Ch:16 Transcription

Question 1

Transcription proceeds under the control of ________. This enzyme will separate the two DNA strands and nucleotides are joined together as they base-pair along the DNA template strand. Unlike DNA polymerase, no primer is needed thus a chain can start from scratch.

Answer 1

RNA polymerase

Question 2

RNA polymerases bind to an area called the ______.

Answer 2

Promoter (initiates transcription)

The promoter is simply where RNA polymerase attaches and initiates transcription

Question 3

What are the 3 stages of transcription?

Answer 3

Initiation: promoter binding occurs and the DNA helix unwinds and the enzyme initiates RNA synthesis.

Elongation: RNA nucleotides are added to the 3’ end of the growing chain

Termination: Detachment of RNA polymerase occurs and our new RNA transcript is released and is now mRNA, which now diffuse away from the DNA template

Question 4

Give an overview of transcription:

Answer 4

Transcription produces mRNA will leave the nucleus to continue onto the process called translation

Question 5

Unlike DNA polymerase, RNA polymerase does not _____________… thus more errors occur during transcription than for replication. Luckily, an error during transcription gives a “bad” protein and not transmitted to the entire progeny if it occurred with DNA.

Answer 5

proof read for errors

“ALWAYS A COMMON EXAM QUESTION!!”

Question 6

At the end of transcription a cap is put on the _’ and a polyA tail is added to our _’ end.

Answer 6

5’ cap

3’ polyA tail (bunch of adenines)

Question 7

What is the complex that splices introns out called?

Answer 7

The spliceosome

Question 8

What proteins form the spliceosome?

Answer 8

snRNP’s