Translation

Question 1

What is the role of Dicer and RISC?

Answer 1

Silencing of translation

Question 2

What are the steps used in mammalian RNAi?

Answer 2

1. Processing dsRNA NFP 21-23 Nt fragments

2. Antisense strand of siRNA guides cleavage

Question 3

How are nucleotide sequences written?

Answer 3

5’ - 3’

Question 4

What are the three stop codons?

Answer 4

UAA,UAG,UGA

Question 5

What amino acids are paired with which homopolymer?

Answer 5

UUU - Phe

AAA - Lysine

CCC - Proline

Question 6

Describe the structure of tRNA

Answer 6

Amino acid binding site (Acceptor stem)

• Aminoacyl-tRNA Synthetase reads and adds appropriate AA to stem
• VERY SPECIFIC

Anticodon Loop:
- Complementray sequence to codon which binds to mRNA codon

Question 7

Differentiate IF2 and IF3

Answer 7

IF3 Binds to small subunit and keeps it apart from large subunit

IF2 binds to initiator tRNA and brings it to P site of small subunit
* Initiator tRNA contains methionine

Question 8

What is the function of the Kozak sequence?

Answer 8

Facilitates the ID of the start codon

Question 9

How do antibiotics such as streptomycin work?

Answer 9

Inhibition of protein synthesis

Question 10

Describe the pathology of Diphteria?

Answer 10

• Produces toxin which InActivates elongations factor EF2

- Infection —> Tough leathery Membrane in pharynx