Learning Outcomes:

After this lesson, you should be able to:

• Describe the functions and general structure of the plasma membrane.

Surrounding each cell is a “fence” called a plasma membrane. This membrane serves several important functions, including structural support, communication with other cells, regulation of transport into and out of the cell, and cell identification. It functions as a boundary separating the substances inside the cell, which are IntraCellular (ICF), or fluid (cytosol) space, from the substances outside the cell, which are ExtraCellular (ECF).



The plasma membrane encloses and supports the cell contents, as well as determines what enters and exits a cell.

An electrical charge difference across the plasma membrane called the membrane potential is a result of the cell’s regulation of ion movement into and out of the cell.