Berlin 2012 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 2: Physics of Cells I

BP 2.5: Vortrag

Montag, 26. März 2012, 10:45–11:00, H 1028

Cytoplasmic streaming in giant algae cells: the role of wall slip — •Katrin Wolff, Davide Marenduzzo, and Mike Cates — SUPA, School of Physics & Astronomy, University of Edinburgh, UK

We present lattice Boltzmann simulations of a microscopic model for cytoplasmic streaming in algal cells such as those of Chara corallina. The fluid motion is driven by myosin motors carrying vesicles or other organelles and moving along actin filaments which are attached to the outer part of the cytoplasm. We address how the high speeds observed in experiments can be achieved by assuming a layer of lower viscosity at the outer wall of the simulated compartment. To this end we introduce a finite slip boundary condition at the wall close to which the motors move. The motivation behind the low-viscosity layer is the assumption that those cell contents populating the cytoplasm do not reach up to the cell wall resulting in a more dilute solution close to the wall. We find that this simplified view, which does not rely on any coupling between motors, cytoplasm and vacuole other than that provided by viscous Stokes flow, accounts very well for the observed magnitude of streaming velocities [1].

[1] K. Wolff, D. Marenduzzo, M. Cates, Cytoplasmic streaming in giant algae cells: the role of wall slip (submitted)