What is difference between cell wall and cell membrane?
Definitions:
Differences:
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 made up of pectin, chitin, lignin, glycoproteins, glycolipids, sugar, and cellulose. | It is a lipid bilayer. And is composed of lipoproteins and carbohydrates. |
The cell wall is 0.1 μm to several μm in thickness. | The cell membrane is 7.5–10 nm in thickness. |
It is the thick and rigid structure with a fixed shape. | It is a 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 metabolically inactive. Thus, it is non-living in nature. | The cell membrane is metabolically active. Thus, it is living in nature. |
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 lifetime of the organism. |
The cell wall is fully permeable to smaller molecules with the size of 30-60 kDa. | The membrane is selectively permeable and controls the movement of the substance into and outside the cell. |
Functions include protection from the external environment. | Functions include permeability, signal reception, motility conduction, cell division, sexual reproduction, etc. |