major function of cell wall is to hold cell together and to prevent cell from bursting especially in aqueous solution
- all bacteria except mycoplasma have a cell wall.
- bacterial cell wall is composed of peptidoglycan which is a large molecure of alternating units of two amino-containing carbohydrate: N-acetylglucosamine and N-acetyleneuramic acid joined by amino acids (forming peptide bonds); 60%-90% of cell wall is peptidoglycan
cell wall of gram+ (stained blue/purple) is different than cell wall of gram- (stained red/pink). In gram+, the peptidoglycan is about 25nm with teichoic acid; in contrast, in gram-, the peptidoglycan is 3nm with polysaccharide protein lipids.
gram- cell wall is thinner but more complex with more constituents
most bacteria can be stained with Gram Staining technique; exceptions include TB (needs Acid Fast technique)
Penicillin will prevent newly-produced cells from constructing cell wall leading to destruction of bacterial cell.
(found in human tears and saliva) destroys existing cells by attacking linkage between carbohydrates and peptidoglycan in cell wall
destruction of cell wall leads to destruction of cell