Energy conversion and fluctuations outside equilibrium in models of molecular motors and biofilaments

by David Lacoste (ESPCI, Paris)

Thursday 6 Oct 2011, 14:00 → 15:00 Europe/Stockholm

Nordita Seminar Room (132:028)

Molecular motors are enzymes which are able to convert the chemical energy obtained from ATP hydrolysis into mechanical work. These enzymes operate typically far from equilibrium and undergo large fluctuations. For this reason, thermodynamic quantities like work or heat are only defined in a statistical sense. These quantities obey specific constraints known as fluctuations relations. We illustrate some implications of these constraints for molecular motors. Biofilaments like microtubules and actin filaments, display unusual non-equilibrium dynamical behaviors, which are relevant for cell functioning. These behaviors, result at a microscopic scale from a coupling between the polymerization and the ATP/GTP hydrolysis. We present a model to account for this coupling in a way which is in agreement with their macroscopic dynamical behaviors.