Bacterial Cell Divison And Cell Shape

Question 1

What is the Fts gene

Answer 1

Filamentous is temperature sensitive

Mutants lose activity at raised temperature

Septum only forms when the reach desired length

FtsZ is homologue of Tubulin

Question 2

How does Z ring form

Answer 2

• self assemble of Ftsz proteins at midpoint and fors a divisome 10 - 20000 strong

Question 3

What makes up the Divisome

Answer 3

Ftsa, ZipA, FtsI, FtsK and FtsZ

Question 4

Role of FtsA and ZipA

Answer 4

Stabilise and connect Z ring to inner membrane

Question 5

Role of FtsA

Answer 5

At pass and recruits other proteins

Question 6

Role of FtsI

Answer 6

Peptidoglycan synthesis and a penicillin binding protein

Question 7

Role of FtsK

Answer 7

Involved in chromosome separation

Question 8

Equation for exponential growth

Answer 8

Nt=No x 2^n
Nt = population at time t
No = initial population
N = number of generations elapsed.

Exponential growth is limited by nutrients available

Question 9

What are the two mechanisms that allow FtsZ proteins to line the middle and form z ring?

Answer 9

1. Nucleoid occlusion

2. Min genes coding MinCDE system

Question 10

Explain Nucleoid occlusion

Answer 10

• localisation of Nucleoid blocks division in their vicinity
• marks possible points for division but needs a second mechanism to ensure no mini cell formation

Question 11

Explain the different compartments of the Min system and how it occurs

Answer 11

MinC - interacts with FtsZ and inhibits Z ring

MinD - ATPase, associates membrane with MinC to make a MinCD complex

MinE binds to MinD and activates ATP hydrolysis to form a dynamic ring structure that oscillates from pole to pole

This gradient is set by the oscillations and possible midpoint is found

FtsZ is a Gtpase

Question 12

How is the Shape of a cell determined?

Answer 12

MreB proteins are actin like proteins and forms a spiral in rod bacteria underneath the membrane and sites of cell wall synthesis are throughout.

MreB is not found in cocci bacteria