The Proton Pump: How Your Stomach Makes Acid
How Does Your Stomach Actually Produce Acid?
Gastric acid secretion occurs through the H,K-ATPase enzyme system (the “proton pump”) in gastric parietal cells, which actively transports hydrogen ions into the stomach lumen in exchange for potassium ions. This sophisticated molecular machinery can produce stomach acid with a pH as low as 0.8, making it one of the most acidic environments in the human body and essential for digestion, nutrient absorption, and antimicrobial defense.