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.
Because in Cytoville, everyone knew the golden rule: Passive transport is a lazy river. But primary active transport? That’s a dragon breathing fire, moving mountains against the current, one expensive, beautiful, phosphate-powered twist at a time. primary active transport
His protein coils tightened. Whump. His shape flipped inside out. Pump-O, now shaped like an open claw facing