Functions of the Plasma Membrane

Functions of the Plasma Membrane

Apart from holding the contents of a cell, the plasma membrane serves various important functions in cell regulation. This Buzzle article explains what a plasma membrane is along with its functions.
Cells are the most basic entities that are responsible for life on this Earth. There have been numerous researches about the structure and functioning of cells, and scientists are still trying to unravel the mysteries of these life-sustaining cells. On an average, there are nearly trillions of cells in the body and all work together for the proper functioning of the body.

What is a Plasma Membrane?

It a biological membrane of the cell that forms the external covering of both types of cells, the prokaryotic and eukaryotic. It acts as an outer boundary, preventing the cell from the invasion of external germs. The plasma consists of various biological molecules, lipids, and proteins that help in the regulation of body functions. There have been various theories concerning their structure that have been given by various scientists after years of research. The Fluid Mosaic Model and lipid bilayer are two theories that give explanations regarding their formation.


In order to understand the functioning of these membranes in cells, we've to understand basic functions of phospholipids, that are an integral part of this membrane. Phospholipids are the lipids that have two opposite functioning parts. While one end of the phospholipid is hydrophilic (water-loving), the other end is hydrophobic (water-repelling). These two ends help in proper functioning of the cells when they are mixed with water molecules. In the phospholipid bilayer, there are various proteins like peripheral, maker, transport, and receptor proteins that are the most important workers of the cell. With the help of these proteins, the cell membrane transfers the required materials in and out of the cell.

Its another function is to act as an attachment to the non-living matter that is found outside the cell membrane. This matter, known as extracellular matrix, helps in grouping the cells so that they can form tissues. Enzymes are another important part of cells, and protein molecules in the cells combine together to form enzymes that are involved in carrying out metabolic processes near the surface of the plasma membrane.

It also helps in the transportation of materials, that is crucial for the proper functioning of various cell organelles. This semipermeable membrane of the cells helps in the transferring those nutrients and chemicals that are required for the functioning of the cell. The other foreign materials are obstructed on their path, thereby preventing the invasion of the membrane.

It maintains a suitable 'cell potential'. Just like electric signals can be transferred by creating some potential difference between two points, the cell maintains a cell potential that helps in the exchange of signals with the parts outside the cell. There are certain proteins in this membrane that act as molecular signals for this communication process. It contains carbohydrates, and the materials that pass through them are carefully regulated by these cellular molecules. While important requirements like carbon dioxide, oxygen, and water are allowed to be exchanged, the passage of molecules like amino acids and sugar is maintained effectively by these membranes.

As we can see, every function is significant in its own way and helps in the regulation of the health and maintenance of the body. These were some of the functions that help us in our body functions.