Difference between Cell Wall and Cell Membrane
One of the fundamental difference between the plasma membrane and the cell wall is in the type of organisms that they are found. The cell wall is present only in plants and the cell membrane is present in every living organism including plants.
CELL WALL | CELL MEMBRANE |
Present only in plants, and in some fungi, bacteria, algae. | Present in all types of cells, in humans, animals, plants, bacteria, etc. |
It is the outer non-living part of the cell but not an organelle which encloses cell membrane and provides a fixed shape. | It is an outermost, flexible, living organelle of the cell which provides shape to the cell. |
It is made up of pectin, chitin, lignin, glycol proteins, glycolipids, sugar, and cellulose. | It is a lipid bi layer. And is composed of lipo-proteins and carbohydrates. |
The structure of the cell wall is 20- 80nm in thickness | The structure of the cell membrane is 7.5–10 nm in thickness |
It is the thick and rigid structure with a fixed shape. | It is thin and delicate structure. It is flexible to change the shape as needed. |
It protects the cell from the external environment. | It protects and maintains the internal environment of the cell. |
The cell wall is elastic. | The cell membrane is non-elastic. |
The cell wall is metabolically inactive | The cell membrane is metabolically active. |
Cell wall lack receptors. | The cell membrane has receptors to receive signals from external chemicals. |
The cell wall grows in thickness over time. Further, it occupies the whole cell in the plant as the cell ages and dies. | It is of the same thickness for the whole lifetime of the organism. |
The cell wall is semi-permeable. It allows passage of substances with the size of 30-60 kD. | The membrane is permeable and controls the movement of the substance into and outside the cell. That is, it can allow water and other substance to pass through selectively. |
Functions include protection from the external environment. | Functions include permeability, signal reception, motility conduction, cell division, sexual reproduction etc. |
Conclusion
The cell wall and cell membrane are two organelles that are integral in every living organism. However, the latter is found only in plants, fungi and in some bacteria. Traditionally, a cell well is defined as the layer of polysaccharides that exists outside the plasma membrane. It is rigid and serves structural and supportive functions. On the other hand, the cell wall in fungi is made from another material called chitin, which is also found in the exoskeletons of arthropods.
The cell membrane is present in all living organisms, including plants. It is the outermost layer of the cell and encloses other cellular organelles within in. Unlike the cell wall, the cell membrane is flexible and its shape can be changed as needed. Also, it is metabolically active and has increased membrane permeability.