A cell is a basic unit of life; we classify cells into two categories; Plant cells and Animal cells. These cells are differentiated from each other on several bases, out of which one of the most prominent base is the covering of the cell. There are two covering found around cells; one is cell wall while other is the cell membrane. The cell wall is a feature of plant cells; it is only found in plants cell, not in animal cells. Plants cell also have a cell membrane, but cell wall externally covers this cell membrane. The cell membrane is found both in plant cells and animal cells, but it is predominantly seen in animal cells.
What is Cell Wall?
The outermost covering of plant cells is known as the cell wall. It is a characteristic feature of only plant and bacterial cells; it is absent in animal cells. The cell wall is the only non-living structure found in plant cells. The thickness of cell wall varies from 4-20uM. Its function is to protect the cell and its organelles from the external environment. The cell wall is more rigid than other covering, due to this it has a great protective function and provides a fixed shape to the cell. It also provides stability to plant cells. The cell wall is metabolic inactive, and it contains cellulose. The cell wall is made up of pectin, chitin, lignin, etc. Cell wall lacks receptors, and it is totally permeable. With the passage of time, cell wall increases in thickness and strength. Its only function is to provide stability and protect the cell from external hazards.
What is Cell Membrane?
The cell membrane is the outermost covering of animal cells. It is found in animal cells as well as in plants cells. The cell membrane is a living structure of the cells. Its thickness is 5-10nm wide. It is made up of lipids, proteins, and carbohydrates. It protects the protoplasm from the external environment and maintains the internal matter of the cell. The cell membrane is metabolic active and does not contain cellulose in it. The cell membrane is semi-permeable as it allows some structure or molecules to pass through it. Moreover, cell membrane contains receptor of different kinds. The cell membrane is elastic; it provides flexibility to the cell, and it maintains the cytoplasm and osmotic balance inside the cell. Cell membrane also requires food and nutrition from the cell as it is living organelle of the cell.
Cell Wall vs. Cell Membrane
- The cell wall is found in the plants, bacterial cells. It is not present in animal cells while cell membrane is present in all types of cells.
- The cell wall is the outermost covering of plant cells, whereas cell membrane is an outermost covering of animal cells.
- The cell wall is non-living and metabolic inactive, whereas, the cell membrane is living and metabolic active.
- The cell wall is more rigid and thicker than cell membrane.
- The cell wall is totally permeable, whereas cell membrane is semi-permeable.
- Cell wall contains cellulose in it and contrary to this cell membrane lacks cellulose.