Final answer:
Active transport is the mechanism where molecules are moved across a cell membrane against a concentration gradient, using energy in the form of ATP and proteins acting as pumps.
Step-by-step explanation:
The process that involves the movement of molecules through proteins embedded in the cell membrane and requires ATP (adenosine triphosphate) is known as active transport. This method of transport moves substances against their concentration gradient, typically from an area of lower concentration to an area of higher concentration.
Unlike passive transport, which allows molecules to move down the concentration gradient without the use of energy, active transport utilizes specific proteins in the membrane known as "pumps." These pumps consume energy in the form of ATP to move substances across the cell membrane. Passive transport, on the other hand, includes mechanisms like osmosis and facilitated diffusion, which do not require energy input.