Diffusion in biolgical cells

Diffusion in biolgical cells

Ralf Metzler

Modern experimental techniques allow us to observe single proteins being produced in a living biological cell, one protein at a time. Such proteins then diffuse through the cell, to effect followup reactions, such as the control of specific genes to which the protein can bind. The first part of this seminar will explore the physics of the regulation of genes by diffusing proteins. Starting from simple models increasing complexity will be included, demonstrating that even a micron-sized bacteria cell is not a well mixed chemical reaction container but the full diffusional path of the proteins needs to be considered.

In the second part of the talk I will address how experimentalists explore the mechanical properties of biological cells by means of microscopical tracking of micron sized particles. Such microrheology experiments show that the observed diffusion law is not that of normal Brownian motion.
I will discuss some of the experiments and how physical models can help to analyse the details of the particle diffusion.