The flux of oxygen within tissues.

Diffusive flux of oxygen through tissues which are essentially connective and have few cells, display reduced diffusion coefficients when compared to that through an equivalent lamina of water. In general even significant reductions can be explained in terms of the exclusions imposed on small molecular weight diffusates by the large hydrodynamic domains of the connective tissue components. An alternative way of explaining this large exclusion is to point to the very large microscopic viscosities which large interacting polymers impose upon the solvent (water).

How proton translocation across mitochondrial inner membranes drives the Fo rotor of ATP synthase.

It has been believed for some time that there are two major but alternative models for the selective transport of ions across membranes generally. On the one hand this transport is by way of transmembrane channels. These channels exist within macromolecular complexes which span the membrane and provide a hydrophilic pathway through which the ions can be translocated.