The plant cells have an additional protective wall outside the plasma membrane, celled a cell wall. It is a relatively thick, nonliving and rigid envelop. It is impermeable and is made up of cellulose (a kind of carbohydrate). It may be a thin or thick, multilayered structure as in bacteria.


1. It determines the shape of the plant cell.

2. It prevents desiccation (drying up) of cells.

3. It protects the plasma membrane and internal structure of the cell.


4. It helps in the transport of various substances in and out of the cell.

5. It does not allow too much of water to come in. in this way it prevents the cytoplasm from becoming too dilute.