peptidoglycan biosynthesis GO:0009252 PMID:SBN:0-13-144329-1 UPa:UPA00219 murein biosynthesis Biosynthesis of peptidoglycan, also known as murein, a polymer consisting of sugars and amino-acids that forms a mesh-like layer outside the plasma membrane of eubacteria. The sugar component consists of alternating residues of beta-(1,4) linked N-acetylglucosamine and N-acetylmuramic acid residues. Attached to the N-acetylmuramic acid is a peptide chain of three to five amino-acids. The peptide chain can be cross-linked to the peptide chain of another strand forming the 3D mesh-like layer. Some Archaea have a similar layer of pseudopeptidoglycan. Peptidoglycan serves a structural role in the bacterial cell wall, giving structural strength, as well as counteracting the osmotic pressure of the cytoplasm. Peptidoglycan is also involved in binary fission during bacterial cell reproduction.[wikipedia]. pathway cell wall biogenesis