T3 and 4 MOA MCQ | Quizlet

1. What is the mechanism of action of imidocarb?

A. Inhibits protozoal folate synthesis

B. Disrupts protozoal DNA synthesis

C. Inhibits nucleic acid metabolism in protozoa

D. Inhibits thiamine uptake in protozoa

C

What is the mechanism of action of Diminazene?

A. Inhibits cell wall synthesis

B. Interferes with DNA synthesis in protozoa

C. Binds to 30S ribosome

D. Inhibits folate metabolism

B

What is the mechanism of action of Lasalocid?

A. Disrupts DNA replication

B. Acts as an ionophore, disrupting ion transport in protozoa

C. Inhibits mitochondrial function

D. Inhibits RNA polymerase

B

What is the mechanism of action of Narasin?

A. Blocks protozoal glucose uptake

B. Inhibits microtubule formation

C. Ionophore - alters cation gradients in protozoa

D. Inhibits protein synthesis

C

What is the mechanism of action of Monensin?

A. Acts as an ionophore, disrupting Na⁺/K⁺ balance in protozoa

B. Inhibits folic acid metabolism

C. Binds to DNA polymerase

D. Destroys parasite membranes directly

A

What is the mechanism of action of Toltrazuril?

A. Blocks ATP production

B. Inhibits DNA synthesis

C. Inhibits nuclear division and organelle development in protozoa

D. Acts as an ionophore

C

What is the mechanism of action of Amprolium?

A. Thiamine analogue - inhibits thiamine uptake in protozoa

B. Inhibits electron transport chain

C. Disrupts protein synthesis in protozoa

D. Blocks calcium ion channels

A

What is the mechanism of action of Streptomycin?

A. Inhibits bacterial DNA gyrase

B. Inhibits cell wall synthesis

C. Binds to the 30S ribosomal subunit, inhibiting protein synthesis

D. Disrupts bacterial membrane integrity

C

What is the mechanism of action of Enrofloxacin?

A. Inhibits peptidoglycan crosslinking

B. Binds to 50S ribosomal subunit

C. Inhibits DNA gyrase and topoisomerase IV, blocking DNA replication

D. Inhibits folate synthesis

C

What is the mechanism of action of Colistin (Polymyxin E)?

A. Inhibits bacterial RNA polymerase

B. Disrupts outer membrane of Gram-negative bacteria by acting as a cationic detergent

C. Inhibits DNA topoisomerase

D. Binds to 30S ribosome

B

What is the mechanism of action of Rifaximin?

A. Inhibits folic acid synthesis

B. Inhibits protein synthesis at 30S ribosome

C. Binds to and inhibits bacterial DNA-dependent RNA polymerase

D. Inhibits cell wall synthesis

C

What is the mechanism of action of Praziquantel?

A. Inhibits mitochondrial respiration in parasites

B. Blocks tubulin polymerization

C. Inhibits glucose uptake

D. Increases membrane permeability to calcium ions → causes spastic paralysis of parasites

D

What is the mechanism of action of Levamisole?

A. Inhibits glucose uptake in nematodes

B. Acts as a cholinergic ( nACHr) agonist at nematode neuromuscular junctions

C. Inhibits folic acid synthesis in parasites

D. Disrupts parasite DNA synthesis

B

What is the mechanism of action of Pyrantel?

A. Blocks acetylcholine receptors in nematodes

B. Inhibits protozoal DNA synthesis

C. Acts as a nicotinic receptor agonist → causes spastic paralysis in parasites

D. Inhibits energy metabolism in helminths

C

What is the mechanism of action of Amitraz?

A. Inhibits GABA receptors in arthropods

B. Alpha-2 adrenergic agonist → disrupts nervous system in mites and ticks

C. Blocks sodium channels in parasites

D. Inhibits chitin synthesis

B

What is the mechanism of action of Ketoconazole?

A. Inhibits fungal DNA replication

B. Forms pores in fungal membranes

C. Inhibits ergosterol synthesis by blocking 14-α-demethylase

D. Disrupts fungal protein synthesis

C

What is the mechanism of action of Amphotericin B?

A. Inhibits DNA polymerase

B. Binds to ergosterol → forms pores in fungal membranes

C. Inhibits protein synthesis in fungi

D. Inhibits fungal cell wall synthesis

B

What is the mechanism of action of Griseofulvin?

A. Inhibits ergosterol synthesis

B. Inhibits DNA replication in fungi

C. Binds to microtubules → disrupts mitosis

D. Blocks fungal cell wall synthesis

C

What is the mechanism of action of Erythromycin?

A. Inhibits DNA gyrase

B. Inhibits protein synthesis by binding to 30S ribosome

C. Inhibits cell wall synthesis

D. Inhibits protein synthesis by binding to 50S ribosomal subunit

D

What is the mechanism of action of Lincomycin?

A. Binds to 50S ribosomal subunit → inhibits protein synthesis

B. Inhibits peptidoglycan synthesis

C. Inhibits bacterial RNA polymerase

D. Disrupts bacterial membranes

A

What is the mechanism of action of Sulfadiazine?

A. Inhibits DNA polymerase

B. Inhibits dihydrofolate reductase

C. Inhibits bacterial folic acid synthesis by blocking dihydropteroate synthase

D. Binds to 30S ribosome

C

What is the mechanism of action of Oxytetracycline?

A. Inhibits DNA replication

B. Binds to 30S ribosomal subunit → inhibits protein synthesis

C. Inhibits folic acid synthesis

D. Inhibits beta-lactamase activity

B