Cholesterol and various proteins are also embedded within the membrane giving the membrane a variety of functions described below.Ī single phospholipid molecule has a phosphate group on one end, called the “head,” and two side-by-side chains of fatty acids that make up the lipid “tails” ( Figure 3.1.1). The cell membrane is an extremely pliable structure composed primarily of two layers of phospholipids (a “bilayer”). Structure and Composition of the Cell Membrane This cell membrane provides a protective barrier around the cell and regulates which materials can pass in or out. Just as the outer layer of your skin separates your body from its environment, the cell membrane (also known as the plasma membrane) separates the inner contents of a cell from its exterior environment.
Relate structures of the cell membrane to its functions.Describe the molecular components that make up the cell membrane.By the end of this section, you will be able to:
