Dna Transcription

Question 1

Describe how initiation works in prokaryote transcription?

Answer 1

Untranslated regions have signals that trigger start of transcription
Sigma factor- tells you where initiation starts, dissociated when initiation starts

Question 2

How does termination occur in prokaryotes?

Answer 2

Hair pin loop forms, rna polymerase recognises it and falls off
Gc rich regions

Question 3

What are the 2 extra steps in eukaryotic transcription?

Answer 3

Capping- making 7 methylguanosine cap at 5’ end, gtp reacts with 5’ end so 5 to 5 bond made

Polyadenylation- 50 to 250 adenosine bases are added to the 3’ end of rna

Question 4

What type of rna works with polymerase 1?

Answer 4

Rrna

Question 5

What type of rna works with polymerase 2?

Answer 5

mRNA

Micro rna

Question 6

What type of rna works with polymerase 3?

Answer 6

riRNA

tRNA

Question 7

How do we know if a gene is on?

Answer 7

Open chromatin
Unmethylated cytosins
Acylated histones

Question 8

Describe Rhett syndrome

Answer 8

X linked dominant

Mutation in mecp2 gene which binds to methylated cpg regions so makes complexes with other proteins