Replication
Which domain of microorganisms uses binary fission to replicate?
Prokaryotes
What are min proteins?
They determine the placement of the Z ring and the septum
How does a prokaryotic cell want to split?
Evenly into two cells
What is generation time?
It is more than just the time that it takes for cells to physically divide and it varies on species and growth conditions
Where is MreB found?
In bacillus shaped bacteria
What are the 5 main proteins regarding the divisosome?
Zip A
FtsA
FtsZ
FtsL
FtsK
Where are min proteins located?
In the nucleoid
What would happen if there was no FtsK protein?
The chromosomes would not be able to be pulled away from the middle where the septum is
How do you calculate the number of cells?
Nn= N02n
Nn= the number of cells at any generation n
N0= the initial number of cells
n= the number of generations
What are two ways to measure bacterial growth?
Direct cell count and coulter counter
How does Zip A differ from FtsA?
Zip A only anchors the Z ring to the plasma membrane while FTsA does that as well as recruit other divisosome proteins
How do min proteins move?
They oscillate
What is the purpose of FtsZ polymerizing?
FtsZ polymerizes, or comes together, in order to form the Z ring which also determines where the septum is located
How many cells would there be after 5 generations if you started with 4 cells?
128 cells
What is the con of using a direct cell count?
The error rate is high
What allows the septum location to be determined?
FtsZ
Which protein does the min protein determine the ring and septum?
FtsZ
Where does peptidoglycan synthesis occur?
In the cytoplasm
What are the 4 points on the growth curve?
1. The Lag Phase: no increase in the number of living bacterial cells
2. The Log Phase: the exponential increase in the number of living bacterial units
3. The Stationary Phase: the plateau in the number of living bacteria cells--> the rate of cell division and death are roughly equal
4. Death or Decline Phase: the exponential decrease in the number of living bacterial cells
What is the equation N=C/DV used for?
To calculate the viable plate count
Is the divisosome found in Gram + or Gram - prokaryotes?
Both
Where is the least amount of min proteins found?
In the center where the Z ring is formed
What type of reproduction is binary fission?
Asexual reproduction
What does a growth rate of zero mean?
The rate of births equals the rate of deaths
How does a chemostat work?
It is an apparatus for sustaining microbial growth that adds feed while removing feed to reduce the risk of contamination. It can also generate air bubbles for cultures that need oxygen for growth.