Modeling the colloidal physics of life-essential processes 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 bacterial cell, where biomolecules and their interactions are physically represented, individually and explicitly. With it, we tackle a fundamental open question in biology from a physico-chemical perspective: why does protein synthesis speed up at faster growth rates? I will report our findings in answer to this question, and demonstrate the general applicability of our "bio-colloidal" framework to other open questions in macromolecular and cellular biology, including the role of gel maturation in neurodegenerative disease inheritance.