A) They frequently flip- flop from one side of the membrane to the other.
B) They form a viscous fluid through which proteins shift and flow.
C) They have hydrophilic tails in the interior of the membrane.
D) They occur in an uninterrupted bilayer, with membrane proteins strictly anchored to the surface of the membrane.
E) They are free to depart from the membrane and are dissolved in the surrounding solution.

A) external proteins.
B) carbohydrates.
C) lipids.
D) nucleic acids.
E) internal proteins.

A) many proteins can move around within the bilayer.
B) proteins are asymmetrically distributed within the membrane.
C) all proteins are anchored within the membrane.
D) different membranes contain different proteins.
E) all proteins in the plasma membrane come from a membrane other than the human or the mouse.