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.