Prokaryotes, such as bacteria, also have a cell wall. Its functions are similar to that of the plant cell, (protects it, maintains shape, gives support) however prokaryotic cell walls are not made of cellulose, like plant cells. The prokaryotic cell wall is made of peptidoglycan, which is a combination of disaccharides and peptide fragments. All prokaryotes have peptidoglycan in their cell walls.