4. Translation

Question 1

Frame shifting

Answer 1

Three different frames to read a codon sequence

Question 2

Which end is amino acid attached to

Answer 2

3’ end

Question 3

Loading amino acid on tRNA

Answer 3

1. Amino acid is adenylated with ATP (Amino Acid - PO4 - Adenine)
2. Amino acid is added onto tRNA and AMP is released

Question 4

Bond type in aminoacyl tRNA

Answer 4

Ester bond

Question 5

Editing tRNA

Answer 5

Synthesis site and Editing site - like P and E in Polymerase

Question 6

Protein synthesis direction (Protein)

Answer 6

N terminus to C terminus

Question 7

Protein synthesis direction (RNA)

Answer 7

5’ to 3’

Question 8

Ribosome size

Answer 8

70s - Prokaryote

80s - Eukaryote

Question 9

Sites in Ribosome

Answer 9

A - Aminoacyl
P - Peptidyl
E - Exit

Question 10

Initiation of Translation

Answer 10

1. Small subunit binds Methionine at P site with elF2 and GTP.
2. Small subunit recognizes poly-A-tail/5’cap complex
3. Small subunit binds to 5’ end and moves downstream till it finds the first AUG it finds - Uses ATP to move down
4. When it reaches AUG, the large subunit binds to the small subunit
5. GTP is hydrolyzed to remove all the other factors

Question 11

Elongation of Translation

Answer 11

1. The peptide ester bond between the tRNA and AA at P site is broken and the protein chain is transferred to the tRNA on the A site forming a peptide bond.
2. This release of energy moves the large subunit a codon downstream
3. The P site tRNA leaves through the E site and the small subunit follows the large subunit

Question 12

Proofreading of ribosome

Answer 12

1. tRNAs are bound to EF-tu that carries GTP
2. The GTP is hydrolyzed, pushing the tRNA onto the A site and swinging around.
3. If the hydrogen bond is strong enough, the tRNA will stick and the protein will be made

Question 13

Termination of Translation

Answer 13

1. Release factor binds to A site
2. The ester bond is hydrolyzed and the protein is released
3. Everything falls apart

Question 14

EF-tu

Answer 14

Elongation Factor thermo unstable

- Proofreading of tRNA

Question 15

hsp 70

Answer 15

Uses ATP to destabilize the protein

Question 16

hsp 60

Answer 16

A “container” that places protein inside to help re-fold it

Uses ATP to put cap on and off

Question 17

Proteasome

Answer 17

Unfoldase ring on each side with protease in the middle

Question 18

Digestion of protein

Answer 18

1. Unfoldase ring recognizes the polyubiquitin chain

2. The protein is pushed into the protease

Question 19

Pulling of Protein into protease

Answer 19

The “cap” has six subunits - like helicase

- E from hydrolysis of ATP is used to change the conformation and pull it in

Question 20

Activation of Ubiquitin Ligase

Answer 20

• Phosphorylation by protein kinase
• Allosteric transition by ligand binding
• Allosteric Transition by protein binding

Question 21

Activation of Degradation Signal

Answer 21

• Phosphorylation by protein kinase
• Unmasking by protein dissociation
• Creation of destabilizing N-terminus (Through hydrolysis)