Answer: It blocks histamine H 2 receptors in the stomach lining, reducing acid secretion at the source.
- A It directly neutralises stomach acid through its own basic hydroxide groups under typical conditions
- B It blocks histamine H<sub>2</sub> receptors in the stomach lining, reducing acid secretion at the source
- C It physically coats the stomach lining with an inert protective barrier layer according to standard textbooks
- D It speeds up the rate at which the stomach empties its contents in general practice as frequently described
Correct answer: B. It blocks histamine H<sub>2</sub> receptors in the stomach lining, reducing acid secretion at the source
Explanation: Ranitidine is a histamine H<sub>2</sub>-receptor blocker: it reduces the secretion of stomach acid in the first place, rather than simply neutralising acid already present, as basic antacids like Mg(OH)<sub>2</sub> do.
The hydrophobic hydrocarbon tail of each soap/detergent molecule dissolves into an oily dirt droplet, while the hydrophilic (ionic) head stays in the surrounding water - trapping the grease inside a micelle that rinses away with water.
Concept context
Drugs and how they interact with biological targets, chemicals in food, and cleansing agents (soaps and detergents) - chemistry applied directly to daily life and healthcare.