Lecture 9 Homework Assignment 10 points Student’s score ___________/ 10
Name:_____________________________________
(Answers can be found in textbook Chapter 12 or in Lecture 9 Powerpoints)
Classify each of the drugs/antibiotics in the word bank according to its specific mechanism of action.
Mechanisms of Drug Action
Mechanism How It Works Specific drug/Antibiotic
Inhibition of bacterial cell wall synthesis
The antibiotic inhibits the formation of the peptidoglycan cell wall. The bacterial cell wall is greatly weakened and cell lysis can occur.
Inhibition of the synthesis and incorporation of mycolic acid into the cell wall of Mycobacterium species.
Mycolic acid is a waxy lipid found in the cell wall of acid-fast bacteria. The inhibition of mycolic acid greatly weakens the cell wall of acid-fast bacteria.
Inhibition of protein synthesis in bacteria
These antibiotics interact with prokaryotic ribosomes thereby stopping the translation of proteins. Bacterial cells cannot survive without protein synthesis. These drugs are broad-spectrum because both Gram (+) and Gram (-) bacteria have prokaryotic ribosomes.
Disruption of nucleic acids
These drugs interfere with DNA or RNA by blocking the synthesis of nucleotides (the building blocks of DNA and RNA), interfering with the process of replication, or stopping the process of transcription.
Disruption of the bacterial cell membrane
These drugs disrupt the integrity of the bacterial cell membrane, the membrane becomes leaky, and eventually the cell can burst.
Inhibition of folic acid synthesis
These drugs inhibit the enzymes necessary to make folic acid, a very important coenzyme needed for the full function of key enzymes in the bacterial cell.
Disruption of fungal growth
These drugs interfere with fungal growth by disrupting the fungal cell membrane, inhibiting fungal cell wall synthesis, or inhibiting fungal cell growth by binding to the microtubules thereby stopping fungal cell division.
Word Bank
Penicillin – Aminoglycosides – Cephalosporins
Quinolones – Polymyxins – Rifampin
Chloramphenicol – Sulfonamides (sulfa drugs) – Erythromycin
Bacitracin – Polyenes – Griseofulvin
Trimethoprim – Vancomycin – Ethambutol
Tetracycline – Imidazoles – Isoniazid
Word Bank
Penicillin – Aminoglycosides – Cephalosporins
Quinolones – Polymyxins – Rifampin
Chloramphenicol – Sulfonamides (sulfa drugs) – Erythromycin
Bacitracin – Polyenes – Griseofulvin
Trimethoprim – Vancomycin – Ethambutol
Tetracycline – Imidazoles – Isoniazid