Cellular Targets of Drug Therapy Flashcards
What are some common cellular targets of drug therapy?
- Cell wall/membrane.
- Ribosomes.
- Nucleus.
What is chemotherapy?
The treatment of disease by means of chemical (drugs) that have a specific toxic effect upon the disease-producing microorganisms, or that selectively destroy cancerous tissue.
What is the basis for selective toxicity of cell wall synthesis inhibitors?
Human cells do not have cell walls.
What is the fungal version of membrane cholesterol?
Ergosterol
What 2 enzymes create ergosterol?
Squalene epoxidase and CYP450.
What are 2 ways that fungal infections are treated by targeting ergosterol?
- Inhibiting the enzymes that create ergosterol.
2. By directly binding to ergosterol.
What are the 2 common antifungal mechanisms?
- Glucan synthase inhibitors.
2. Ergosterol inhibitors.
What is the dual function of inhibiting squalene epoxidase?
Drugs that inhibit squalene epoxidase not only reduce ergosterol synthesis but also cause a build up of squalene, which is toxic to fungal cells.
How have bacteria developed resistance towards penicillins?
By using enzymes called beta-lactamases, which break down the chemical structure of penicillin.
How do drugs that target ribosomes of bacteria inhibit protein synthesis?
By either binding to 50S or 30S subunits at either the A or P site.
What are the 2 enzymes that are inhibited with drugs that target purine synthesis?
Dihydropteroate synthase and dihydrofolate reductase (DHFR).
What are three classes of cell wall synthesis inhibitors?
- Penicillins
- Cephalosporins
- Glycopeptides
What is an example of a penicillin?
Amoxicillin
What is an example of a cephalosporin?
Cephalexin
What is an example of a glycopeptide?
Vancomycin
