Emergence of collective spatio-temporal patterns in autocatalytic reactions

by Francesca Di Patti (Dipartimento di Fisica, Università di Padova)

Monday 26 Apr 2010, 15:00 → 18:00 Europe/Rome

Aula Conversi (Dipartimento di Fisica - Ed. G.Marconi)

We present a simplified model of the coupled autocatalytic reactions occurring inside vesicles, small cell-like structures in which the outer membrane is formed by a lipid bilayer. The role of stochastic fluctuations is elucidated via a van Kampen expansion and results are compared with stochastic simulations. Regular temporal oscillations of concentrations are predicted to occur, with enhanced amplitude resulting from a resonance induced by the intrinsic graininess of the system. We then introduce a spatial coarse graining at the level of microc! ells that uniformly cover the volume occupied by the vesicle. Autocatalytic reactions occur in each microcell and migration between neighbor cells is allowed. We first study a periodic geometry by focusing on a chain of microcells located at the frontier with the external membrane. Finally we explore the possibility to simulate a more realistic scenario, namely a three dimensional vesicle.