50s Subunit

Question 1

Which of these antibiotic groups does not match its kind? Select all that apply.

A. Chloramphenicol; bacteriocidal
B. Oxazolidinones; Linezolid is the first and most used agent so far
C. Pleuromutlilins; has a tricyclic mutilin core that possesses moieties and treats anaerobic bacteria.
D. Macrolides and Ketolides; among the safest antibiotics
E. Lincosamides; Alter the drug binding site on 23S rRNA via acetylation
F. Streptogramins; are nasty medications and should only be used when it is absolutely necessary.

Answer 1

A. Chloramphenicol; bacteriocidal
Bacteriostatic
E. Lincosamides; Alter the drug binding site on 23S rRNA via acetylation
Methylation

Question 2

The flexibility of U2585 is important for what mechanism of Linezolid?
A. B only
B. the induced fit of aa-tRNA into P-site.
C. the inhibitory effect of Linezolid.
D. B and C

Answer 2

D. B and C

Question 3

Absence of which residue in eukaryotes symbolizes high specificity of Clindamycin?

Answer 3

Residue A2058

Question 4

Clindamycin binds both A- and P- sites on 50S. This prevents?

Answer 4

50S interactions with substrates and ceases progression of the growing peptide chain.

Question 5

Pleuromutilins inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit at the...?
A. Acceptor Site 
B. Peptidyl Site
C. Peptidyl transferase center (PTC)
D. Acceptor and Peptidyl Site

Answer 5

Binding at the peptidyl transferase center (PTC)

Question 6

Pleuromutilins inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit at the...?
A. Acceptor Site 
B. Peptidyl Site
C. Peptidyl transferase center (PTC)
D. Acceptor and Peptidyl Site

Answer 6

Binding at the peptidyl transferase center (PTC)

Question 7

Pleuromutilins prevent the correct positioning of the CCA ends of tRNAs thereby?

Answer 7

Inhibiting peptide bond formation

Question 8

Macrolides contain a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine. Ketolides lack of the total features?

Answer 8

Cladinose sugar

Question 9

What compensates for the loss of the cladinose sugar in ketolides?

Answer 9

Heteroaryl arm ( Literally just two different rings)

Question 10

Where is the exit tunnel located?

Answer 10

In the 50s Subunit

Question 11

Macrolides and Ketolides do NOT block the peptidyl-transferase activity. Where do Macrolides and ketolides bind?

Answer 11

Exit tunnel

Question 12

Erythromycin is a part of which family?

Answer 12

Macrolides and ketolides

Question 13

Which macrolide binds 50s at two sites?

Which sites?

Answer 13

Azithromycin binds 50S at two sites

Binds 23S rRNA residues and with the L4&L22 proteins.

Question 14

Ribosomal proteins can be denoted as
A. R protein
B. L22
C. A and B
D. Neither

Answer 14

C. R protein and L22 or any number

Question 15

Which of these macrolides is a derivative of erythromycin?

A. Azithromycin
B. Clarithromycin
C. Telithromycin
D. Troleandomycin

Answer 15

D. Troleandomycin

Question 16

Which of these drugs are more effective due to their capability to bind to ribosomal proteins?

A. Azithromycin 
B. Clarithromycin 
C. Telithromycin
D. Troleandomycin
E. A and D
F. All of the above

Answer 16

E. Azithromycin and Troleandomycin

Question 17

Quinupristin and Dalfopristin are part of which family?

Answer 17

Streptogramins

Question 18

Dalfoprisin binds within?

Answer 18

PTR

Question 19

Quinupristin is located at the entrance to the ribosomal exit tunnel of the?

Answer 19

50s subunit