AP BIOLOGY

Detailed explanation-1: -Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentration.

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: -The sodium-potassium pump is an example of active transport that transports Na ions out of the cell and K+ ions into the cells. Inside the cell, the concentration of K+ ions is higher than outside the cell, and the concentration of sodium ions is higher outside the cell.

Detailed explanation-4: -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.

Detailed explanation-5: -Sodium ions are “pumped” from a region of lower concentration to a region of higher concentration in the nerve cells of humans. This process is an example of: 1. diffusion.