Na-K Pump: Active Transport

Active Transport is active (as opposed to passive) because it uses chemical energy released by breaking off one inorganic phosphate from ATP. In the case of the Na-K Pump, that energy is used to change the shape of the membrane transport protein, thus dumping out 3 Na+ ions. This movement of sodium out of the cell is Against it’s concentration gradient, which means energy is required to drive the change of shape in the membrane protein that drops it’s bound 3 Na+ ions outside the cell. Two K+ ions are brought inside the cell with an inorganic phosphate via a co-transport mechanism, not requiring more energy, or ATP, be used. This movement of sodium and potassium across the cell membrane is essential to our body’s proper operation, or physiology. This maintains the membrane potential of a nerve cell, or neuron. Without this potential, a neuron would not fire off an action potential. We would not be able to have a single thought in our brain, let alone millions of them.