Question

A patient is taking omeprazole for gastric reflux disease. Omeprazole contains a free sulfydryl group that is critical for its mechanism of action. This drug will most likely act in which one of the following ways?

(A) Reduce an existing sulfhydryl on the intestinal
proton pump.
(B) Form a disulfide bond with a methionine
on the gastric proton pump.
(C) Form a disulfide bond with a cysteine on
the gastric proton pump.
(D) Reduce an existing sulfhydryl group on the gastric proton pump.
(E) Form a disulfide bond with a cysteine on
the intestinal proton pump.

Answer 1

Omeprazole, a proton pump inhibitor, works by forming a disulfide bond with a cysteine on the gastric proton pump, which decreases stomach acid production.

Step-by-step explanation:

The patient is taking omeprazole for gastric reflux disease, and the drug's mechanism of action involves the free sulfhydryl group it contains. Omeprazole acts by forming a disulfide bond with a cysteine on the gastric proton pump. This effectively inhibits the proton pump, decreasing the amount of acid made in the stomach. The correct answer to the question is: C) Form a disulfide bond with a cysteine on the gastric proton pump.