World Bank assisted National Agricultural Research Project (NARP) - University of Port Harcourt
Abstract
The kinetics of oxidation of D-glucose catalysed by the enzyme glucose
oxidase has been studied over a wide range of experimental conditions.
The reaction velocities increased with increase in the concentrations
of the glucose oxidase and glucose, as well as increase in temperature
and ionic strength of the solution. The reaction velocity initially
increased with increase in pH, reaching a maximum at pH 6.5 and then
decreased with further increase in pH. The reaction exhibited
saturation kinetics and experimental data were analysed using the
Michaelis- Menten equation. Arrhenius activation energy and
thermodynamic activation parameters were measured and are reported. The
large negative value of entropy of activation \u394S 60 ,
-148.8JK-1mol-1, and positive value of the enthalpy of activation
\u394H 60 , 26.3kJmol-1, give further support to the proposed
mechanism. The results are interpreted in terms of a mechanism
involving both an oxidative half reaction and a reductive half
reaction