Difference between Cell Wall and Cell Membrane

We have studied many terms in biology that has helps us in understanding various systems of our body. The reproductive system, immune system, nervous system, intestines, etc., are some of the important topics in biology. One of the interesting topics in biology is the cell wall and cell membrane. Now, what is the cell wall and cell membrane? There is a difference between these two terms, but before discussing the differences, let us first discuss the primary meaning of these terms.

Cell Wall

Cell Wall is defined as the wall present outside the cells of fungi and plants. Basically, the cell wall is the outer covering of the cells of bacteria, fungi, and plants. Plants are strengthened and supported with the help of this wall. The cell wall can prevent certain particles from entering the plant, which may damage it. The cell wall is used for protecting the plants. This wall mainly comprises of cellulose. The cell wall consists of three layers, i.e., primary cell wall, secondary cell wall, and lamella.

Cell Membrane

A cell membrane is defined as the wall that segregates the inner cells of the plants and organisms to the outer environment. This membrane is responsible for carrying out the materials inside and outside the cell. A cell membrane comprises of proteins and fatty acids. It is important to note that a cell membrane acts as a shield against the outer environment. It is also responsible for various processes like absorption of several materials, secretion, etc. The cell membrane is semi-permeable, unlike the cell wall. The cell membrane is also called the plasma membrane.

Now, let us discuss the difference between a cell wall and a cell membrane.

S.NO.CELL WALLCELL MEMBRANE
1.A cell wall is defined as the wall present in bacteria, fungi, and plants in order to protect their cells.On the other hand, the cell membrane is defined as the wall that divides and protects the inner cells of the organisms and plants against the outer environment.
2.The cell wall is only present in plants, bacteria, and fungi.The cell membrane is present in all organisms (humans and animals) and plants.
3.The cell wall comprises of seven elements. They are:
  • Cellulose
  • Glycoproteins
  • Glycolipids
  • Pectin
  • Sugar
  • Lignin
  • Chitin
On the other hand, the cell membrane is made up of four elements. They are:
  • Bilayer
  • Lipid
  • Carbohydrates
  • Lipo-proteins
4.The thickness of a cell wall varies from 0.1 micrometre to several micrometres (no limit).The thickness of the cell membrane is from 7- 10 nanometre.
5.A cell wall has a fixed shape. It is a rigid and thick wall.The cell membrane is much thinner as compared to the cell wall. The cell membrane has a delicate and structure that can be changed according to the required shape.
6.The cell wall protects the cells of the plants and fungi from the outer environment.On the other hand, a cell membrane protects the inner cells and is also responsible for maintaining its environment.
7.The cell wall is inactive, i.e., the processes take place passively.The cell membrane is active, i.e., the processes take place in an active manner.
8.The thickness of the cell wall grows after a certain period of time.Cell membrane remains of the same shape as it was before.
9.A cell wall is completely permeable.On the other hand, the cell membrane is semi-permeable. The cell membrane is responsible for carrying out the substances in and out of the body.
10.The cell wall protects the cells from the outer environment.The cell membrane has various functions: reproduction, secretion, cell division, permeability, etc.

So, these are the several differences between the cell wall and cell membrane. Well, there are certain types of cell wall and cell membrane present in plants and other organisms. So, let us discuss them briefly.

Types of Cell Wall

  1. Plant Cell Wall: Plant cell wall is defined as the cell wall present in the plants that is responsible for carrying the water in all the sections of the plant. There are two kinds of the cell wall in plants, i.e., primary membrane and secondary membrane. Primary walls in plants are very flexible, and they help the plant in growing. The secondary membrane consists of lignin that is a complex molecule responsible for making the wood of the trees. Both the membranes are responsible for carrying substances like water in various parts of the plant.
  2. Algae Cell Wall: Algae cell walls contain polysaccharides and cellulose that are present in plants as well. It also consists of the primary membrane that helps the algae in growing.
  3. Bacteria Cell Wall: Bacterial cell walls are responsible for knowing the difference between positive and negative bacteria. Peptidoglycan is a molecule found in the bacteria that forms a strong net around it so that the bacterium is not destroyed by outside forces.
  4. Fungi Cell Wall: The fungi cell walls comprises of chitin. Chitin consists of nitrogen which is responsible for stabilizing the fungi.

Types of Cell Membrane

The cell membrane is made up of three lipids. They are:

  1. Phospholipids: Phospholipids are defined as lipids that serve as a shield against the outer environment. Phospholipids are used in many food products to separate oil and water. In terms of organisms, they protect the inner cell wall from damage.
  2. Glycolipids: Glycolipids are defined as lipids containing carbohydrates. These lipids are found on the cell membrane of eukaryotic cells. These cells are responsible for maintaining the interaction between cells.
  3. Sterol: Sterol is a waxy solid substance that is found in both plants and animals. Sterols are responsible for passing the messages received from the outer environment.

So, these are some of the types of the cell wall and cell membrane. Both the cell wall and cell membrane are responsible for carrying out several processes in plants and animals. It is important to note that both are essential for all the organisms on earth. Thus, all the biological processes are carried out by both cell membrane and cell wall.






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