All of the following are true of the plasma membrane, except

A) it is mainly composed of a phospholipid bilayer.
B) it is selectively permeable to various substances, controlling which substances can cross the membrane.
C) the glycocalyx provides structural integrity to the plasma membrane.
D) transmembrane proteins may function as ion channels, enzymes, or receptors.
E) charged or large molecules can sometimes enter a cell via membrane proteins.

Glycocalyx

A dense layer of glycoproteins and polysaccharides that surrounds the plasma membrane of cells, important for cell recognition and interaction.

Phospholipid Bilayer

A fundamental structure in all cell membranes, consisting of two layers of phospholipids, which provides a barrier that marks the boundaries of a cell.

Selectively Permeable

A property of cell membranes that allows certain molecules or ions to pass through it by means of active or passive transport, while blocking others.