Simulation of biomembranes and model membrane systems over length and time scales relevant to cellular biology is not currently feasible with Molecular Dynamics or related atomically-detailed methods. Barring an unforeseen revolution in the computer industry, this situation will not change for several decades. Two aspects of membrane dynamics will be discussed: out-of-plane membrane undulations and in-plane flow/diffusion in inhomogeneous membrane systems. Both problems are treated within the context of continuum models, which allow access to length and time scales up to and beyond the micron and second regimes, using simple numerical methods. A number of effects relevant to the motion of integral membrane proteins as well as the dynamics of phase separation and domain fluctuations in multi-component lipid bilayers will be presented.
