“Cellular Stokesian Dynamics”: The Colloidal Hydrodynamics of Biological Cells

The frontier in operational mastery of biological cells arguably resides at the interface between biology and colloid physics: cellular processes that operate over colloidal length scales, where continuum fluid mechanics and Brownian motion underlie whole-cell scale behavior. It is at this scale that much of cell machinery operates and is where reconstitution and manipulation of cells is most challenging. This operational regime is centered between the two well-studied limits of structural and systems biology: the former focuses on atomistic-scale spatial resolution with little time evolution, and the latter on kinetic models that abstract space away. Colloidal hydrodynamics modeling bridges this divide by unifying the disparate length and time-scales of solvent-molecule and colloidal dynamics, and may hold a key to numerous open questions in biological cell function. I will discuss our physics-based computational model of a biological cell, where biomolecules and their interactions are physically represented, individually and explicitly. With it, we study a model process: translation elongation. We find that Brownian self-diffusion is critical to life-essential processes and may play a regulatory role, along with other colloidal forces.