The cell wall is a rigid, protective structure surrounding the plasma membrane in plant cells, fungi, and some bacteria. It provides mechanical strength, protection, and regulates water intake.
Composition of the Plant Cell Wall
The primary cell wall is made of cellulose, providing flexibility and strength.
The secondary cell wall (in mature cells) contains lignin, making it more rigid.
The middle lamella is rich in pectin, helping in cell adhesion.
Functions of the Cell Wall in Plants
1. Provides Structural Support – The rigid structure maintains the shape and prevents the collapse of the plant body.
2. Protection Against Pathogens – The tough wall acts as a barrier against bacteria, fungi, and viruses.
3. Prevents Excess Water Intake – The cell wall prevents the cell from bursting due to excessive water absorption, maintaining turgor pressure.
4. Facilitates Cell-to-Cell Communication – The plasmodesmata (small pores) allow exchange of molecules and signals between adjacent cells.
5. Assists in Growth and Development – The flexibility of the primary cell wall allows expansion, facilitating plant growth.