Abtimicrobial agents

Question 1

what antibiotics act on cell wall and how?

Answer 1

1-B. lactam:
pencillin, cephalosporin, carbapenems, monobactams.
they act on the last steps of cell wall synthesis.

2-glycopeptide: vancomycin «first steps»
3-polypeptides: bacitricin.
4-cycloserin: sermycin «TB»

Question 2

What Antibiotics act on cell membrane?

Answer 2

1_polmyxin
2_polyene antifungals: Nystatin, amphotericin B
3_Azole antifungals: imidazole, triazole.
4_lonophores: valinomycin from streptomycetes
5_daptomycin: for systematic and life threating gram + infections.
obtained from soil saprotrophs «Streptomycetes roseosporus.

Question 3

What antibiotics act on DNA and RNA synthesis?

Answer 3

RNA: Rifampicin.

DNA: 
1_quinolones and fluroqinolones«Nalidixic acid, ofloxacin, norfloxacin, ciprofloxacin. 
2_Novobiocin 
3_metronidazole
4_Griseofulvin

Question 4

what antibiotics act on Ribosome?

Answer 4

1_inhibit protein transcription: Rifampicin, Actinomycin
2_act on 30 s:tetracycline, aminoglycosides
3_act on 50s: chloramphenicol, lincomycin, clindamycin, macrolides«erythromycin»

Question 5

what antibiotics act as metabolic analogs?

Answer 5

1_timethoprim
2_sulphonamides
3_isoniazide. 
4_PASA.  
5_Ethambutol.  TB
6_Dapsone «leprosy»