Lecture 1B: Introduction to Microbial Physiology and Prokaryotic Cell Structures Flashcards
Flagella is present in
Bacteria
Flagella counter part of archea
Archaella
structure that assists in swimming in Bacteria and Archaea
Flagella/archaella
Size of Flagellar and Flagellation
long, thin appendages (15–20 nm wide)
Different arrangements of Flagellar and Flagellation
polar
lophotrichous
amphitrichous
peritrichous
increase or decrease rotational speed relative to strength of proton motive force
Flagellar and flagellation
Shape of flagellar structure
Helical shape
Component of Filament
flagellin
Structures of flagella
- L-ring
- P-ring
- MS ring
- C-ring
attaches/stabilizes the flagellum
- close to the hook
- on the Lipid part
L-ring
Secures the rest of basal body (rod) on the Periplasmic place or peptidoglycan
P-ring
Hold together all of the components
- there are Fli proteins
- close to membrane
MS ring
Flagellar synthesis, which structure is created first on flagellum?
MS ring
Growth of flagellum tip is ___ grows from ___
Filament grows from tip
The domain organization of selected histidine- aspartate-phosphorelay systems
Osmolarity sensing
Oxygen sensing
Chemosensory
Sporulation regulation
The EnvZ/OmpR pathway of Escherichia coli, which is involved in regulating the expression of the two outermembrane porins ___ and ___.
OmpF and OmpC.
what does Osmolarity sensing promote?
Transcription
What does ArcB and ArcB system result to?
Transcription
What does CheA and CheB produce?
Receptor adaptaion
if CheY rather than CheB motility
Major proteins in chemosensory system of E. coli
- Chemoreceptors
- PBP (Periplasmic binding protein)
- Chemotaxis proteins
- Response regulator
The chemoreceptors in Chemosensory system of E. coli
methyl-accepting chemotaxis
proteins (MCPs)
Chemotaxis protein in Chemosensry system of E. coli
(Che)W monomers, CheA dimer
Response regulator of chemosensory system of E. coli
CheY
When there is a decrease in attractant conc. it will induce ____
Autophosphorylation of Che dimer
Results of phosphorylation of Che dimer (CheA and CheZ)
CheY
binds to the motor of flagella, results in change of direction
CheY
Resets flagella
CheB
How does CheB resets flagellar motor
competes with Che R, CheR will give methyl to MCP
composed of sevveral different filament proteins with little homology to bacterial flagellin
Archaella
The motility that is present in bacteria only; no archaea
- Slower and smoother than swimming
- Movement typically occurs away from
colony.
- Requires surface contact
Gliding motility
Mechanisms of Gliding motility
- Excretion of polysaccharide slime
- type IV twitching motility
- gliding-specific proteins
directed movement in response to chemical or physical gradients
Taxis
response to chemicals
Chemotaxis
Response to light
Phototaxis
Response to air
Aerotaxis
response to ionic strength
osmotaxis
response to water
Hydrotaxis
best studied in E. coli
- run and tumble behavior
Chemotaxis
How is chemotaxis moved
Rotation
smooth forward motion, flagellar motor rotates CLOCKWISE
Run
stops and jiggles, flagellar motor rotates CLOCKWISE, flagellar bundle comes apart
Tumble
In chemotaxis bacteria respond to _________________ difference in chemical concentration
Temporal
Chemotaxis monitor/sample environment with _______________ that sense attractants and repellents
chemoreceptors
