Quiz 2 BIMM 120 Practice Questions well
answered 100% correct
What are function of Fimbriae and Pilli? - correct answer ✔✔ Attachment to surfaces (Fimbriae)
and Transfer of DNA (Pili)
How fast do flagella rotate? - correct answer ✔✔ -up to300 revs/min
-don't rotate at constant speed though, varies with proton motive force
What are Flagella used for? - correct answer ✔✔ -Flagella are semirigid helical structures that
move bacteria via clockwise/counter clockwise rotation, acting like propellors on boat
What happens when Flagella rotate in one direction counter-clockwise? - correct answer ✔✔
Straight line movement occurs.
What happens when flagella rotate clockwise/change their direction of rotation? - correct
answer ✔✔ Cell will tumble and randomly change direction.
What is CheW's function in flagella motility? - correct answer ✔✔ Adapter protein mediates
communication for receptors and CheA
What is CheY's function in flagella motility? - correct answer ✔✔ -CheY (upon phosphorylation
into Che-P) will bind to flagellar switch and cause flagella to rotate clockwise and cause random,
tumbling movement
-if no CheY-P is present, then binding will not occur and CCW rotation/Straight movement will
occur instead
,What is CheZ's function in flagella motility? - correct answer ✔✔ CheZ dephosphorylates CheY-P
What is MCP's function in flagella motility? - correct answer ✔✔ -Repellants bind to MCP and
trigger phosphorylation of CheA-CheW complex w/ ATP (end result is random tumbling)
-If attractants bind, no phosphorylation of CheA-CheW complex will occur and there will be lack
of CheY-P (end result is straight movement)
Methylation
-if fully methylated, will induce auto-phosphorylation of CheA-CheW (random tumbling)
-if not completely methylated, less likely to phosphorylate CheA-CheW (straight runs)
What is CheA-CheW complex's function in flagella motility? - correct answer ✔✔ -after
repellants bind to MCP and phosphorylate the complex, CheA-CheW phosphorylates CheY and
CheB (causing clockwise rotation/tumbling)
-if attractants bind to MCP, no phosphorylation of complex occurs and as a result CheY-P will
also not be present (meaning long, straight runs will occur)
What is CheR's function in flagella motility? - correct answer ✔✔ CheR will methylate MCP
-When MCP is bound by attractant, complex is good substrate for CheR (and will continuously
methylate as a result)
-When MCP is bound by repellant, complex is bad substrate for CheR
What is CheB's function in flagella motility? - correct answer ✔✔ CheB (when phosphorylated
to CheB-P) will demethylate MCP
-When MCP is bound by attractant, complex is bad substrate for CheB
-When MCP is bound by repellant, complex is good substrate for CheB (and will continuously
demethylate as a result)
Chemotaxis can be sensed _________ - correct answer ✔✔ -Both directly and indirectly
, directly - binding to proteins
indirectly - through interactions w/ other proteins
e.g. When attractants bind MCP, MCPs is methylated
-same MCP can bind attractants and repellants
What methylates MCPs? - correct answer ✔✔ CheR
Which bacterial species produce endospores? - correct answer ✔✔ -Bacillus anthracis
-Clostridium tetani
-Clostridium botulinum
Endospore formation is known as _________ - correct answer ✔✔ sporulation, or sporogenesis
Do Archaea form spores? Yes/no? - correct answer ✔✔ No
What external factors/signals would trigger sporulation/Spo0A? - correct answer ✔✔ -
desiccation
-cell density change
-starvation
What is germination? - correct answer ✔✔ process by which mature endospore forms into
vegetative cell when conditions are favorable once again
Does germination increase # of cells? Yes/no? - correct answer ✔✔ no
answered 100% correct
What are function of Fimbriae and Pilli? - correct answer ✔✔ Attachment to surfaces (Fimbriae)
and Transfer of DNA (Pili)
How fast do flagella rotate? - correct answer ✔✔ -up to300 revs/min
-don't rotate at constant speed though, varies with proton motive force
What are Flagella used for? - correct answer ✔✔ -Flagella are semirigid helical structures that
move bacteria via clockwise/counter clockwise rotation, acting like propellors on boat
What happens when Flagella rotate in one direction counter-clockwise? - correct answer ✔✔
Straight line movement occurs.
What happens when flagella rotate clockwise/change their direction of rotation? - correct
answer ✔✔ Cell will tumble and randomly change direction.
What is CheW's function in flagella motility? - correct answer ✔✔ Adapter protein mediates
communication for receptors and CheA
What is CheY's function in flagella motility? - correct answer ✔✔ -CheY (upon phosphorylation
into Che-P) will bind to flagellar switch and cause flagella to rotate clockwise and cause random,
tumbling movement
-if no CheY-P is present, then binding will not occur and CCW rotation/Straight movement will
occur instead
,What is CheZ's function in flagella motility? - correct answer ✔✔ CheZ dephosphorylates CheY-P
What is MCP's function in flagella motility? - correct answer ✔✔ -Repellants bind to MCP and
trigger phosphorylation of CheA-CheW complex w/ ATP (end result is random tumbling)
-If attractants bind, no phosphorylation of CheA-CheW complex will occur and there will be lack
of CheY-P (end result is straight movement)
Methylation
-if fully methylated, will induce auto-phosphorylation of CheA-CheW (random tumbling)
-if not completely methylated, less likely to phosphorylate CheA-CheW (straight runs)
What is CheA-CheW complex's function in flagella motility? - correct answer ✔✔ -after
repellants bind to MCP and phosphorylate the complex, CheA-CheW phosphorylates CheY and
CheB (causing clockwise rotation/tumbling)
-if attractants bind to MCP, no phosphorylation of complex occurs and as a result CheY-P will
also not be present (meaning long, straight runs will occur)
What is CheR's function in flagella motility? - correct answer ✔✔ CheR will methylate MCP
-When MCP is bound by attractant, complex is good substrate for CheR (and will continuously
methylate as a result)
-When MCP is bound by repellant, complex is bad substrate for CheR
What is CheB's function in flagella motility? - correct answer ✔✔ CheB (when phosphorylated
to CheB-P) will demethylate MCP
-When MCP is bound by attractant, complex is bad substrate for CheB
-When MCP is bound by repellant, complex is good substrate for CheB (and will continuously
demethylate as a result)
Chemotaxis can be sensed _________ - correct answer ✔✔ -Both directly and indirectly
, directly - binding to proteins
indirectly - through interactions w/ other proteins
e.g. When attractants bind MCP, MCPs is methylated
-same MCP can bind attractants and repellants
What methylates MCPs? - correct answer ✔✔ CheR
Which bacterial species produce endospores? - correct answer ✔✔ -Bacillus anthracis
-Clostridium tetani
-Clostridium botulinum
Endospore formation is known as _________ - correct answer ✔✔ sporulation, or sporogenesis
Do Archaea form spores? Yes/no? - correct answer ✔✔ No
What external factors/signals would trigger sporulation/Spo0A? - correct answer ✔✔ -
desiccation
-cell density change
-starvation
What is germination? - correct answer ✔✔ process by which mature endospore forms into
vegetative cell when conditions are favorable once again
Does germination increase # of cells? Yes/no? - correct answer ✔✔ no
