Does active transport require energy?

Active transport is a process that moves molecules across a cell membrane against their concentration gradient, meaning from an area of lower concentration to an area of higher concentration. This movement requires energy to occur because it is opposing the natural tendency of molecules to move toward equilibrium.

The primary source of energy for active transport in biological systems is adenosine triphosphate (ATP). During this process, energy is released from ATP when it is hydrolyzed (broken down). This energy is then utilized by transport proteins or pumps in the cell membrane to facilitate the movement of specific molecules, such as ions or nutrients.

In contrast to passive transport mechanisms, such as diffusion or facilitated diffusion, which rely on concentration gradients and do not require energy, active transport distinctly relies on the energy derived from ATP to drive the transport of substances. This difference underscores the critical role that energy plays in maintaining cellular homeostasis and enabling the transport of essential molecules against their natural gradients.