Active Transport
- Active transport is the movement of molecules and ions through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration
- Active transport requires carrier proteins (each carrier protein being specific for a particular type of molecule or ion)
- Although facilitated diffusion also uses carrier proteins, active transport is different as it requires energy
- The energy is required to make the carrier protein change shape, allowing it to transfer the molecules or ions across the cell membrane
- The energy required is provided by ATP (adenosine triphosphate) produced during respiration. The ATP is hydrolysed to release energy
Active transport across the cell membrane