Both bacteria and fungi have cell walls, but their compositions are different. The cell wall of bacteria is composed of peptidoglycan, also known as mucin. The mechanical strength of cell wall depends on the existence of peptidoglycan. The main component of fungal cell wall is polysaccharide, followed by protein and lipids. In different groups of fungi, the types of cell wall polysaccharides are different. Fungal cell wall polysaccharides mainly include chitin, cellulose, dextran and mannan. These polysaccharides are polymers of monosaccharides.