Protein Synthesis Inhibitors (General)

Question 1

Drugs tha selectively inhibit bacterial protein synthesis:

Answer 1

1. Chloramphenicol
2. Tetracyclines
3. Macrolides
4. Clindamycin
5. Streptogramins
6. Linezolid

Question 2

do microorganisms and mamalian cells have the same process of protein synthesis?

Answer 2

NOPE

Question 3

what kind of ribosomes does bacteria have?

Answer 3

70S

Question 4

What kind of ribososme does mamalian cells have?

Answer 4

80S

Question 5

What are the basis for selective toxicity against microorganisms without causing major effects on mamalian cells?

Answer 5

Differences in:
- Ribosomal subunits
- Chemical composition
- Functional specificities of component nucleic acids and proteins

Question 6

Broad spectrum protein synthesis inhibitors

Answer 6

• Chloramphenicol
• Tetracyclines

Question 7

Moderate spectrum protein synthesis inihibitors

Answer 7

• Macrolides
• Ketolides

Question 8

Narrow spectrum protein synthesis inhibitors

Answer 8

• Lincosamide
• Streptogramins
• Linezolid

Question 9

first inhibitors of bacterial protein synthesis
to be discovered

Answer 9

• Chloramphenicol
• Tetracyclines
• Aminoglycosides

Question 9

an older macrolide antibiotic, has
a narrower spectrum of action but continues to be active against several important pathogens

Answer 9

Erythromycin

Question 10

semisynthetic macrolides, have some distinctive properties compared with erythromycin

Answer 10

• Azithromycin
• Clarithromycin
• Clindamycin

Question 11

Newer inhibitors ofmicrobial protein synthesis, have activity against certain bacteria that have developed resistance to older antibiotics.

Answer 11

• streptogramins
• linezolid
• telithromycin
• tigecycline (tetracycline analog)

Question 11

The binding site of most of the antibiotics reviewed in this chapter are on the ____ ribosonal subunit except tetracyclines

Answer 11

50s

Question 12

The binding site of tetracyclines are on the ____ ribosomal subunit

Answer 12

30S

Question 13

transpeptidation is catalyzed by what enzyme

Answer 13

peptidyl transferase

Question 14

inhibits transpeptidation by blocking the binding of the aminoacyl moiety of the charged transfer RNA (tRNA) to the acceptor site of the mRNA complex.

Answer 14

Chloramphenicol

Question 15

Most of the antibiotics reviewed in this chapter are bacteriostatic inhibitors of protein synthesis acting at the ribosomal level except:

Answer 15

• streptogramins
• oxazolidinones
• pleuromutilins

Question 16

They bind to the 50S ribosomal subunit, constricting the
exit channel on the ribosome through which nascent polypeptides are extruded. In addition, tRNA synthetase activity is inhibited, leading to a decrease in free tRNA within the cell.

Answer 16

Streptogramins

Question 17

binds to the unique site in the 50s ribosome, inhibiting initiation by blocking formation of the tRNA-ribosome-mRNA ternary complex

Answer 17

Linezolid

Question 18

bind to the 30S ribosomal subunit preventing
binding of amino acid-charged tRNA to the acceptor site of the
ribosome-mRNA complex.

Answer 18

Tetracyclines

Question 19

can inhibit the functions of
mitochondrial ribosomes, which contain 70S ribosomal RNA.

Answer 19

Chloramphenicol

Question 20

have little effect on mammalian protein synthesis because an active efflux mechanism prevents their intracellular
accumulation.

Answer 20

Tetracyclines

Question 21

Steps in bacterial protein synthesis:

Answer 21

1. tRNA carrying amino acid 6 binds to acceptor site of ribosome
2. The peptidyl tRNA at the donor site with amino acid 1-5 binding to the amino acid 6 (transpeptidation)
3. The uncharged tRNA at the donor site is released
4. The new six amino acid chain with its tRNA shifts to the peptidyl site