Question

The proton pumps in your stomach are examples of active transport. How do
these pumps work? Is this primary or secondary active transport?

Answer 1

Proton pumps in the stomach, specifically the H⁺/K⁺ ATPase, are responsible for the secretion of hydrochloric acid (HCl) into the gastric lumen. Here’s how they work:

1. **Mechanism**: The proton pump translocates hydrogen ions (H⁺) from the epithelial cells of the stomach lining into the gastric lumen in exchange for potassium ions (K⁺). This process involves the hydrolysis of ATP, which provides the necessary energy for the movement of ions against their concentration gradients.

2. **Primary Active Transport**: The H⁺/K⁺ ATPase is an example of primary active transport. In primary active transport, the energy required to move ions against their concentration gradient comes directly from the hydrolysis of ATP. Here, ATP is converted to ADP and inorganic phosphate during the pumping action, which drives the transportation of H⁺ out of the cell.

To summarize, the proton pumps in your stomach work by actively transporting hydrogen ions out of the cells using energy from ATP hydrolysis, categorizing them as primary active transport mechanisms.