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.