A specialized layer surrounds each cell of plants, prokaryotes such as algae, bacteria, and certain eukaryotes such as fungi.
Functions performed by cell walls include providing mechanical protection to cells, providing a chemical environment for the circulation of water, nutrients, and minerals, and providing building blocks from rigid stable structures such as leaves and stems of a plant are produced.
Example of a cell wall: The cell wall of plants is a classic example.
The plant's cells are enclosed by a tough, extensible primary cell wall which is composed of pectin, cellulose, and hemicellulose.
The other thick and strong layer deposits beneath the primary layer of the cell wall is referred to as the secondary cell wall, rich in phenolic compound (lignin)
The two primary cell walls are interconnected through a pectin-rich intercellular material that glues two adjacent cells together.