Inside the office, the concentration of sodium ions is very low. The workers inside need some of those sodium ions to balance their systems, but there’s a problem: In normal diffusion, things move from crowded to less crowded. But here, the cell needs to move sodium ions against that natural flow—from the less crowded inside to the very crowded outside!
A molecule of ATP comes along and donates a phosphate group (a tiny energy packet) to the pump. This energy changes the shape of the protein channel. active transport via a protein channel
The pump is now in its “open to the outside” shape. It loves potassium ions (K⁺). It grabs two potassium ions from outside. Inside the office, the concentration of sodium ions