Why Cells are Microscopic: A Transport-time Perspective
S. Soh1 , M. Banaszak2 , K. Kandere-Grzybowska1 , B.A. Grzybowski1,3
1 Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Rd, Illinois 60208, USA.
2 Faculty of Physics, Adam Mickiewicz University, Ul. Umultowska 85 61-614 Poznan, Poland
3 Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Illinois 60208, USA
The Journal of Physical Chemistry Letters, 4, 861–865 (2013)
Physical-chemical reasoning is used to demonstrate that the sizes of both prokaryotic and eukaryotic cells are such that they minimize the times needed for the macromolecules to migrate throughout the cells and interact/react with one another. This conclusion does not depend on a particular form of the crowded-medium diffusion model, as thus points toward a potential optimization principle of cellular organisms. In eukaryotes, size optimality renders the diffusive transport as efficient as active transport – in this way, the cells can conserve energetic resources that would otherwise be expended in active transport.