Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/40

Click to flip

40 Cards in this Set

  • Front
  • Back
gas vesicles
small, spindle-shaped, gas-filled give buoyancy
impermeable to water
contain GvpA and GvpC
from 300-1000nm long
bundles of gas vesicles in cynobacteria
heterocyst:no vesicles
microcystis:TEM of longitude
acyclobacter:TEM of neg stain
arrangement of gas vesicle proteins
~97% is highly hydrophobic GvpA,tightly folded into beta-pleated sheets
~3% is alpha-helical GvpC which crosslinks the GvpA links
endospores
highly resistant, made by gram +
found in soil (bacillus)
biogenesis lead to dehydrated structure
endospores continued...
contain Ca, SASPs
remain dominant, but germinate quickly
heat, acid, base, chemical, radiation, freezing resistant
endospore-forming bacteria
both rods
bacillus:aerobic,catalase produced
clostridium:thermophilic, fermentative (65-70 deg)
endospore microscopy
highly refractive cells:developing
highly refractive particles:mature
endospore classification
terminal:comb,cluster,both
subterminal:dark, spaced
central:spaced, patterns
cross-section of bacillus megaterium endospore
spore coat
cortex(peptido + DPA)
exosporium (protein cover)
core wall (peptidoglycan)
DNA
membrane
properties of endospore core
high Ca-dipicolinate
reduces h2o content
protects from denaturation and pyrimidine dimer forming
properties of the endospore spore
has 10-25% h2o of vegetative cells
enzymes in core cant function
increase resistance to chemicals
lowers formation of damaging oxygen radicals
pH of the core
is unit lower than that of vegetative cells:
diminishes enzyme activity
stabilizes NA's
core contains high levels of SASPs(small acid-soluable proteins)
bind to DNA and conforms, resistant to pyrimidine dimer formation by UV light
portect DNA from denaturation by dry heat
function as C source
endospore development
vegetative (dark rods)
sporulating cells (light rod)
mature spore (white dots)
endospore development in stage numbers
Stage 0: dense DNA
stage 2:septum grows
stage 3:forespore formation
stage 4:dehydration
stage 5:pduction of SASP
stage 6:develop resistance
stage 7:cell lysis, release endospore
endospore germination
conversion of endospore to a vegetative cell...3 steps:
1.endospore
2.activation:hydration
3.germination:vegetative RNA
4.outgrowth:vegetative breaks thru exosporium
motility of prok
1.extension/retraction(type 4 fimbriae)
2.gas vesicles:increase or decrease, planktonic
3.glide: predation
4.flagella:whip-like,MAJORITY
gliding model
(myxococcus)
inner and outer mem, propelled by protein complex adheres to surface and with motor propels itself along helical skeletal fiber inside the cell.Driven by proton-motor force (slime)
myxococcus xanthus
twitching and gliding
coordinated by chemoreceptors
adhesion binds to substrate
pili retract and pull forward
motor drives forward motion
gliding saprospira grandis
beads on surface in helical paths:
gliding
flip and glide
street dancer rotation
saprospira grandis is a predator
salmonella typhimurium cells are trapped by flagella in slime path left by goiding of S. grandis over a surface
flagella
in prok: made of proteins anchored in cell wall of cyto mem(proton-motor force)
flagella consists of
basal body:anchors to mem and cell wall by a rod, 2 gram +, and 4 gram - rings.
hook:attached on outside to the the rod of basal body
hollow filament:head to tail
(capable of rotating 360 deg)
flagellum gram neg bacteria structure
filament
hook
L, P, MS, C, rings (=motor)
basal body:P,MS,C rings
diff bw neg and pos bacteria
pos: one ring, simple
neg:integral proteins, rings
proton turbine model of rotation
protons flow thru the static motor proteins and exert forces(attract/repel) on charges present on C and MS, spinning the rotor. ~1000 protons are required for one rotation
assembly of flagellum
begins with MS/C insertion into cyto mem, then rod P and L rings, the hook and cap. finally ~20,000 molecules of flagellin are exported from cyto, transported thru rod and hook, assembled into the helical arrangemnt that is the filament bw the end of the hook and the base of the cap.
flagellar motion
rotation propels thru aqueous
rotation is CW or CCW, reversible
prok move in response to stimuli
flagellar motion
(runs)
in single direction for some time, may increase proportionality to the intensity or favorable stimuli
flagellar motion
(tumbles)
abrupt stops with random changes in directions, increase proportionality to intensity of unfavorable stimuli
motility of prok with polar flagella
reversible:CCW to CW
unidirectional:CW, cell stops and reorients, CW
manner of movement of lophotrychous and peritrichous prok's
bundled(CCW),forward
tumbled/pushed apart (CW)
bundled(CCW),new direction
endoflagella and motility of spirochetes
propelled by movement of the axial filament ridge around the cell, corkscrews cell forward
chemotaxis
phototaxis
absence of attractant, runs are random in direction bw tumbles
presence of attractant the runs are biased and cell moves up the gradient of the attractant
chemotaxis detected and measured
capillary action with an attractant or repellent inserted into vial that contains bacteria, gradient forms by diffusion. cells move towards attractant
prok detect stimuli
receptor proteins that activate by chemicals,light,ionic strength,O2 []. interaction with signals bring on autophosphorylation, then activate internal regulatory proteins.
chemoreceptors
polar clusters form one discrete spot, lateral clusters appear as single spots. outside have diff binding sites, insides are same
scotophobic movement
movement away from darkness(towards light). thiospirillum jenens, cells absorb like at 400 & 600 & 850
photactic group movement
movement of an entire colony (rhadospirillum centenum), in petry dish with medium agar
swarming cells and colony of proteus mirabillis
cells at tedge are more rapidly motile than ones at center, move short distance away in a mass, settle down, generate new crop.
UTI and bladder infections