• 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

A carrier protein changing shape during active transport

• Active transport is important in:
  • The?reabsorption?of useful?molecules?and?ions?into the?blood?after filtration into the kidney tubules
  • The?absorption of some products of digestion?from the digestive tract
  • The loading of?sugar?from the?photosynthesising cells?of leaves into the?phloem tissue?for transport around the plant
  • The loading of inorganic ions from the?soil?into?root hairs