The hard non-living covering found outside the protoplasmic membrane of plants is called cell wall. The bacterial cell wall is made up of proteins, lipids and polysaccharides. Apart from this, N-acetyl glucosamine acid and N-acetyl muramic acid are found in the cell wall. The cell wall protects the cell from mechanical damage and infection, as well as maintains interactions between cells and provides a barrier to undesirable macromolecules. The cell wall in fungi is made up of chitin or fungal cellulose. The cell wall of algae is made up of cellulose, galactans and minerals like calcium carbonate. In other plants it is made up of cellulose, hemicellulose, pectin and lignin. The cell wall is a wall-like layer that surrounds the protoplasm. It encloses the protoplasm and acts as a safety cover. Structure Now that we have known what is a cell wall, let us have a look about its structure. On the basis of structure the following types of cell wall are found. 1. Primary wal...