Question

Which one of the following enzymes of nucleotide metabolism is correctly paired with its pharmacologic inhibitor?

A. Dihydrofolate reductase—methotrexate

B. Inosine monophosphate dehydrogenase—hydroxyurea

C. Ribonucleotide reductase—5-fluorouracil

D. Thymidylate synthase—allopurinol

E. Xanthine oxidase—probenecid

Answer 1

A. Dihydrofolate reductase—methotrexate

Step-by-step explanation:

Dihydrofolate reductase is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid. Methotrexateis its inhibitor. It interferes with folate metabolism by acting as a competitive inhibitor of the enzyme.

Since folateis necassary for rapid dividing cells, such as cancer cells, methotrexate can be used as anticancer drug that inhibits DHFR.