MCB 2610: Exam 3 pt. 3

are bacteria that need to reside in host eukaryotic cell stuck in the cell forever?

no

example of polymerization of actin

shigella are taken up by epithelial cells then released from vesicle and actin tail forms, they then infect another cell and continue to divide

why is polymerization of actin beneficial for pathogenic cells?

they are moving from cell to cell without hanging out in environment so they are hidden from host immune response

do the majority of bacteria have pili?

yes

adherence molecule to stick to surfaces are mediated by pili, fibers of pilin protein possess other proteins on their tips for?

sticking

a sex pilus is a different structure used for?

conjugation

sex pilus

helps 2 cells attach to one another

some scientists prefer to use pili only for conjugation structures and __ for adherence

fimbriae

pili helps during __ formation and acts as a virulence factor

biofilm

some microbes use an extension (the stalk) of the cell envelope tipped by a __ of polysaccharides

holdfast

holdfast allows bacteria to?

stick to things

stalk is generated by some genres and helps increase?

SA:V which helps cells take up or allow things to leave

glycocalyx is made up of?

capsules and slime layers and also contains s-layers

capsules and slime layers helps cells stick to things and is important in?

biofilm formation

glycocalyx aids in attachment to?

solid surfaces

glycocalyx is composed of?

polysaccharides

s layers

surface array layers and is made up of glycoproteins and lipids

capsules are composed of?

thick layers of polysaccharides

are capsules well organized?

yes and they are not easily removed from cell

capsules are visible in what type of microscope

light microscope

capsules have protective advantages such as?

protection from drying out (desiccation) and hiding out from host immune response

avirulent

no capsule; host can see microorganism

virulent

capsule; disease causing

to form a biofilm you have to?

adhere to surface and other cells

biofilms can be a single species community or multispecies community and provide protection and enhance?

survivability in harsh environments

what layers are involved in biofilm formation?

glycocalyx layers

slime layers can form polysaccharide layers which is not as thick or organized and because of this it can?

be easily removed and can't be seen under light microscope

slime layers are similar to?

capsules

slime may aid in?

motility

glycocalyx usually refers to both?

capsules and slime layers

S layers

regularly structured layers of protein or glycoprotein that self-assemble NOT A GLYCOCALYX LAYER

gram-negative bacteria the S layer adheres to?

outer membrane

gram-positive s-layer is associated with?

peptidoglycan surface

if bacteria have a layer do they have more than one?

no

s-layer of deinococcus radiodurans is highly?

structured/organized

it takes resources to make __ for s layers

proteins

proteins self assemble into s-layer which they also do for flagella; in terms of filament are any external organizing forces needed to put them in the proper orientation to form the filament?

no

interactions within __ __ themselves dictates how proteins come together

protein subunits

functions of the s-layer

protect from ion and pH fluctuations, osmotic stress, enzymes and predation, maintains shape and rigidity, promotes adhesion to surfaces, protects from host defenses and potential use in nanotechnology

due to the high organization of the s-layer functions can things cross through?

no

s-layers are crystalline array of?

interlocking proteins

can s-layers be found in both gram+/-

yes

endospore

metabolically inactive distinct structure of an organism

the bacterial endospore is resistant to?

numerous environmental conditions

the bacterial endospore is resistant to numerous environmental conditions such as?

heat, radiation, chemicals and desiccation

endospore is a particular structure formed by what bacterial species?

clostridium and bacillus

why is clostridium and bacillus producing endospores is problematic because?

they generate deadly toxins and are soil dwelling

when bacteria with endospores gets digested does it goes to an active state?

yes

metabolically active form = vegetative state which is when they?

produce the toxin that will kill you

examples of endospore locations

central, subterminal, swollen sporangium and terminal

spores develop in the?

mother cell and eventually kill it to be released out into the environment

clostridium species spores develop in what location?

swollen sporangium

why are endospores so resistant?

because of the many different layers

endospore layers from inner to outer

core, inner membrane, cell wall, cortex, outer membrane, inner coat, and outer coat

some have what layer beyond coats?

exosporium

exosporium layer

prevents stuff from environment entering

inner membrane has what receptors?

germinent

germinant receptors are important for?

when spore finds a situation to move out of spore form and back to vegetative form

cortex occupies up to half of spore volume and has?

specialized peptidoglycan that is not all cross-linked together

there is water in the cell initially and during sporulation water moves?

out of cell and instead you have CaDpa going in leading to dehydrated core

what are other things that make an endospore so resistant?

calcium, small acid-soluble DNA binding proteins, dehydrated core, spore coat and exosporium protect

peptidoglycan in cortex is associated with?

heat resistant properties

small acid-soluble DNA-binding proteins (SASPs) sit and bind to DNA blocking?

UV rays