Structure of bacterial cell

Gram(+) cell wall

thick peptidoglycane

teichoic acid, lipoteichoic acid

polysaccharides

Cell wall

Gram(-) cell wall

thin peptidoglycane

no teichoic acids

outer membrane - .molecular screen.

integral proteins

Porins

permeases,

translocation proteins

protein receptors

lipopolysaccharide LPS =

endotoxin (negative charge,

hydrophobic, anti-phagocytotic, toxic)

lipid A

core polysaccharides

O-antigen

Gram stain method

Cell wall:

Peptidoglycane or murein

network-like polymere

surrounds the cell like net bag

many layers

very rigid

Gram(+): lysozyme may break protoplast

Gram(-): penicillin may break spheroplast

L-form

Flagella

-for motility

long spiral protein chains-flagellin

Position Of flagella

Pili

- for attachment;

- for changing of

DNA between

bacteria (sex of

bacteria).