Phospholipid movement in cell membranes What causes phospholipids to flow so quickly in cell membranes? In Biology by Cambell et al. they state that a phospholipids can travel up to 2 micrometers per second. Is that a random movement or has anyone found that phospholipids have a current?

There must be charge considerations in the movement of molecules in the lipid membrane. There is also a consideration that some species of phospholipids will migrate to portions of the membrane with sharper or smoother curvature.

Waves of electrical potential can propagate along a lipid bilayer as well, which is very important to nerve axons and extended structures like that.

In general though the membrane is held together by vanDerWaals forces like other non-polar solvents. As such, the movements of lipids and proteins and other amphipathic molecules in the membrane are still largely Brownian (random) in the 2D surface of the membrane.