Final answer:
Omeprazole is the drug that binds to the proton pump of gastric parietal cells to inhibit hydrogen ion secretion, while Ranitidine, Famotidine, and Cimetidine are H₂-receptor antagonists that also reduce stomach acid but by a different mechanism.
Step-by-step explanation:
Drugs that bind to the proton pump of gastric parietal cells and inhibit hydrogen ion secretion include Omeprazole (Prilosec), which is in a class of medications called proton-pump inhibitors. In contrast, Ranitidine (Zantac), Famotidine (Pepcid AC), and Cimetidine (Tagamet) are classified as H₂-receptor antagonists.
Parietal cells in the stomach secrete hydrochloric acid (HCl), which is necessary for digestion. Proton-pump inhibitors like Omeprazole effectively reduce the production of stomach acid by blocking the enzyme system of these cells. This action helps in treating conditions such as peptic ulcers, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome.
In contrast, H₂ blockers like Ranitidine, Famotidine, and Cimetidine inhibit the action of histamine on the H₂ receptors of the parietal cells, thus reducing gastric acid secretion. They are used for similar conditions but through a different mechanism of action.