AP BIOLOGY

Detailed explanation-1: -The sodium-potassium pump system moves sodium and potassium ions against large concentration gradients. It moves two potassium ions into the cell where potassium levels are high, and pumps three sodium ions out of the cell and into the extracellular fluid.

Detailed explanation-2: -The sodium-potassium pump carries out a form of active transport-that is, its pumping of ions against their gradients requires the addition of energy from an outside source. That source is adenosine triphosphate (ATP), the principal energy-carrying molecule of the cell.

Detailed explanation-3: -The sodium and potassium move against the concentration gradients. The Na+ K+-ATPase pump maintains the gradient of a higher concentration of sodium extracellularly and a higher level of potassium intracellularly.

Detailed explanation-4: -The sodium-potassium pump cycle The sodium-potassium pump transports sodium out of and potassium into the cell in a repeating cycle of conformational (shape) changes. In each cycle, three sodium ions exit the cell, while two potassium ions enter.

Detailed explanation-5: -To move these molecules against their concentration gradient, a carrier protein is needed. The sodium-potassium pump is an active transport pump that exchanges sodium ions for potassium ions. The pump is found in the plasma membrane of almost every human cell and is common to all cellular life.