energydependent

Energydependent (often written energy-dependent or energy dependent) is a scientific descriptor used to indicate that a process, transport, reaction, or mechanism requires an input of energy to occur. The term is widely used in biology and chemistry and is typically contrasted with energy-independent or passive processes that proceed without external energy input.

In cell biology, energy-dependent processes include active transport, endocytosis, vesicle trafficking, and protein import into organelles. These processes rely on energy sources such as ATP hydrolysis or electrochemical gradients (proton motive force) to move substances, remodel membranes, or drive conformational changes. Examples include ion pumps like the Na+/K+ ATPase, ATP-powered transporters, and energy-requiring steps in endocytosis and exocytosis.

In pharmacology and medicine, energy-dependent transporters such as ATP-binding cassette (ABC) transporters actively efflux xenobiotics and drugs, contributing to drug resistance. Such transporters use ATP hydrolysis to move substances against their gradients, affecting the disposition and effectiveness of therapeutics.

Outside biology, energy-dependent also describes reactions or events in chemistry and physics that require an energy input to proceed beyond an activation barrier or to sustain a process, such as photoactivated reactions or electrically driven processes. The term emphasizes the role of energy input in enabling, regulating, or accelerating specific phenomena.