A rigid structure but with pores and channels allowing substances to move across easily

A dynamic structure in which there is a lot of lateral movement of the phospholipids of the bilayer as well as, more rarely, flip-flop motion

A generally rigid structure but one in which at least the phospholipids can routinely undergo flip-flop but not lateral motion

A generally rigid structure but one in which at least the integral proteins can routinely undergo flip-flop but not lateral motion

A rigid structure that gives the cell identity from its environment