Mechanics of Bacterial Osmotic Shock
William Klug (UCLA)
Mechanics and Physics of Biological Cells
Mon 10:45 - 12:15
Barus-Holley 166
The mechanosensitive ion channels found in the inner membranes of bacteria are commonly thought of as the "saftey valves" that allow relaxation of sudden increases in osmotic pressure (osmotic shock). In this work we construct theoretical models to address the questions, what are the mechanisms that control tension in the membrane and what role is played by the peptidoglycan cell wall? We use the continuum theories of membrane and shell elasticity to make quantitative predictions of the cell response to shocks. We find that the anisotropy of the cell wall is a crucial mechanism for controlling the mechanical response, and that membrane rupture and the cell wall fracture are both implicated as physical mechanisms for cell death.