Final answer:
Active transport in biology involves protein pumps that use ATP to move molecules against their concentration gradient.
Step-by-step explanation:
The subject of this question is Biology.
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. This process is important for maintaining homeostasis and regulating the movement of materials in and out of cells.
One example of an active transport protein pump is the sodium-potassium pump, which exchanges sodium ions for potassium ions across the plasma membrane of animal cells.