Antibiotics: gross mechanism of action

Question 1

The diagram summarises the gross mechanism of action of the commonly used antibiotics.

Answer 1

Question 2

Inhibits cell wall formation?

Answer 2

peptidoglycan cross-linking: penicillins, ​

• cephalosporins,
• carbopenems

peptidoglycan synthesis:

• glycopeptides (e.g. vancomycin)

Question 3

Inhibits protein synthesis (by acting on the ribosome)?

Answer 3

50S subunit: macrolides,

• chloramphenicol,
• clindamycin,
• linezolid,
• streptogrammins

30S subunit:

• aminoglycosides,
• tetracyclines

Question 4

Inhibits DNA synthesis?

Answer 4

quinolones ​

• (e.g. ciprofloxacin)

Question 5

Damages DNA?

Answer 5

metronidazole

Question 6

Inhibits folic acid formation?

Answer 6

• sulphonamides
• trimethoprim

Question 7

Inhibits RNA synthesis?

Answer 7

rifampicin