Bacterial Cell Division:
What type of reproduction is bacterial cell division?
*ASEXUAL:* • Formed through mitosis. • No gametes.
Fragmentation
*ASEXUAL:* • Microbe splits into smaller fragments. • Each have same DNA as original microbe.
How is budding different from binary fission?
*ASYMMETRIC DIVISION:* • Swells up to form new cells, not constrict.
Binary fission:
*CELL DIVIDES DOWN MIDDLE:* • Septum forms. • Produces two cells. • DNA replication.
Generation time of bacteria:
*DOUBLING TIME OF A POPULATION:* • E. coli doubles in as little as 20 mins. • Tuberculosis doubles btwn. 15-20 hours.
FtsZ
*FORMS Z-RING AT CENTER OF CELL:* • Constricts cytoplasm to break wall.
Budding:
*GET TWO CELLS FROM ONE:* • Mother cell = larger. • Daughter cell = smaller. • One cell is clearly forming from the other.
What is the role of the z-ring & FtsZ in bacterial cell division?
*INITIATES SEPTUM FORMATION IN A DIVIDING CELL:* • Squeezing apart two cells.
Types of bacterial cell division:
1) Binary fission. 2) Fragmentation. 3) Budding.
Steps of binary fission
DNA replication → cell elongation → FtsZ forms z-ring in center of cell → z-ring forms divisome → forms septum that separates the daughter cells.
Cell division is directed by a protein called...
FtsZ
Calculating the number of cells:
Nn= Ni • 2n bacteria produced = (starting cell #) • 2n(# of generations in time period)
What bacteria divide by fragmentation?
• Actinomycetes. • Cyanobacteria. • Filamentous bacteria.
What is budding similar to?
• Binary fission.
What is the most common way bacteria cells divide?
• Binary fission.
FtsZ in S. areus
• Depend on FtsZ to control binary fission. • Mutants are elongated.
Filamentous cyanobacteria often divide by which of the following?
• Fragmentation.
What type of microbe buds?
• Mostly yeast. • Some cyanobacteria.
Ni
• Starting cell numbers.
n
•# of generations.