Primary Active Transport ((free)) -

Another twist—this time, the phosphate group that had been stuck to Pump-O fell off, and the protein relaxed back to its original shape. The two potassium ions were dumped, grateful and warm, into the crowded cytoplasm.

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. primary active transport

Pump-O didn't do equilibrium. He did work . Another twist—this time, the phosphate group that had

Pump-O just smiled. Or rather, he shifted his shape into something resembling a smile. Then he stomped his foot, signaling his true partner in crime: , the cell’s high-energy currency. Another twist—this time