Cell Wall

cell wall

prevents bacterial cells from rupturing

cell wall

serves as a point of anchorage for flagella

cell wall

primary site of action for several antibiotics especially B lactams

Peptidoglycan

common targets of antibiotics like penicillin

Peptidoglycan

consist of repeating disaccharide connected by polypeptides to form a lattice that surrounds and protects the cell

peptidoglycan layer

serves as a protective barrier for basterial cell

peptidoglycan layer

helps prevent the cell from bursting

murein

another name of peptidoglycan

NAG (N-acetylglucosamine)

source of carbohydrate of bacterial cell

NAM (N-acetylmuramic acid)

attatchment of polypeptide chains of peptidoglycan

NAG (N-acetylglucosamine)

provides the carbohydrate portion

NAG and NAM

sugar molecules that takes half of the peptidoglycan

Gram positive cell wall

retains crystal violet stain

Gram positive cell wall

consist of many layers of thick peptidoglycan

Gram positive cell wall

contains teichoic acids

teichoic acid

role in cell growth; prevents wall breakdown; antigenic determinants

antigenic determinants

molecular structures embedded at their peptidoglycan

antigenic determinants

can be recognize by the host immune system

antigenic determinants

determines what kind of bacteria

crystal violet, iodine, alcohol, safranin

gram staining process steps: application of:

Gram negative cell wall

thin layer of peptidoglycan, forms a mesh like structure

Gram negative cell wall

located in periplasmic space, bet. inner and outer cell membranes

Gram negative cell wall

does not contain teichoic acid

Gram negative cell wall

more susceptible to mechanical breakage

Gram negative cell wall

contains lipopolysaccharides

lipopolysaccharides (LPS)

large complex molecule that contains lipids and carbohydrates

Lipid A

symptoms/ infection associated

Lipid A

trigger a strong immune response when released into the hosts blood stream

Core oligosaccharide

this region consist of a few sugar molecules and is linked to lipid A

Core oligosaccharide

stablize the outer membrane

O-polysaccharide (O-antigen)

resist to undergo phagocytosis

O-polysaccharide (O-antigen)

outermost part of LPS and is highly variable among different gram negative species and strains

O-polysaccharide (O-antigen)

plays a role in antigenic variation and can be used to classify and identify bacterial strains

Periplasmic space

the peptidoglycan layer and the space bet. the inner and outer membranes form:

Periplasmic space

contains various enzymes and proteins involved in nutrient acquisition, energy metabolism, and defense mechanisms

Outer membrane

barrier for detergents, heavy metals, bile salts, certain dyes, antibiotics (e.g penicillin) and digestive enzymes such as lysozyme

atypical cell walls

mostly in archaea and mycoplasma

atypical cell walls

cells that have no cell wall or have very little material

atypical cell wall

do not contain peptidoglycan

pseudopeptidoglycan and s-layers

atypical cell wall contain:

s-layers

forms the outermost part of their cell wall

s-layers

provide structural support and protection

mycoplasma cell walls

group of bacteria that are known for their lack of a peptidoglycan cell wall

mycoplasma cell wall

unique sterol containing

mycoplasma cell wall

smallest group of bacteria (often parasitic)

acid fast cell wall

cell wall of mycoplasma

acid fast cell wall

high concentration of mycotic acid

mycolic acid

prevents the actives of lyes

acid stain

contain high concentration of mycolic acid

acid fast bacteria

can be stained with carbol fuchsin using the Zeihl-Neelsen stain

carbol fuchsin using the Zeihl-Neelsen stain

has phenol so it penetrates

carbol fuchsin using the Zeihl-Neelsen stain

hot staining method