» Not to be confused with glycoprotein. Peptidoglycan, also known as murein,'s a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria, forming the cell wall. The sugar component consists of alternating residues of β-(1,4) linked N-acetylglucosamine and N-acetylmuramic acid residues. Attached to the N-acetylmuramic acid's a peptide chain of three to five amino acids. The peptide chain can be cross-linked to the peptide chain of an… (More on Peptidoglycan)