Antibiotics

Question 1

Sulfonamides

Answer 1

Inhibit metabolism. Derived from prontosil. Block Folic acid synthesis (and therefore NA synthesis). Structural analog of PABA. Good selective toxicity.

Question 2

Cyclines

Answer 2

Inhibit protein synthesis. Binds aminoacyl site of 30s blocking tRNA

Question 3

Aminoglycosides

Answer 3

Inhibit protein synthesis. Interfere with formation of 30s initiation complex

Question 4

Macrolides

Answer 4

Inhibit protein synthesis. Binds to 23s component of 50s rRNA and block exit of peptide chain.

Question 5

B-Lactams

Answer 5

Inhibitors of peptidoglycan/cell wall synthesis. Has B-lactam ring. Bactericidal . Only works on replicating bacteria. Interrupt cross-linking done by transpeptidases (stop cleavage of D-alanine, which produces energy for cross linking)

Question 6

Quinolones and Fluoroquinolones

Answer 6

Inhibitors of NA synthesis. Synthetic. Inhibit DNA gyrase.

Question 7

Pyramidines (5-FC)

Answer 7

Antifungal. NA synthesis. Cytosine analog. Requires cytosine permease and cytosine deaminase to get it into cell. Narrow spectrum: yeast. Can also be anti-protozoa.

Question 8

Polyenes

Answer 8

Antifungal. Ergosterol synthesis. Fungicidal. Binds to ergosterol in membrane, destabilizing it, leading to cell lysis (osmotic integrity is gone).

Question 9

Echinocandins

Answer 9

Antifungal. Chitin synthesis. Block (1,3)-B-D-glucan synthetase, which stop creation of glucan in cell wall.

Question 10

Azole

Answer 10

Antifungal. High affinity for fungal sterols. Fungistatic or fungicidal. Target lanosterol (14a-demethylase), stopping conversion to ergosterol. Can target amoeba if they contain ergosterol. Cytoplasmic membrane.

Question 11

Neuraminidase Inhibitors

Answer 11

Work against flu virus. Neuraminidase helps with the entry (virus doesn’t get trapped in mucus) and exit (HA doesn’t bind) of the virus. Neuraminidase inhibitor will make the virus aggregate and block release into cells. Only work within first 48 hours.

Question 12

Adamantanes

Answer 12

Inhibit uncoating. Block M2 channel (M2 enables the entry of protons, releasing viral RNA from M1).

Question 13

Integrase Strand Transfer Inhibitors

Answer 13

HIV drug. Blocks integration of viral DNA into host DNA

Question 14

NRTIs and NtRTIs

Answer 14

incorporate into DNA chain and cause chain termination. Reverse transcriptase inhibitors.

Question 15

Acyclovir

Answer 15

Guanine analog. Requires viral thymidine kinase to be active. primarily active against HSV 1 and 2

Question 16

Metronidazole

Answer 16

Interferes with DNA replication. Only works with aerobic metabolism. Antiprotozoal (giardia).

Question 17

Pentamidine

Answer 17

Inhbition of protein synthesis (by targeting dihydrofolate reductase)

Question 18

Quinine

Answer 18

Interfere with parasites hematin detoxification, which is toxic to parasite. Blood schizontocides. Malaria.

Question 19

Doxycycline

Answer 19

Protein synthesis inhibitor against plasmodium (malaria). Effects mitochondrial ribosomes (70s) and interferes with apicoplast.

Question 20

Artemisinin

Answer 20

Release free radicals into parasite vacuoles, damaging the membranes. Inhibit metabolism.