Bacterial cell walls and envelopes

why is it impossible for microbes to survive and grow using just glycolysis and hexose sugars

the NAD+ needed will run out and pyruvate will build up and back up

what comprises the envelope?

the cell wall and cell membrane

what is the only aspect of a bacterial cell more complex than in eukaryotic cells?

the envelope

bacterial cell walls are important in resisting changes in ______ of the ____ _____

osmolarity; external environment

electron transport machinery is associated with what structure?

the inner (cytoplasmic) face of the membrane

3 components of the cell wall peptidoglycan

glycan, tetrapaptide side chain, peptide cross-link

what is glycan

repeating N-acetyl dissacharide

what is tetrapeptide

pentapeptide with an extra D-Ala

different bacteria have different peptide ___ _____

cross-links

what are the cross links useful for to us?

targeting with anti-microbial agents

Gram-positives have _____, not _____

teichoic acids; LPS

teichoic acids are.....

variable secondary wall anionic polymers for Gram (+) bacteria (no LPS)

Gram-positives have a ______ ____ ______ at the outermost surface

+/- polysaccharide capsule

Mycobacterium have Gram ___ cell walls, but stain "___ ___" because of additional long-chain fatty acids (____ _____) on the exterior

+; acid fast; mycolic acids

mycolic acids are ______

lipids

draw the layers of the mycobacterial cell wall

3 defining characteristics of the envelope of a Gram (-) bacterium

LPS, outer membrane, periplasm

2 parts of LPS

O-antigen and Lipid A

what is O-antigen?

a highly variable polysaccharide used for strain typing

what is Lipid A?

"endotoxin"; it is bioactive, has inflammatory properties called a "virulence factor"

Describe the structural components of the envelope of Gram-negative bacterium

the carbohydrate capsule can be made of ________, or less often _____.

polysaccharide; or less often protein

the capsule aides in _____, including host cells, which can contribute to forming _____ and _____, and ___ ____

adhesion; colonies; biofilms; environmental resistance

capsules aid in evasion of the ____ ____, reduces _____, and can potentially shield ____ _____.

immune system; phagocytosis; protein antigens

capsule is a major "______"-______ _____ with epitopes being antigens important in responses to _____.

serotype specific antigen; infections

the capsule is now used in ______ ______ and newer polysaccharide-protein conjugate vaccines

polysaccharide-vaccines

a polysaccharide capsule can be visualized by ___ ___ _____ staining. The capsule (will/will not) be stained in the final image.

India ink negative; will NOT

_____ is a structure used for motility, ____ is a structure used for attachment

flagella; fibria/pilli

what kind of organisms are flagella found in?

ALL motile Gram +/- PLUS eukaryotic protozoans

fimbria/pilli are found in many Gram___

negatives

some ways flagella might be arranges on a bacterial surface

a single or polar flagellum

over the entire surface

in a cluster

flagella are composed of polymerized protein _______, who's pattern can be recognized by the ____ ____ response

flagellin; innate immune

Oral spirochetes are Gram ____ bacteria with a unique flagella located where?

negative (-); in the periplasmic space (Treptonema ssp)

what might pili or fimbriae look like?

what is a major virulence factor of pathogenic escherichias that allows for colonization of urinary tract epithelium?

pili/fimbriae

Fungi are simple _____ that posses a "cell wall" that lacks ______

eukaryotes; peptidoglycan

major component of fungal cell wall

chitin