The N acetylglucosamine molecule in 3-D

The N acetylglucosamine molecule - rotatable in 3 dimensions

N-acetylglucosamine is a modified version of glucose, with an amino group , substituted with an acetyl (ethanoyl) group, attached to carbon 2.

It is the basic subunit from which the polysaccharide chitin, used in arthropod exoskeletons and in some fungal cell walls, is built up.

It is also a component of peptidoglycan (murein) which forms the cell wall of many bacteria. This consists of alternating residues of β-(1,4) linked N-acetylglucosamine and N-acetylmuramic acid, to which a short chain of amino-acids is attached, permitting cross-linking with other strands.