Analysis of permeability data for the case of parallel diffusion pathways.

A method of analyzing permeability or diffusion temperature-flux data, for the case of two parallel, independent diffusion fluxes is presented. Separate activation energies and frequency factors corresponding to independent and concurrent Arrhenius mechanisms are obtained from this procedure when the fluxes are of comparable magnitude. The method is developed in terms of membrane permeability theory since spatially separate and distinct diffusion pathways are of frequent occurrence in biological membranes. It is illustrated in the specific case of water diffusion through a keratin membrane. The results implicate the presence of "bound" water as a crucial factor in passive diffusion of water and polar molecules through the membrane.