Microbiology Chap 4 Continued

Front 1

gas vesicles

Back 1

small, spindle-shaped, gas-filled give buoyancy
impermeable to water
contain GvpA and GvpC
from 300-1000nm long

Front 2

bundles of gas vesicles in cynobacteria

Back 2

heterocyst:no vesicles
microcystis:TEM of longitude
acyclobacter:TEM of neg stain

Front 3

arrangement of gas vesicle proteins

Back 3

~97% is highly hydrophobic GvpA,tightly folded into beta-pleated sheets
~3% is alpha-helical GvpC which crosslinks the GvpA links

Front 4

endospores

Back 4

highly resistant, made by gram +
found in soil (bacillus)
biogenesis lead to dehydrated structure

Front 5

endospores continued...

Back 5

contain Ca, SASPs
remain dominant, but germinate quickly
heat, acid, base, chemical, radiation, freezing resistant

Front 6

endospore-forming bacteria

Back 6

both rods
bacillus:aerobic,catalase produced
clostridium:thermophilic, fermentative (65-70 deg)

Front 7

endospore microscopy

Back 7

highly refractive cells:developing
highly refractive particles:mature

Front 8

endospore classification

Back 8

terminal:comb,cluster,both
subterminal:dark, spaced
central:spaced, patterns

Front 9

cross-section of bacillus megaterium endospore

Back 9

spore coat
cortex(peptido + DPA)
exosporium (protein cover)
core wall (peptidoglycan)
DNA
membrane

Front 10

properties of endospore core

Back 10

high Ca-dipicolinate
reduces h2o content
protects from denaturation and pyrimidine dimer forming

Front 11

properties of the endospore spore

Back 11

has 10-25% h2o of vegetative cells
enzymes in core cant function
increase resistance to chemicals
lowers formation of damaging oxygen radicals

Front 12

pH of the core

Back 12

is unit lower than that of vegetative cells:
diminishes enzyme activity
stabilizes NA's

Front 13

core contains high levels of SASPs(small acid-soluable proteins)

Back 13

bind to DNA and conforms, resistant to pyrimidine dimer formation by UV light
portect DNA from denaturation by dry heat
function as C source

Front 14

endospore development

Back 14

vegetative (dark rods)
sporulating cells (light rod)
mature spore (white dots)

Front 15

endospore development in stage numbers

Back 15

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

Front 16

endospore germination

Back 16

conversion of endospore to a vegetative cell...3 steps:
1.endospore
2.activation:hydration
3.germination:vegetative RNA
4.outgrowth:vegetative breaks thru exosporium

Front 17

motility of prok

Back 17

1.extension/retraction(type 4 fimbriae)
2.gas vesicles:increase or decrease, planktonic
3.glide: predation
4.flagella:whip-like,MAJORITY

Front 18

gliding model
(myxococcus)

Back 18

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)

Front 19

myxococcus xanthus

Back 19

twitching and gliding
coordinated by chemoreceptors
adhesion binds to substrate
pili retract and pull forward
motor drives forward motion

Front 20

gliding saprospira grandis

Back 20

beads on surface in helical paths:
gliding
flip and glide
street dancer rotation

Front 21

saprospira grandis is a predator

Back 21

salmonella typhimurium cells are trapped by flagella in slime path left by goiding of S. grandis over a surface

Front 22

flagella

Back 22

in prok: made of proteins anchored in cell wall of cyto mem(proton-motor force)

Front 23

flagella consists of

Back 23

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)

Front 24

flagellum gram neg bacteria structure

Back 24

filament
hook
L, P, MS, C, rings (=motor)
basal body:P,MS,C rings

Front 25

diff bw neg and pos bacteria

Back 25

pos: one ring, simple
neg:integral proteins, rings

Front 26

proton turbine model of rotation

Back 26

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

Front 27

assembly of flagellum

Back 27

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.

Front 28

flagellar motion

Back 28

rotation propels thru aqueous
rotation is CW or CCW, reversible
prok move in response to stimuli

Front 29

flagellar motion
(runs)

Back 29

in single direction for some time, may increase proportionality to the intensity or favorable stimuli

Front 30

flagellar motion
(tumbles)

Back 30

abrupt stops with random changes in directions, increase proportionality to intensity of unfavorable stimuli

Front 31

motility of prok with polar flagella

Back 31

reversible:CCW to CW
unidirectional:CW, cell stops and reorients, CW

Front 32

manner of movement of lophotrychous and peritrichous prok's

Back 32

bundled(CCW),forward
tumbled/pushed apart (CW)
bundled(CCW),new direction

Front 33

endoflagella and motility of spirochetes

Back 33

propelled by movement of the axial filament ridge around the cell, corkscrews cell forward

Front 34

chemotaxis
phototaxis

Back 34

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

Front 35

chemotaxis detected and measured

Back 35

capillary action with an attractant or repellent inserted into vial that contains bacteria, gradient forms by diffusion. cells move towards attractant

Front 36

prok detect stimuli

Back 36

receptor proteins that activate by chemicals,light,ionic strength,O2 []. interaction with signals bring on autophosphorylation, then activate internal regulatory proteins.

Front 37

chemoreceptors

Back 37

polar clusters form one discrete spot, lateral clusters appear as single spots. outside have diff binding sites, insides are same

Front 38

scotophobic movement

Back 38

movement away from darkness(towards light). thiospirillum jenens, cells absorb like at 400 & 600 & 850

Front 39

photactic group movement

Back 39

movement of an entire colony (rhadospirillum centenum), in petry dish with medium agar

Front 40

swarming cells and colony of proteus mirabillis

Back 40

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