AP BIOLOGY

Detailed explanation-1: -Pumps are a kind of active transport which pump ions and molecules against their concentration gradient. Active transport requires energy input in the form of ATP. Much like passive diffusion, protein pumps are specific for certain molecules.

Detailed explanation-2: -During active transport, a protein pump uses energy, in the form of ATP, to move molecules from an area of low concentration to an area of high concentration. An example of active transport is the sodium-potassium pump, which moves sodium ions to the outside of the cell and potassium ions to the inside of the cell.

Detailed explanation-3: -To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells.

Detailed explanation-4: -Exocytosis, endocytosis and sodium-potassium pump are a few examples of active transport.

Detailed explanation-5: -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.