Energy cycles

• Energy uses

  • Active transport
  • Muscle contraction
  • Metabolic reactions
  • Building molecules
  • Cell division
  • Maintaining body temperature
• Exothermic= releases energy

  • Making bonds
  • Energy needed to break bonds is less than energy released when bonds are made.
• Endothermic= needs energy

  • Breaking bonds.
  • Energy needed to break bonds is greater than energy needed to make bonds.
• Energy from sunlight

  Photosynthesis stores energy as chemical energy in bonds of glucose which is then metabolised into ATP where the bonds contain energy.