Dictionary > Murein


A crystal lattice structure in the cell wall of eubacteria formed by the linear chains of two alternating amino sugars (N-acetylglucosamine and N-acetylmuramic acid) that are connected to one another by the crosslinking of short peptide chains attached to N-acetylmuramic acid.
Murein serves a structural role in the cell wall of bacteria, giving structural strength and rigidity. It also serves to counteract osmotic pressure of the cytoplasm. It is involved in binary fission during bacterial cell reproduction. The Archaea have a similar layer called pseudopeptidoglycan.
The alternating sugars in the linear chain are joined by a β-(1,4)-glycosidic bond. On every N-acetylmuramic acid, a short amino acid chain (of 4 to 5 residues) is attached. Hence, cross-linking between amino acids attached to the sugar chain, particularly to N-acetylmuramic acid, a 3D structure that is strong and rigid results.
The sequence of amino acid and the molecular structure vary within species of bacteria. Murein is substantially thicker in Gram-positive bacteria than in Gram-negative bacteria.
Word origin: mur(amic acid) + –ein.

Synonym: mucopeptide, peptidoglycan.

Compare: pseudopeptidoglycan.

See also: cell wall.

You will also like...

Wart-like leaf galls on grape leaves
Plant Cell Defense

Plants protect themselves by releasing hydrogen peroxide to fight against fungal invasion. Another way is by secreting c..

Schematic diagram of DNA replication
DNA Structure & DNA Replication

DNA is a double helix structure comprised of nucleotides. A nucleotide, in turn, is made up of phosphate molecule, deoxy..

Golgi apparatus (3-D illustration)
Role of Golgi Apparatus & Endoplasmic Reticulum in Protein Synthesis

The endoplasmic reticulum and Golgi apparatus are the organelles involved in the translation step of protein synthesis a..

Cell Respiration
Cell Respiration

Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..

Physiological Homeostasis
Physiological Homeostasis

Homeostasis is essential to maintain conditions within the tolerable limits. Otherwise, the body will fail to function p..

Selective Breeding
Selective Breeding

Gregor Mendel's studies into Monohybrid and Dihybrid crossing and Charles Darwin's study of evolution and natural select..