This pump is the bouncer of the cellular club. For every three sodium ions that try to crowd into the cell, the pump kicks them out. In exchange, it pulls two potassium ions inside.
Active transport is not merely a cellular curiosity; it is vital for organism-level function. active transport
| Feature | Passive Transport | Active Transport | | :--- | :--- | :--- | | | None (kinetic energy) | ATP, light, or redox energy | | Direction | Down gradient (high → low) | Against gradient (low → high) | | Carrier proteins | Channel proteins or uniporters | Pumps, symporters, antiporters | | Equilibrium | Reaches equilibrium | Maintains steady-state disequilibrium | | Example | O₂ diffusion, water osmosis | Na⁺/K⁺ pump, glucose uptake in intestines | This pump is the bouncer of the cellular club