Transcription

Question 1

Describe the steps in mRNA sysnthesis

Answer 1

1. Initiation-the polymerase binds to the gene
2. Elongation-the polymerase transcribes the gene
3. Termination-the polymerase stops transcribing the gene when it reaches terminator sequence. Pre mRNA produced.
4. Processing-the mature mRNA is formed
5. Export-the mRNA leaves the nucleus to be translated

Question 2

What is RNA polymerase?

Answer 2

Enzyme which makes RNA from DNA
RNA is made in the 5’-3’ direction

DNA template is read in the 3’5 direction

Question 3

What is Pol II RNA polymerase

Answer 3

used in mRNA for protein coding

Question 4

Draw and label the pol II gene

Answer 4

-

Question 5

What is special about nucleotides in RNA?

Answer 5

T is U in RNA

Question 6

What is the purpose of the promoter region?

Answer 6

It is a template for the assembly preinitiation complex, which brings pol II to the gene

Question 7

What determines the rate of transcription?

Answer 7

The rate of preinitiation complex assembly

Question 8

What are the main differences between DNA and RNA

Answer 8

DNA- Sugar deoxyribose- RNA- Ribose
RNA- T is U
DNA- double stranded helix
RNA single stranded no helix

Question 9

What is RNA capping and poly A tail

Answer 9

5’ cap is added to the first nucelotide in pre-mRNA during transcription

Poly A tail- Adenine nucleotides added to the end of mRNA
Protects mRNA from degradtion
Help export mature mRNA to the cytoplasm
helps bind proteins for translation

Question 10

Name 2 spice sites

Answer 10

GU, AG