Bacterial cell division 2

Question 1

Difference between OD and viable cell count during exponential phase?

Answer 1

OD is higher–> overestimates

Question 2

Difference between OD and viable cell count during stationary phase?

Answer 2

Viable count is higher–> OD underestimates

Question 3

Bacteriostatic antibiotics and their total and viable cell count?

Answer 3

Stops bacteria from growing, does not kill them–> diff between total cell count and viable cell count is the same (neither drops)

Question 4

Bacteriolytic antibiotics and their total and viable cell count?

Answer 4

Lyses cells–> total and viable cell count are the same
Both decrease

Question 5

Bactericidal antibiotics and their total and viable cell count?

Answer 5

Kills cells w/o lysing them
Total cell count plateaus while viable cell count drops

Question 6

What is present in the cytoplasm?

Answer 6

RNA, plasmids, ribosomes, cytoskeleton, enzymes, small molecules, nutrients

Question 7

What does chromosome organisation need to take into account?

Answer 7

Replication

Question 8

What is spatiotemporal organization?

Answer 8

The chromosome moving around as cells grow and divide

Question 9

Bacterial cell cycle?

Answer 9

Gell growth
DNA rep
Chromosome segregation
Division into daughter cells

Question 10

What grows during cell growth phase of replicaiton?

Answer 10

Cytoplasm and cell wall–> volume of the cell

Question 11

What is protein localization?

Answer 11

Proteins being targeted to specific locations in the cell

Question 12

Where could some proteins localize to?

Answer 12

One or both poles inod shaped cells (4 movement) or the midcell 4 cell division

Question 13

What complex is responsible for DNA replication in bacteria?

Answer 13

Replisome

Question 14

Where is the replication termination region?

Answer 14

Opposite the oriC

Question 15

What is the replication region called?

Answer 15

terC

Question 16

How do replication termination regions work?

Answer 16

They have permissive and non-permissive directions–> will allow replication going one direction over them but not the other
Tus protein binds to the Ter
Blocks DNA polymerase

Question 17

Which protein binds to ter sites for replication termination

Answer 17

Tus

Question 18

When can bacteria undergo multiple rounds of replication initiation?

Answer 18

In growth media where the carbon source is v efficient

Question 19

Why do bacteria undergo multiple rounds of replication initiation?

Answer 19

So the cell can grow more quickly than they can replicate chromosomes

Question 20

When does chromosome segregation occur?

Answer 20

WHile replication is occurring

Question 21

What is the divisome?

Answer 21

The machinery necessary to cut the two daughter cells in half

Question 22

How does the divisome work?

Answer 22

Z ring contracts around the middle of the cell

Question 23

Stages of cell splitting?

Answer 23

Z ring formed down middle of the cell
Formation of mature divisome
Constriction and synthesis of inward septum
Cytokinesis completion
Cell separation

Question 24

How does the Z ring only form at the midline?

Answer 24

Nucleoid occlusion

Question 25

How does nucleoid occlusion work?

Answer 25

SMLA protein binds to diff sequences within the genome Stops formation of the Z ring Z ring can only form where SLMA isn't SLMA is on outside of DNA therefore z ring can only form down the middle

Question 26

What makes up the Z ring?

Answer 26

ftsZ

Question 27

Where does ftsZ co-localise to?

Answer 27

The midcell

Question 28

How does ftsZ constrict?

Answer 28

It is a GTP binding protein

Question 29

What is ftsZ tethered to the membrane by?

Answer 29

ftsA and zipA

Question 30

What is unique ab C.jejuni?

Answer 30

Has a flagellum so has to divide away from the pole where the flagellum is present

Question 31

How do marine ectosymbionts divide?

Answer 31

Along the long edge of the cell