Sweetzyme Q is a commercial preparation of immobilized glucose isomerase manufactured by Novo Industries of Denmark. The following data were obtained for immobilized enzyme particles of different sizes:
|
Diameter
|
50 pm
|
100 um
|
190 pm
|
300 um
|
650 um
|
|
Vcbs
μxylose isomerized/(min)(μL support)
|
0.285
|
0.285
|
0.220
|
0.19
|
0.17
|
|
S2 (M)
|
1.5
|
1.5
|
1.5
|
1.5
|
1.5
|
a) When considering mass transfer in this porous sphere scenario, there are several regions to consider. Draw and label these for a spherical particle.
b) Assume that Da <<0.1 and β≈0. What is the internal effectiveness factor for the largest catalyst particle?
c) Estimate the effective diffusivity of the substrate through the catalyst pores of the largest particle.