Polypeptide Synthesis

Question 1

What is translation?

Answer 1

Transcribes the DNA into a message (in nucules)

Question 2

Transcription initiation

STEP 1

Answer 2

1. RNA polymerase binds to the promoter region on the template strand where there is the TATA box
   - Basal transcription factors bind to promoter first to assist polyamerase bind to DNA

Question 3

Transcription elongation

STEP 2

Answer 3

1. Helicase (enzyme) causes the DNA strand to seperate
   - hydrogen bonds between strands break and seperate over a short length
2. RNA nucleotides are assembled by adding the complementary nucleotide is slowly addded to 3’ end of RNA

RNA strand gets longer due to the addition of nucleotides

Question 4

Transcription terminiation

STEP 3

Answer 4

1. Polyamerase transcribes a sequence called a terminator
2. Polyamerase molecule and mRNA strand seperate from the DNA

Question 5

Cap and Tail (pre-mRNA)

STEP 4

Answer 5

• protect transcript and assist in exporting from the nucleus and translating by ribosomes
• 5’ cap is added to the first nucleotide - protects transcript from being broken down and assists ribosome to attatch to mRNA
• polyadenylation signal shows up (enzyme) chops the RNA in two at that site (more stable, helps get exported from nucleus) - forms a poly-A-tail

Both ends of the pre-mRNA are chemically modified

5’ end is called a cap
3’ end is the tail