Unit 4 Transcrption

Question 1

Phase 1 Initiation

Answer 1

1. RNA polymerase unwinds DNA helix
2. RNA polymerase binds to the promoter region

Question 2

What is a promoter region?

Answer 2

promoter region is the upstream of DNA

TATATA box

made of Ts and As cuz they have 1 less hydrogen bond so easy to break

Question 3

phase 2 elongation

Answer 3

1. RNA polymerase moves down from promoter region, synthesizing primary mRNA

USING ANTI SENSE STRAND AS TEMPLATE

Anti sense strand: 3 prime –> 5 prime
primary mRNA: 5 prime –> 3 prime
sense strand: 5 prime –> 3 prime

anti-sense strand = template strand

sense strand = coding strand

Question 4

Phase 3 Termination

Answer 4

1. RNA polymerase see’s terminator sequsnce and stops making primary mRNA

terminator seuqeuce: sequence of nucleotides that means to stop making mRNA
AAAAAAA

2. RNA polymerase fucks off to bind to another promotor region

Question 5

Phase 4 Post-transcription modifications

Answer 5

1. 5 prime cap:
   -adds 7-methyle guanisine to 5 prime head
   -protects agient degradation
   -attach signal for ribsome
2. 3 prime poly A tail:
   -Adds a bunch of A’s to 3 prime end
   -protects agienst degradation
3. Removal of introns:
   -snRNA binds to introns to and remove them
   -snRNA binds entrons together
   -all in the spliceosome = primary mRNA + snRNA

primary mRNA –> mature mRNA

Question 6

introns vs entrons

alternative splicing

Answer 6

introns: non coding parts of DNA

entrons: coding parts of DNA

alternative splicing: entrons are put together in m any diff combos = many diff proteins