Transport | Primary Active

Pump-O opened a special pocket on his cytoplasmic side—a docking bay labeled . The moment ATP latched on, a violent chemical reaction occurred. A phosphate group snapped off like a firecracker, releasing a surge of raw energy. The now-exhausted ADP drifted away like a spent shell casing.

The three sodium ions, who had been clinging to his interior binding sites, suddenly found themselves facing the outside world. They were ejected with a surprised “Hey!” into the extracellular fluid. primary active transport

In the sprawling, electric metropolis of Cytoville, there lived a grumpy, overworked protein named , the Sodium-Potassium Pump. He was built like a burly, two-headed bouncer, with a massive energy appetite and a permanent scowl. His job, according to the ancient cellular bylaws, was simple: kick three sodium rascals out of the club (the cell) and drag two respectable potassium citizens back in. Pump-O opened a special pocket on his cytoplasmic

The sodiums would sneer. “You can’t force us out! The concentration gradient is against you! It’s unnatural!” The now-exhausted ADP drifted away like a spent shell casing

Pump-O didn't do equilibrium. He did work .

Pump-O, now shaped like an open claw facing outward, had a new hunger: potassium. Two weary potassium ions, shivering in the cold exterior, saw the open binding sites and leaped in.