Control & Dynamics Of Transcription

Question 0

What is Km?

Answer 0

Km= michaelis constant
Describe affinity of an enzyme for a substrate.
- the lower the km the greater the affinity.

Question 1

What describe transcription of a gene?

Answer 1

• michaelis mention - type equation
• Hill equations
• Enzyme catalyzed reactions

Question 2

What michaelis mention - type equation describe?

Answer 2

Describe transcription

• Describe how fast a reaction occurs( enzymatic reaction ex- transcription )
• possible question is how fast the reaction changes as substrate concentration changes?

Question 3

What does Hill equation describe?

Answer 3

Describe how transcription changes as u change the cooperativity value
- the higher the ( n) the fastest reaction is. Increases the sensitivity of the enzymes to the substrate
When n= 1 the graph looks like michaelis mention graph
- n =4 graph has a sigmoid shape

Question 4

What is the ultra sensitive response?

Answer 4

Because if u change just a little the concentration of the substrate you will get a huge change reaction rate in proportion

Question 5

What does Increase in cooperativity lead to?

Answer 5

Leads to an Ultra sensitive response
- example in transcription there are multiple proteins that allows to obtain ultra sensitivity response to maintain homeostasis.

Question 6

Ways to regulate transcription in both eukaryotic and prokaryotic ?

Answer 6

Either by turning ON or OFF a gene

Question 7

What operons?

Answer 7

Genes with similar functions organized onto clusters under the regulation of one promoter
- advantage allows to deal with a series of conditions all at the same time and quickly

Question 8

What’s coordinately regulated?

Answer 8

Regulation using an OPERON

Question 9

What control transcription on prokaryotes ?

Answer 9

• Sigma factor
• Promoters
• Activator/ repressor binding proteins

Question 10

What type of repressor controls the Lac OPERON ?

Answer 10

Inducible repressor because an inducer like allolactose can bind to to the lac repressor and make the lac repressor to fall of the DNA and transcription would occur

Question 11

What are the 3 types of transcription factors?

Answer 11

Transcription factors
1- general TF
2-TF
3-Enhancer

Question 12

What are consequences sequences in eukaryotic?

Answer 12

TATA BOX
INITIATORS
CpG Island

Question 13

What consequences do.( only present in eukaryotic)

Answer 13

Tells RNA pol where transcription start site is

- tell RNA pol where the promoter is

Question 14

What transcription factors do?

Answer 14

Proteins bind to DNA and help RNA Pol bind to the promoter

• they have DNA binding domain &
• activating binding domain.
• are modular ( can be interchange )

Question 15

What is the pre- initiation complex?

Answer 15

Special name given when the general transcription factors and RNA Pol 2 are bound.