Biochem 4 FA pp74&75 (Protein Transcription)

Question 1

Which end of the tRNA does Aminoacyl-tRNA synthetase attach the amino acid to?

Answer 1

3’ end (ACC sequence)

Question 2

Where does IF-2 bind?

Answer 2

30S ribosomal subunit then the tRNA (f-Met)

Question 3

Which process provides the energy for the attachment of the prokaryotic ribosomal subunits?

Answer 3

Hydrolysis of GTP

Question 4

When is ATP used during protein synthesis? GTP?

Answer 4

ATP = Activation or charging of tRNA
GTP = Growing of peptide in ribosome

Question 5

On which ribosomal subunit is the peptidyltransferase activity located?

Answer 5

23s rRNA (50s) in prokaryotes (P site)

Question 6

What molecule is important for elongation in prokaryotes? Eukaryotes?

Answer 6

EF-2 in eukaryotes

EF-G in prokaryotes

Question 7

What two bacterial toxins inhibit EF-2?

Answer 7

Diptheria toxin

Exotoxin-A in pseudomonas

Question 8

Which antibiotics bind to the 30S subunit to inhibit initiation?

Answer 8

Aminoglycosides

Amikacin, Streptomycin, Gentamycin

Question 9

Which antibiotic binds to the 50S subunit to inhibit initiation

Answer 9

Linolazid

Question 10

Which antibiotics bind to 30S subunit after initiation to stop A-site binding?

Answer 10

Tetracyclins

-cyclin suffix

Question 11

Which antibiotic binds to the 23s rRNA to inhibit peptidyltransferase?

Answer 11

Chloramphenicol

Question 12

Which antibiotics bind to the 50s subunit to inhibit translocation

Answer 12

Macrolides (Erythromycin, Azithromycin, Clarithromycin), and Clindamycin

Question 13

What enzyme matches amino acids to tRNA?

Answer 13

Aminoacyl-tRNA synthetase