The cell membrane is a thin living plasma membrane that surrounds the cytoplasm from the outside, its thickness ranges from 7-8 nanometers, and it is in the form of a semi-permeable capable of separating the contents of the cell from the medium in which it is located.
Where the cell membrane consists of two layers of phosphorylated lipids, as well as integrative proteins that are immersed in the membrane, in addition to terminal proteins, where the distribution of proteins is irregular, and in this article we will talk about the functions of the cell membrane.
Components of the cell membrane
The components of the cell membrane are characterized by the ability to move from one place to another; The reason for this is that the phosphorylated lipid molecules have the ability to switch places with each other, in addition to the protein molecules possessing the same property.
And this explains why this membrane is called a dynamic membrane, and the phospholipids have a charged polar head so that it attracts with the poles of the water molecule, and this explains why it is loving Water, as well as a non-polar and non-charged tail so that it attracts water, and therefore it is not hydrophilic.
What are the characteristics of the cell membrane?
The cell membrane is distinguished by its possession of a set of vital properties that help it perform various functions that are compatible with its structure, as it grows with the growth of the cell, and it is able to renew itself in the areas where it has been subjected to rupture.
What are the functions of the cell membrane?
What distinguishes the cell membrane most is its ability to give the cell a distinctive shape, thus preserving its contents.
It regulates the exchange of different molecules and ions from the cell itself and even the medium in which it lives.
The cell membrane contains some structures that have many functions, and the most important of these structures are:
Cilia are defined as short appendages from which each basal body originates inside the cell, and their main function is the ability to move the cell using the paddle harmonic movement, and it is present in some organisms; Ex: Paramecium.
Flagella are similar to cilia in terms of function and structures, but they are characterized by being longer and fewer in number in the cell. It is indicated that they move in a fan, and they are present in some organisms; Ex: Euglena.
The cell wall is a thin and flexible cell wall that surrounds the cell membrane of the cell, and it consists of a group of pectic materials, as well as cellulose, which is found in new cells, as the thickness of the cell membrane increases.
The reason for this is due to the deposition of layers of other materials; Such as: lignin, chitin, It is noteworthy that plant cells communicate with each other through cytoplasmic threads that pass through holes in the cell wall.
Among the functions of the cell wall in plant cells are the following:
- It protects the cell from external dangers such as viruses, and it forms a barrier to prevent water from leaking out of the cell.
- Supports the cell and controls the direction of its growth.
- It helps the cell to withstand the pressure of filling, which may sometimes cause the cell to rupture.
- It regulates cell growth by sending signals to the cell to begin dividing.
- It regulates the passage of materials to and from the cell through selective permeability, allowing the entry of materials needed by the cell, such as proteins, and preventing the passage of other materials.
- It transmits information and secures communication between cells.
- It stores substances needed for cell growth, such as carbohydrates.