Bacterial cell wall

bacterial wall-Main functions include keeping cell shape (like an

exoskeleton).

Prevents cell lysis. (can withstand internal

high as water osmotic]pressure. pressosmotic floods in the

· Pressure builds.

:- the cell wall acts

-

:.......as a dam to keep

water in

.

Most bacterial cell walls comprised of peptidoglycan /made of sugar+ amino acids.

- glycan part alternates+ repeats sugars

peptido--amino acids form peptide bond cross links·

N-acetyl giucosomine (NAG)

·

connect the Chains of Sugars (NAG, NAM·

N-acetylmuranic acid (NAM)

Gramtvs . Gram-

Gram positive cells have a thick layer of peptidoglycan

· 90 % peptidoglycanand 20-80nm thick

· They have teichoic acids anchored in cell wal

Gram negative have a thin layer of peptidoglycan (onlyn 2nm)

outer membrane contains Lipopolysaccharides (LDS)* Lipid A : acts as endotoxin

Periplasm: Space between cell + outer membrane

Gram Positive+ Gram Negative Cells have different susceptibility to :

enzymes and antibiotics