Lecture 8-9 (Motility/Chemotaxis/Growth&Extremophiles) Flashcards
Which mode of bacterial motility would you expect to have on a dry surface?
A. Run-and-tumble
B. Twitching
C. Floating
D. Swimming
B.
On a bacterium with a amphitrichous flagellar organization, you would expect a flagellum on both poles of the bacterium, however, on lophotrichous arrangement you would expect multiple flagella at one pole.
T/F
True
What would be the analogous structure of MotB be in a sodium (Na+) dependent bacterial flagellum?
A. NQR
B. CheA
C. FliG
D. PomB
D.
Which of the flagellar components controls the direction of rotation?
A. MotB
B.MotA
C.Switch Complex
D. FliG
C.
In bacteria, rotation of the flagellum counter-clockwise (CCW) will result in a tumble.
T/F
False
In response to a recent increasing gradient of a chemoattractant, you would initially expect what?
A. A decreased length of run times.
B. A decreased occurrence of tumbles.
C. A decreased occurrence of runs.
D. A reversion to only smooth swimming runs.
B.
In response to being exposed to the same chemoattractant for a while, you would expect what?
A. An increase in tumble frequency.
B. A complete lack of tumbles.
C. No change because it is the same signal.
D. An increase in run duration.
A.
If CheY was no longer functional, you would expect what?
A. No flagellum rotation.
B. No effect.
C. The flagellum running CCW.
D. The flagellum running CW.
C. (The flagellar motor is inherently biased towards a counterclockwise rotation.)
If CheR was no longer functional, what would you expect?
A. CheY is not phosphorylated
B. CheA constantly phosphorylates CheY
C. CW flagellar rotation
D. MCP methylation.
D.
MCP methylation is important for the chemotaxis system’s what?
A. Excitation
B. Adaption
C. Initiation
D. Stopping motility
B.
What is the consequence if CheA is mutated (nonfunctioning)?
A. CheY doesn’t get Phosphorylated, therefore Flagellum is stuck going CCW
B. MCP is constantly OFF, therefore, Flagellum is stuck going CW
C. CheY stays phosphorylated, therefore Flagellum is stuck going CW.
CheY doesn’t get Phosphorylated, therefore Flagellum is stuck going CW
A.
What is the Flagellar rotation when CheB is mutated (Nonfunctioning)?
Always CW (Tumbling)
What is the Flagellar rotation and the consequence when MCP is mutated (Nonfunctioning)?
A. CheA is always “ON” and the the rotation is Always going CW (Tumbling)
Why is Flagellum stuck going CCW if the CheY is mutated?
(Hint: what is the consequence if CheY is mutated?)
CheA is unable to phosphorylate it. Nothing binds to the Flagellar motor complex.
Bacterial cells go through a process called meiosis, which results in 2 daughter cells.
T/F
False
A mutation (loss of function) in minD would also result in a loss of function of what?
A. MinE
B. FtsZ
C. MinC
D. Noc
C.
For a pre-existing culture of a bacterial species, what measurement method would require more culturing (growth)?
A. Viable counting
B. Direct counting
C. Flow cytometry
D. Spectrophotometry
A.
In a batch culture, you would expect optical density to be increasing when measured with a spectrophotometer in what phase?
A. death phase
B. lag phase
C. log phase
D. Stationary phase
C.
For a hyperthermophile, at what temperature would you expect its proteins to function properly at?
A. 21 degrees C (room temperature)
B. 4 degrees C
C. 37 degrees C
D. 80 degrees C
D.
A 1.____________
organism would be one that would synthesize everything from basic precursors, while a 2.____________
would require many specific compounds to grow.
Drop down box options:
Nonculturable
Fastidious
Prototrophic
Extremphile
- Prototrophic
- Fastidious
If FtsZ stopped functioning in a bacterial cell, the cell would eventually die.
T/F
True
Which phase is the growth rate greater than the death rate?
A. lag phase
B. log phase
C. Stationary phase
D. Death phase
B.
which phase has little to no growth or death?
A. lag phase
B. log phase
C. Stationary phase
D. Death phase
A.
If fresh nutrients are aded to a system continuously, what phase will it never enter?
Stationary phase
How does superoxide (Free radical) damage macromolecules usually?
It targets DNA and cuts them, damaging the DNA. Extremely lethal.
What enzyme detoxifies oxygen free radicals?
A. Catalsae (KatF)
B. Hydrolase
C. Superoxide dismutase (SodA)
D. Isomerase
C.
What enzyme converts hydrogen peroxide to water?
A. Catalsae (KatF)
B. Hydrolase
C. Superoxide dismutase (SodA)
D. Isomerase
A.
What is the consequence if minC & minD & noc were mutated (Non functioning)?
FtsZ rings would form all over, and chromosome is unprotected, therefore Cells would die.
What is the consequence if minE is mutated (Nonfunctioning)?
minC & minD would be in the middle of the cell. Therefore, FtsZ can’t find the middle to Cleave it in half. Would result in Long cells that would eventually die.
If either minE or Ftsz were mutated (Nonfunctioning) they would result in the same outcome for the cell.
T/F
True
