  We discuss a theoretical model for bidirectional cargo transport in
biological cells, which is driven by teams of molecular motors and subject to
thermal fluctuations. The model describes explicitly the directed motion of the
molecular motors on the filament. The motor-cargo coupling is implemented via
linear springs. By means of extensive Monte Carlo simulations we show that the
model describes the experimentally observed regimes of anomalous diffusion,
i.e. subdiffusive behavior at short times followed by superdiffusion at
intermediate times. The model results indicate that subdiffuse regime is
induced by thermal fluctuations while the superdiffusive motion is generated by
correlations of the motors' activity. We also tested the efficiency of
bidirectional cargo transport in crowded areas by measuring its ability to pass
barriers with increased viscosity. Our results show a remarkable gain of
efficiency for high viscosities.
