C. Nigon et al., THEORETICAL-ANALYSIS OF ACTIVE-TRANSPORT THROUGH A REVERSED BIENZYME POROUS MEMBRANE - II - TRANSPORT OF AN UNCHARGED, SMALL, HYDROPHILIC MOLECULE, Journal of membrane science, 144(1-2), 1998, pp. 237-250
Theoretical analysis of the active transport of an uncharged solute th
rough a reversed bienzyme porous membrane separating two compartments
is presented. The main parameters taken into account in the correspond
ing model were analyzed in terms of their impact, both on the final su
bstrate surconcentration (SR) ratio and on the final product pollution
level expected in the receiving compartment of a diffusion cell. Comp
ared to our earlier analysis dealing with the transport of a negativel
y charged solute, this analysis conoborates that an active transport m
ay occur only if three key factors act together and simultaneously: (i
) bound reversed enzyme activities must exist at the pore entrance/exi
t; (ii) the first enzyme of the reactional sequence involved acts in a
n unstirred layer facing the feed compartment; (iii) to perform active
transport of an uncharged substrate, the negatively charged intermedi
ary product must be attracted by the positive charges within the membr
ane's pores. Once again, it was found that the unstirred layer facing
the feed chamber governs the substrate SR expected in the opposite rec
eiving chamber, while the unstirred layer facing the receiving chamber
plays a role only on this transport rate. A global synthesis, underli
ning the different possibilities of such ''intelligent'' membranes, is
also presented. (C) 1998 Elsevier Science B.V.