Bacterial cell division Flashcards
What is binary fission
1 cell spilts into 2 cells
bacterial reproduction/cell division
archaeal
Correct order for binary fission
The cell elongates, replicates its chromosome, separates the chromosome into two parts of the cell, a septum forms at midcell. cell separated
Bacteria reproductive strategies include all of the following EXCEPT
A) binary fission
B) budding
C) multiple fission
D) formation of multinucleoid filaments that break apart into uninucleate spores
E) fusion of two bacterial cells that then split into four uninucleate cells
E) fusion of two bacterial cells that then split into four uninucleate cells
What happens during the cell division process of binary fission
signal for binary fission DNA replicates septum forms chromosomes segregate peptidoglycan synthesis
Cell division binary
Prokaryotes and Eukaryotes replicate DNA segregate DNA into daughter cells Division of cellular components Components include ribosome subunits, enzymes, and transport proteins see page 3 on power point
What is bacterial growth
increase in cell NUMBER not size
what is binary fission
1 bacteria cell splits into 2 cells (each is generation)
The ________ ________ is the length of time it takes for a population of microorganisms to double in number.
generation time
Time it takes for one round of binary fission to occur
generation time
steps of binary fission
cell elongation DNA replication septum formation complete of septum with walls cell separates
What signals binary fission
nutrient concentration
environmental conditions
check what nutrient concentrations or environmental conditions signal binary fission
nutrient-rich environment
pH neutral
What is the septum formed from
FtsZ ring
binary fission Chromosome replication start
•origin of replication in DNA
Chromosome replication initiated by
DnaA binding (initiation protein)
Which way do chromosomes replicate
bidirectional
When does chromosome replication stop
-Until reaches terminus
•Directly opposite origin
Complex containing enzymes necessary for DNA replication
replisome
•Chromosomes separate as DNA replication occurs T/F
true
Chromosome replication and partitioning happen concurrently (at the same time) T/F
True
see figure on slide called chromosome replication
The \_\_\_\_\_\_\_\_ is a group of proteins needed for DNA synthesis that assembles at the origin of replication. A) septum B) replisome C) prospore D) None of the choices are correct.
replisome
The site at which replication of DNA starts in bacterial cells is known as the \_\_\_\_\_\_\_\_. A) origin of replication B) initiation center C) replication initiation site D) start complex
a) origin of replication
•Genome replication time is independent or dependent of generation time (E Coli)
independent==means they will work separate
septum formation
inward growth of cytoplasmic membrane and cell wall
before cell wall separates into two cell
Site of septum formation minCDE
Limits z ring formation
oscillate between cell poles
During cytokinesis, a critical step in septation is the assembly of the \_\_\_\_\_\_\_\_. A) replisome B) spindle body C) Z ring D) cytoskeletal spiral
C) Z ring
Only place Z ring forms
mid cell, where there is no minCDE
What is the MinCDE?
prevent the formation of the Z-ring at poles by oscillating from pole to pole
leaves middle open
What does level high minC at poles do
blocks septum formation
What does minD do
forms filaments and interacts with plasma membrane
what does minE do
controls min D oscillation,
directs FtsZ ring formation
divisome complex
Why does Z ring form at mid cell only.
No min CDE
What happens with nucleoid occlusion for septum formation
prevents premature septum formation
Z ring forms after most daughter chromosomes separate
T/F most daughter chromosomes form before z ring forms
True
The site of septum formation in E. coli is determined by the MinCDE proteins. Which of the following statements regarding the positioning of the septum are correct?
The concentration of MinCDE proteins is lowest in the midpoint of the cell.
Which of the following statements regarding FtsZ are correct?
- FtsZ localization determines the site of cell wall growth by recruiting PBPs for peptidoglycan synthesis.
- FtsZ polymerizes to form the Z ring that determines the site of septum formation.
see slide 7
MinCDE forms Z ring that determines
site for septum formation
Divisome
The division of bacterial cell begins
What is the divisome?
division apparatus in the cell formed by Fts proteins
4 steps of septum formation
site for septum formation
assemble z ring
form cell division apparatus/machine (divisome)
Constriction of z-ring, septum forms
FtsZ
forms ring around center of cell
peptidoglycan synthesis for septum growth
FtsA ZipA
Anchor Z ring to plasma membrane
FtsK
Chromosome segregation and separation of chromosome dimers
FtsEX
Coordinate hydrolases for septum growth and cell separation
FtsW/FtsI
peptidoglycan synthesis in septum
FtsN, FtsQLB
Coordinate ring constriction with septum growth
What happens when FtsZ breaks down
cell division occurs
FtsZ functions like and is related to
polymerizes to form filaments
depolymerizes to constrict cell
Hydrolyze GTP
Highly conserved
What is FtsZ related to?
tubulin
Provides energy for polymerization/depolymerization (assembly/disassembly) of FtsZ ring
Hydrolyzes GTP
Highly conserved FtsZ
-Found in almost all eubacteria, most archaea, and organelles of eukaryotes
Microbial ________ is an increase in cell constituents that may or may not be accompanied by an increase in cell number.
growth
