Our whole body is built on innumerable cells and these are the units which are the basis of our existence. Different types of functions are carried out in our body with the help of these cells. The cells are of two types: Prokaryotes and eukaryotes. These cells are divided into three parts: cell membrane, nucleus and cytoplasm. Several organelles are located inside the cell membrane.
What is a cell membrane?
Cell membrane is also called as plasma membrane. It is an important part of cell and encloses as well as protects the various constituents of cells. It performs the important part of separating the internal cell matter from the outside environment. Different organelles of cell are embedded within the cell membrane along with the fluid in which these organelles are placed in suspension. In fungi, plants or even bacteria the cell membrane is surrounded by a cell wall.
What is the structure of cell membrane?
Cell membrane is composed of two phospholipid layers and the molecules of phospholipids have head called as hydrophilic as well as a tail called as hydrophobic. The arrangement of these phospholipid layers is such that head region at the exterior and the internal surface of plasma membrane and also the tail are arranged very close to the cell membrane center. This membrane also constitutes various protein molecules which lay embedded in the phospholipid layer. The function of cell membrane is carried out by all these components together.
What are the functions of cell membrane?
The main or primary function of cell membrane is to serve as the protective cover for You do not have access to view this node. It also performs various other functions apart from this.
It secures the cytoskeleton that is made up of protein and located in cytoplasm and also gives shape to the overall cell structure
It serves the function of attaching cell to extracellular matrix which is a non living external material for enabling the group formation of cells. These grouped cells then form You do not have access to view this node.
The transportation of materials which are essential for the cell organelles functioning is one of the vital functions of cell membrane. Since the cell membrane is semi permeable it controls the out and in movement of various components. This movement is carried out by using cellular energy or passively without using cellular energy.
The protein molecules present in the plasma membrane accept signals from other cells or even from the external environment. These signals are converted into messages which are then forwarded to the cell organelles.
Sometimes the protein molecules in the plasma membrane come together and form enzymes to perform metabolic reactions and especially near internal cell membrane surface.
What are the main proteins involved in cell membrane?
Four main types of proteins are related to cell membrane.
Integral proteins – These are placed in the membrane in such a way that they come in contact with both the internal as well as the external environ of the You do not have access to view this node.
Transmembrane channel proteins – These are almost similar to the above proteins but performs the function of connecting cytoplasm to the extra cellular fluid.
Surface membrane proteins – These proteins are present only on the outer layer of membrane.