Oxygen cycle

• Oxygen cycle


  An essential biogeochemical cycle

  To maintain the concentration and level of oxygen in the atmosphere

  3 main reservoirs: biosphere, lithosphere, atmosphere
• Oxygen is used up in:

  Respiration

  Decomposing

  Rusting

  Combustion
• Respiration


  Process that releases energy in the presence of oxygen

  2 types of respiration: aerobic (requires oxygen), anaerobic (doesn't require oxygen)
• Decomposing 


  When plants and animals die, they decay

  This process uses up oxygen and releases carbon dioxide into the air
• Rusting


  Also called oxidation

  This process causes metals to rust

  Also uses up oxygen
• Combustion 


  Process by which fire is generated also requires oxygen as well as heat and fuel

  Also uses up oxygen and releases carbon dioxide into the air