chapter 8 - molecular biology of growth

Question 1

Summarize chromosome segregation

Answer 1

• requirement for daughter cell to get a copy of genome
• using the par system

Question 2

Summarize the Par system

Answer 2

1. Pop Z localizes to old pole of the cell and associates with Par B which binds to Par S
2. Par S sequence on daughter chromosome is bound by Par B and moved to new pole by Par A

Question 3

Summarize cell division

Answer 3

1. the divisome is a cell division apparatus
2. Fts Z forms a ring around the center of cell
3. Zip A anchors Fts Z to the cytoplasmic membrane
4. Fts A recruits other Fts proteins
5. Fts I helps synthesize new peptidoglycan

Question 4

How do the Min proteins ensure the divisome forms at the center of the cell?

Answer 4

1. MinD binds MinC and together they prevent the FtsZ ring from forming.
2. MinE also oscillates pushing MinCD aside towards the pole
3. MinCD spends most of the time at the pole, allowing the FtsZ ring to form only in the center of cell.

Question 5

What determines the cell morphology?

Answer 5

1. Shape-determining proteins (SEDS)
2. MreB major shape-determining factor. it recruits other proteins involved in cell wall growth to form the elongasome in rod shaped bacteria

Question 6

What is the role of crescentin?

Answer 6

it forms filaments which gives vibrio-shaped cells their curve
it also localizes to the concave surface of the cell and is present in addition to MreB