Biophysics and Soft Matter Seminar

A Different Frontier of Theoretical Physics – Complex Systems, Emergence, and Chemistry

Mon, 15 Jan 2018 1:30 PM
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Biophysics and Soft Matter Seminar
A Different Frontier of Theoretical Physics – Complex Systems, Emergence, and Chemistry

Hong Qian
University of Washington, Dept of Applied Math

Jan 15, 2018 at 1:30pm in P8445.2

Synopsis

While high energy physics discovers more and more fundamental particles, it leaves behind an ever growing complex world that requires a different mathematical representation: This is the essence of Chemistry as pointed out by Carl Anderson.  In contrast to featureless point masses in Mechanics, a molecule in Chemistry has a large number of internal degrees of freedom in terms of atoms, electrons, etc.  The behavior of even a single biomolecule, a protein in an aqueous environment, is often so complex that the mathematical representation of biochemical kinetics has to be statistical.  In this talk, I present a classical, stochastic description of general chemical reaction systems in solution and show how J. W. Gibbs’ macroscopic equilibrium chemical thermodynamics can be derived as a mathematical result, with an entropic force as its center piece. Our theory is actually applicable to mesoscopic open chemical systems such as a single living cell.  I then discuss the application of this theory to understand the notion of non-genetic phenotype switching, in terms of a landscape, in cell differentiation and cancer heterogeneity.