Bacterial gene regulation

Question 1

Main forms of development?

Answer 1

Spatial, temporal, spatiotemporal

Question 2

Spatial development?

Answer 2

different parts of cell form different structures with different functions

Question 3

Temporal development?

Answer 3

alternative states as part of life cycle

Question 4

How do developmental changes occur?

Answer 4

Changes in gene expression

Question 5

What is the most favoured carbon source by bacteria?

Answer 5

Glucose

Question 6

What is diauxic shift?

Answer 6

A shift in bacteria from using one fuel (e.g. glucose) to another fuel (e.g. lactose) and all the gene expression changes that come from that

Question 7

What is phenotypic heterogeneity?

Answer 7

Genetically identical cells with diff gene expression

Question 8

WHich three major phases of transcription can be regulated?

Answer 8

Initiation, elongation, termination

Question 9

What does the promoter do?

Answer 9

Recognised by sigma factr and RNA pol
Part of initiation

Question 10

WHat is RNA pol made up of?

Answer 10

5 subunits
2 alpha, 2 beta, 1 omega

Question 11

What is a sigma factor made up of?

Answer 11

Several diff domains of a protein

Question 12

What do the 4 domains in a sigma factor do?

Answer 12

They each recognise smthn as part of the promoter region

Question 13

What does each part of the sigma factor recognise?

Answer 13

S2 = -10
S4 = -35

Question 14

Start of bacterial transcription cycle?

Answer 14

Sigma factor recognises the promoter, and aligns the SF w/ the RNA pol

Question 15

AT what point is the sigma factor no longer required?

Answer 15

AT the initiation of transcription

Question 16

What follows the initiation of transcription?

Answer 16

ELongation, then termination

Question 17

Speed of elongation?

Answer 17

Not uniform

Question 18

What is the speed of elongation determined by?

Answer 18

DNA being transcribed and the RNA 2ndary structure, proteins bound to DNA can block it

Question 19

How can the DNA sequence being transcribed affect the speed of elongaiton?

Answer 19

Regions w/ repetitive nucleotides are more difficult to transcribe than other regions

Question 20

Where does termination occur?

Answer 20

At terminators in the DNA sequence

Question 21

Two forms of termination?

Answer 21

Intrinsic and Rho dependent

Question 22

What is intrinsic termination?

Answer 22

Terminator loop is formed within the RNA that is recognised by an RNA binding protein (NusA)

Question 23

Rho dependent termination?

Answer 23

Required Rho protein (hexomer)
Rho recognises rut site on RNA transcript
RNA winds wound Rho

Question 24

Does processing occur to prokaryotic RNA?

Answer 24

not much

Question 25

Stability of RNA in bacteria?

Answer 25

Less than in eukaryotes--> half life is v short

Question 26

Which ribosomes do RNA have, and what are they made up of?

Answer 26

70S ribosomes--> large (50S) and small (30S) subunits

Question 27

How is translation regulated in bacteria?

Answer 27

The stringent response

Question 28

When does the stringent response occur?

Answer 28

When the bacteria senses that its AAs are being depleted, it stops translation of things that are non-essential

Question 29

What is the stringent response associated with?

Answer 29

Virulence