Which of the following is not the function of cell wall?

1. Provides shape to the cell.
2. Protects the cell from mechanical damage and infection.
3. Helps in cell to cell interaction.
4. Provides barrier to undesirable macromolecules.

All the given function is related to cell wall. Cell wall is a very tough, flexible and fairly rigid layer that surrounds some types of cells. It surrounds the cell membrane and provides these cells with structural support and protection. In also acts as a filtering mechanism.