11 - Translation

Question 1

Why do we call tRNAs decoders?

Answer 1

Each tRNA has an anticodon to a specific codon, and carries an amino acid.

Question 2

What are parts of a mature mRNA?

Answer 2

5’ cap: prevents exonuclease
RBS (ribosome binding site)
Start codon: AUG
Stop codon: UAA, UAC, UGA
3’ polyA tail

Question 3

Reason mathematically that each aa is represented by 3bases

Answer 3

if
1 base -> 1 aa -> 4 AAs 4^1
2 base -> 1 aa -> 16 AAs 4^2
3 base -> 1 aa -> 64 AAs 4^3 possibilities

Question 4

Where on the tRNA, does an amino acid bind?

Answer 4

3’ -OH

Question 5

What are codons?

Answer 5

Triplets of nucleotides

Question 6

Which enzyme is responsible for binding an amino acid to a tRNA?

Answer 6

aminoacyl tRNA synthetase

Question 7

Where does specificity of tRNAs come from?

Answer 7

Each tRNA has a specific anticodon and a specific aminoacyl-tRNA synthetase

Question 8

What are the parts of a ribosome?

Answer 8

rRNA
30s part
50s part

Question 9

What is a polysome?

Answer 9

multiple ribosomes attached to an mRNA

Question 10

What are the types of point mutations?

Answer 10

1. Non-sense: stop codon
2. Silent mutations: same aa
3. Missense mutations: different aa

Question 11

What are the different types of missense mutations?

Answer 11

conservative: similar aa
non-conservative: different

Question 12

Give an example of a disease caused by non-conservative missense mutation

Answer 12

Sickle cell anemia
Valine -> glutamic acid