Lecture 8: Cellular Division & Specalization Flashcards
how do bacteria divide?
binary fission
what does binary fission mean?
1 cell becomes 2 cells
DnaA must be ( ) once ( ) is started
inactivated, replication
what is the outcome after 10 mins of replication?
only 1 parent strand is methylated & the new strand is not
what does hemimethylation mean?
1 of the 2 is methylated
what are the 3 steps of cellular division?
- replication
- segregation
- division
what system does Caulobacter use?
par system
what does partitioning do?
helps divide chromosome to each cell
Par A vs Par B
Par B- anchors old chromosome to 1 pole
Par A- pulls new chromosome to other pole
what is the function of the divisome?
initiates division
what are Fts
cell division proteins
what is ftsZ made of?
tubulin
what is FtsA made of?
actin
what does FtsI do?
peptidoglycan synthesis
what is FtsI inhibited by?
penicillin
what is the division septum formed by?
Z ring
what proteins prevent Z ring formation & keeps Z rings away?
min proteins
what does MreB do?
maintain cell shape & recuiting RodA
what is the elongasome?
protein that allows cells to be enlongated
what does an absence of MreB cause?
coccus/rounded shape
what shape does Caulobacter form?
vibrio
what does crescentin do?
helps create curve of cell
How do you insert new peptioglycan during the cell growth process?
different shapes & insertions
where are Rod shaped bacteria inserted?
length of the cell
where does polar growth occur?
pole & then septum
where is cocci-shaped bacteria formed?
away from Z ring
what is a ghost cells?
formed cell without DNA/no chromosome
How long are the replication and generation process in E.Coli?
replication- 40 mins
generation- 20 mins
What type of division is sporulation?
asymmetric
what type of bacteria does sporulation occur in?
gram positive only
what conditions do spore form under?
unfavourable conditions
what are the 2 components of regulatory systems?
- sensor histidine kinase
- response regulator
what does sensor histidine kinase do?
senses stimuli/environment and passes it onto regulator
what does response regulator do?
phosphorylation to change conformation
what is the main function of regulatory systems?
transfer phosphate to regulator
what are the 7 steps of the sporulation cycle?
- asymmetric cell division
- engulfment
- late sporulation
- maturation
- mother cell lysis
- germination
- growth
what 2 sigma factors are in the spore?
F & G
what 2 sigma factors are in the mother cell?
E & K
Active Spo0A leads to…
toxic release
what is a biofilm?
attached cell community enclosed in a self-induced matrix
is biofilm a target of antibiotics?
no, so they are difficult to treat
what is Quorum sensing?
how bacteria talk through sensors
what is the autoinducer?
talking/signal molecule
what does AHL do?
inhibits priming
what is AI-2?
cyclic furan derivative
what is a riboswitch
RNA that acts as a repressor
what are 2 things riboswitches can block?
ribsome binding & RNA polymerase
