Antibiotics Flashcards
What do antibiotics do and where do they stem from?
they target and kill bacteria
it is a compound that is synthesized by a microorganism (bacteria or fungus) to kill bacteria
researchers may chemically modify and synthetically manufacture these naturally occurring compounds
Why is sulfur not an antibiotic
sulfur is used to treat wounds but it is not an antibiotic since it is not made by another organism
Do antibiotics kill viruses?
No, they dont
Which two antibiotic prevents the formation of cell wall and how?
Penicillin!
Penicillin inhibits cross-linking of peptidoglycan and interferes with the synthesis of cell walls
it does this by acting as a decoy of D-Ala-D-Ala and gets the transpeptidase to get bind to it
Vancomyin
- it binds to the terminal D-Ala-D-Ala dipeptide
it prevents cross-bridge formation
inhibits cross-linking of peptidoglycan
What is bacteriostatic vs bactericidal?
Bacteriostatic
- prevents them from growing
- doesn’t kill the cell
Bactericidal
- as soon as they start to grow they will get killed
Antibiotic resistance - penicillin
resistance arises due to expression of B-lacatmase
it cleaves b-lactam ring and thus inactivating the antibiotic
what family does penicillin belong to?
B-lactams
What antibiotic affects transcription gyrase enyzme and why?
Quinolones poison bacterial topoisomerases
example: Ciprofloxacin
- it is used to treat anthrax
what antibiotics affect the cell wall?
Vancomycin
- binds to D-ala
Penicillin
- acts as a decoy for topoisomerase
what antibiotics affect transcription
Ciprofloxacin
Rifamycin B
- Inhibits initiation of RNA transcription
What antibiotics affect translation
Tetracycline
- Inhibits tRNA
Chloramphenicol
- Inhibits peptidatransase
