ch 12 Flashcards
environmental stress
big changes to the environment
adaptive change to stress
changing gene expression
moving
biofilm forming
spore/endospore creation
response to stress steps
1) sense stres
2 )react to it
3) stop response
stress response example: low phosphate in environment and e coli
47 gene regulon turns on
heat shock response
sensor: sigma factor for heat will melt and started translating bc exposed shine- delgarno
signal : DnaK (chap protein) cant degrade sigma h
response: 25% preserved integrity of cell
feedback Dnak breaks the sigma factor down
chemotaxis
move to food and away from toxins
collect signs from environment
ways of bacterial movement
swarming, gliding, twitching, swimming
swarming
bacterial move together on solid surface with flagella, bacteria bounce off eachother
gliding
smooth, on solid surface, no flagella (can have pili)
adventurous motility
single cell gliding
twitching
solid surfaces, gram -, type iv pili to move, jerky
swimming
most common ,flagella, run and tumbles
methyl accepting chemotaxis proteins - MCPs
scout for chem
detect concentration
transit signals to flagella
chemoreceptors (mcps) are specific or general
specific
default direction of flagella
counterclockwise
parts involved with chemotaxis
mcp
cheA- sensor
cheY- responce
chez-phosphate
FINISH
planktonic cell
lone wolf cell
how mircobes communicate to echoer
send chem signal
example of cell cell combination
glow squid microbes- communication makes it glow
luxl-luxR
quorum sensing
allows for certain behaviors when population exceeds a threshold
multi cell communities
communal behaviors, sessile (goopy/pool-like)
exoplymeric substances (EPS)/ EPS matrix
goopy adhesive that holds bacteria together
EPS allow for
reactions, water and nutrient absorption, waste dumping, armor
autoinducer
chemical signal
biofilms
Multicellular communities
– Exopolymeric substances (EPS) make EPS matrix
EPS matrix features
- Adhesive
- Factory where reactions take place
- Water & Nutrient absorption
- Waste exit
- Protective armo
