1.2.8 Protein synthesis

Question 1

Where does transcription take place?

Answer 1

It takes place in the nucleus

Question 2

Describe the process of transcription

Answer 2

• DNA double helix unwinds and H bonds break
• The template strand is used in the production of mRNA
• mRNA is built from free RNA nucleotides
• The order of DNA exactly determines the order of RNA bases

Question 3

What is the template strand called?

Answer 3

The antisense strand

Question 4

How does the mRNA produced in transcription get to the ribosomes for translation?

Answer 4

The mRNA leaves through nuclear pores, and enters the cytoplasm, where the ribosomse are

Question 5

Describe the process of translation

Answer 5

• The ribosomes cover the mRNA at the initiation end
• A tRNA molecule carrying an amino acid has anticodons which bind to the mRNA
• As the tRNA goes across the mRNA, the amino acids form a polypeptide chain