Primary Active | Transport

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.

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

Every morning, he’d crack his conformational knuckles and grumble, “Alright, you bums. You know the rules. Three out, two in. Against the gradient. Again .” The three sodium ions, who had been clinging

His protein coils tightened. Whump. His shape flipped inside out. 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.

The sodiums outside would shake their tiny fists. “You’ll run out of ATP soon, old man! Then we’ll flood back in!”