Principles of Cellular Organization

In the third part, I discuss how the complex shapes of cells are created by the cytoskeleton, and I compare and contrast prokaryotes (which have actin-, tubulin-, and intermediate filament -like proteins) and eukaryotes in this regard. In particular, I speculate that cytoskeletal dynamics were necessary to evolve simple bacterial shapes and cell division, but that additional layers of complexity (namely regulated nucleation and molecular motors) allowed eukaryotes to evolve more complex shapes and organize their internal components.