Translation

Question 1

What initiates translation

Answer 1

when the mature mRNA is exported from the nucleus to the cytoplasm

Question 2

Reading Frame

Answer 2

Defines the amino acid sequence and is read from the 5’ end AUG

Question 3

What is the link between mRNA and protein

Answer 3

tRNA

Question 4

Where will the amino acid connect to on the tRNA

Answer 4

It will attach to the 3’ end

Question 5

Anticodon

Answer 5

Binds to mRNA and its antiparallel and complementary
The anti codon is 5’-3’, corresponding codon is 3-5
Ensures that the current amino acid is paired with the correct polypeptide chain

Question 6

How is the redundancy managed for translation

Answer 6

1. More than 1 tRNA for multiple amino acids
2. Some tRNA can recognize and bind to codon

Question 7

How do we ensure Fidelity

Answer 7

Aminacyl-tRNA synthetase which places correct amino acid sequence

Question 8

how is tRNA recognized by synthetase

Answer 8

1.Identifying the anticodon
2. Recognizing the acceptor arm
3. Reading 3’ and placing correct amino acid

Question 9

Where is the ribosomal structure located

Answer 9

In the endoplasmic reticulum on cytoplasm

Question 10

What is the ribosomal structure

Answer 10

Large subunit: E,P, A site
Small subunit: mRNA binding site

Question 11

What are the functions of the EPA site

Answer 11

E site: exit site where tRNA leaves
P site: peptide site where the growing polypeptide site
A site: aminoacyl site which places the next amino acid on tRNA

Question 12

Elongation and Quality Control of Translation

Answer 12

EF-TU (P) and EF1 checks the A site to make sure that the correct AA has been placed.
If it is not correct, the EF1 will not release
If it is correct, GTP will hydrolysis and EF1 will release

Question 13

What is the other elongation factor

Answer 13

EF-G or EF2 helps ribosome move more efficiently

Question 14

What are the functions of elongation function

Answer 14

Efficiency and error correcting

Question 15

EF-TU and EFG

Answer 15

EF-TU: binds to aminoacyl acid
EFG: helps ribosome move along

Question 16

What is the initiation process of translation

Answer 16

1. Shine-Dalgarno sequences bind to small subunit
2. Positioning of small subunit on the initiating codon requires initiator factors
   3.Fmethionine aminoacyl tRNA binds to start codon
3. Large subunit binds

Question 17

Initiation of Translation (E)

Answer 17

1. EIF4E eukaryotic initiator fact binds to the 5’ cap
2. EIF4G circulates the mRNA and also binds to EIF4E
3. Translation initiation factor and METinitiator tRNA bind to small subunit
4. The unit moves along to the AUG codon and large subunit attaches and initiation factors dissociate and translation can proceed

Question 18

Translation termination

Answer 18

Human releasing translation factor is a protein

Question 19

Post translation modification

Answer 19

Phosphorylation and glycosylation

Question 20

Why would covalent modifications be required

Answer 20

To make protein active
To move protein to proper organelle

Question 21

How is protein degradation controlled

Answer 21

Every protein has a small ubiquitin covalently attached to it which directs them to proteasome and they will degraded by proteases