Peptidoglycans,Mucopeptides, Glycopeptides, Mureins

Bacterial Microorganisms Structure
Part 2
Sizes of Disease Causing Bacteria
Shapes of Bacteria
Capsules
Gram Negative Bacterial Cell Envelope
Inner Cytoplasmic Membrane
Outer Membrane - Cell Wall
Matrix Protein
Protein 2
Band 3 Protein
Lipoprotein
Lipopolysaccharides - LPS
Lipid A
Polysaccharide
Synthesis of Lipopolysacharides
Functions of Outer Membrane
Peptidoglycans (Mucopeptides, Glycopeptides, Mureins)
Gram Positive Bacterial Cell Envelope

Peptidoglycans,Mucopeptides,Glycopeptides,Mureins

Peptidoglycans,Mucopeptides,Glycopeptides,Mureins

- Peptidoglycans (mucopeptides, glycopeptides, mureins) are the structural elements of all most all bacterial cell walls.

Halobacterium and Halococcus are the only prokaryotes known which do not have peptidoglycan in their cell walls.

This is because these organisms live in environments of high salt concentrations, and their cell contents are isosmotic with the environment.

A strong cell wall is therefore unnecessary.

The cell walls of gram negative bacteria have a comparatively, low peptidoglycan content (5-10% of the weight of the wall).

There is a low degree of cross linkage between the glycan strands of peptidoglycan.

In many gram negative bacteria the peptidoglycan layer is a monolayer, or, at the most, a bilayer.

In E. coli, peptidoglycan consists of linear polysaccharide chains consisting of alternating residues of the amino sugars N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM) linked by β-1-4-glycosidic bonds.

Free tetrapeptide side chains are attached to the NAM residues.

Some adjacent NAM residues are directly cross-linked by tetrapeptide side chains.

Home | Site map | Submit Article | Resources | Search