The membrane transport mechanism that requires ATP is known as active transport.
Active transport is a process where molecules move across a cell membrane from an area of lower concentration to an area of higher concentration, against their concentration gradient. This process is crucial for maintaining the proper concentrations of ions and molecules inside and outside of cells.
Unlike passive transport, which relies on the natural movement of molecules and does not require energy, active transport uses energy derived from ATP (adenosine triphosphate). One of the most common examples of active transport is the sodium-potassium pump, which pumps sodium ions out of the cell and potassium ions into the cell, effectively using ATP to maintain essential cellular functions.