M250 Exam 2 Study Guide Questions
All Solved Correctly.
FtsZ - Answer cell division protein forms contractile ring in center of cell & recruits cell wall
synthesis machinery
MinC - Answer inhibits FtsZ polymerization
MinD - Answer membrane-bound anchor and MinC activator
MinE - Answer determines FtsZ positioning by inhibiting MinC & MinD from the center
Noc - Answer Nucleoid Occlusion
-coats chromosome; inhibits FtsZ from polymerizing over chromosome
Autolysins - Answer cell separases; peptidoglycan remodeling enzymes (break peptidoglycan
to separate daught cells)
Caulobacter crescentus - Answer -bacterium that grows in extremely nutrient-dilute water
-prosthecum ("stalk") elongates to increase SA during nutrient starvation
-strongest glue (holdfast)
-asymmetric division
Direct counting pros - Answer -accurate measurement of # of cells
-cells don't need to be culturable
-works for any sample
Direct counting cons - Answer -cells must be evenly distributed
-can't distinguish live from dead cells
Viable counting pros - Answer -measure viable cells
-colony forming units (CFU)
Viable counting cons - Answer -only works with culturable bacteria
-assumes each colony originates from single cell
, -clumping
spectrophotometry pros - Answer -quickest technique
-reliable
spectrophotometry cons - Answer -organism must be culturable
-severe clumping problems
-indirect
Flow Cytometry pros - Answer -extremely accurate
-measures size
Flow Cytometry cons - Answer -slow, expensive
-clumping
-dead cells
Generation calculation - Answer Nt=No x 2^n
n= # gen
Nt = #cells
No= # cells to
Growth rate calculation - Answer k=1/g
g --> generation time
k --> growth rate
Growth time calculation - Answer k=n/dt
n --> # gen
dt --> time
Batch culture - Answer -closed system
-no nutrients enter
-no waste prdts leave
-ex: flasks, test tubes
Continuous culture - Answer -open system
All Solved Correctly.
FtsZ - Answer cell division protein forms contractile ring in center of cell & recruits cell wall
synthesis machinery
MinC - Answer inhibits FtsZ polymerization
MinD - Answer membrane-bound anchor and MinC activator
MinE - Answer determines FtsZ positioning by inhibiting MinC & MinD from the center
Noc - Answer Nucleoid Occlusion
-coats chromosome; inhibits FtsZ from polymerizing over chromosome
Autolysins - Answer cell separases; peptidoglycan remodeling enzymes (break peptidoglycan
to separate daught cells)
Caulobacter crescentus - Answer -bacterium that grows in extremely nutrient-dilute water
-prosthecum ("stalk") elongates to increase SA during nutrient starvation
-strongest glue (holdfast)
-asymmetric division
Direct counting pros - Answer -accurate measurement of # of cells
-cells don't need to be culturable
-works for any sample
Direct counting cons - Answer -cells must be evenly distributed
-can't distinguish live from dead cells
Viable counting pros - Answer -measure viable cells
-colony forming units (CFU)
Viable counting cons - Answer -only works with culturable bacteria
-assumes each colony originates from single cell
, -clumping
spectrophotometry pros - Answer -quickest technique
-reliable
spectrophotometry cons - Answer -organism must be culturable
-severe clumping problems
-indirect
Flow Cytometry pros - Answer -extremely accurate
-measures size
Flow Cytometry cons - Answer -slow, expensive
-clumping
-dead cells
Generation calculation - Answer Nt=No x 2^n
n= # gen
Nt = #cells
No= # cells to
Growth rate calculation - Answer k=1/g
g --> generation time
k --> growth rate
Growth time calculation - Answer k=n/dt
n --> # gen
dt --> time
Batch culture - Answer -closed system
-no nutrients enter
-no waste prdts leave
-ex: flasks, test tubes
Continuous culture - Answer -open system
