The importance of being cigar-shaped

In [1, 6, 7] we studied whether metabolic pathways with membrane-bound enzymes can give rise to significant concentration gradients in the cytosolic pathway components. We investigated this issue using a theoretical model for the phosphoenolpyruvate:glucose phosphotransferase system in E. coli, for which accurate measurements of the kinetic parameters are available. In this study we modeled an E. coli by a sphere. In reality E. coli is rod-like or rather cigar-shaped. In this paper we discuss the implementational aspects and the potential implications of a more realistic geometry.