of polarimetry and they also use an enzimatic metho d to measure the concentration of glucose. It has been deduced that th e kinetics of nonenzimatic isomerization can be adjusted to a first or der reaction in both directions and that activation energies are 109.8 and 118.3 kJ/mol. Finally, the kinetic constants have been compared w ith the ones found for enzimatic isomerization with one enzyme in homo geneous phase, reaching the conclusion that nonenzimatic isomerization may be significant in front of a catalyzed process if high temperatur es and high sustrate concentrations are used.