Glycocalyx is a gelatinous polysaccharide and/or polypeptide covering present in the cell envelop in bacteria. When it occurs in the form of a loose sheath, it is known as a slime layer. When it occurs in the form of a thick and tough mucilage covering, it is called a capsule. Glycocalyx assists cells in adhesion to a solid surface, and also protects pathogenic bacteria from the attack of the host's immune system. It provides protection against desiccation and holds the bacterial cells together. Related Theory The animal cells and protists have an external covering over their plasma membrane which is known as a cell coat or glycocalyx and it found in bacteria. Unlike cell wall that is made up of cellulose, the cell coat is made up of a filamentous layer of oligosaccharide and glycoprotein. This layer is usually a part of the cell membrane and provides biochemical identity on the cell surface. The cell coat is strengthened and supported by the deposition of calcium salts, silicon and other materials.