The cohesion of membranes is maintained through hydrophobic interactions.
Within a single layer, proteins and lipids can move laterally, but they infrequently transition to the opposite layer.
Some of these molecules navigate along cytoskeletal fibers.
Membranes retain their fluid nature even as temperatures drop until the phospholipids organize into a tightly packed structure.
Higher amounts of phospholipids with unsaturated hydrocarbon tails contribute to prolonged fluidity of the membrane.
This is due to the bends in the tails creating more separation.
Cholesterol
At elevated temperatures, the presence of cholesterol decreases the fluidity of the membrane.
It restricts the movement of phospholipids.
Cholesterol also reduces the temperature at which membranes solidify since they are less densely packed.
It acts as a temperature stabilizer.
