Protien Synthesis

Question 1

Name the 3 stages of protein synthesis.

Answer 1

Transcription
RNA processing
Translation

Question 2

Where does transcription occur?

Answer 2

In the nucleus

Question 3

Explain initiation of transcription

Answer 3

RNA polymerase binds to promoter reigon with the help of a TF
One strand acts as a template

Question 4

Explain elongation of transcription.

Answer 4

RNA polymerase moves from 5’ end to 3’ adding nucleotides

Question 5

Explain termination of transcription

Answer 5

RNA polymerase reaches terminator region and release RNA creating pre MRNA

Question 6

Describe RNA processing

Answer 6

Capping at 5’ end
Polyadenylation at 3’ end (adding A’s to tail)
Introns are spliced out (non coding regions)

Question 7

Where does translation take place

Answer 7

In cytoplasm on ribosome

Question 8

Describe initiation of translation

Answer 8

tRNA carrying methionine (start codon) binds to small subunit of ribosome
Ribosome binds to 5’ end as recognised the cap
Ribosomes slide along mRNA to start codon
Large sub unit binds to small so tRNA is aligned on P site

Question 9

Describe elongation of translation

Answer 9

Charged tRNA with next AA binds to ribosome
Peptide bond forms to NH2 of A site
Ribosome translocates to next codon
Spent tRNA is ejected

Question 10

Describe termination of translation

Answer 10

Finishes at stop codon (doesn’t code of AA)
Release factors bind to stop codon
Ribosome releases mRNA