Question

Explain the three of bacterial cell walls structures and name two bacterial species representing the cell wall characters

Answer 1

Answer

Cell wall which is found outside the cell membrane,that provides strength to the bacterial cell membrane.Both Gram positive and Gram negactive bacteria consist of a ingredient called Peptidoglycan.

Structure of Peptidoglycan

It is common in both bacterial cell walls, it is a polysacharide and it has two Glucose derivates such as

1.N-Acetylglucosamine(NAG)

2.N-Acetylmuramic acid(NAM)

Research in past decade suggest that peptidoglycan is synthesized as a cylinder with a colied substructure,cross linking of each coil makes cell wall even stronger.

Gram positive and Gram negative bacteria

Cell wall of gram positive bacteria is predominantly comprised of Peptidoglycan.The additional component found in Gram negative bacteria is Teichoic acid,that is present within the pedptidoglycan layers.The Teichoic acid is a Glucopolymer.The Teichoic acid contributes the rigidity of the cell wall and cell shape particularly in case of rod shaped organisms.Staphylococus aureus is the example for Gram positive bacteria.

The Gram negative bacteria having complex structure compared to Other bacterial cell walls.It contains Lipopolysacharide(LPS).It functions with in the outer membranes of the cell wall.It has different components which helps in Contributing net negative charge to the cell membrane,protection from chemical substance and stabilization of cell walls.Pseudomonas Aeruginosa is the example for Gram negative bacteria.

Summary

We have Gram positive and Gram negative bacteria based on arrangement of cell wall.As exception Phylum Chlamydiae appear to lack peptidoglycan.Peptioglycan is the common substance found in both Gram positive and negative bacteria.Grame negative bacteria is the complex bacterial cell wall structure due to the presence of LPS(Lipopolysacharide).