Respiration

• Respiration 


  The biological process that continuously releases energy from food (usually glucose). The energy released is used for heat, movement, growth, reproduction and active transport
• Aerobic respiration equation 


  Glucose + oxygen -> carbon dioxide + water + energy

  C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy
• Respiration details 


  An exothermic reaction and the sites of respiration are mitochondria which are found in the cytoplasm of animal and plant cells
• Aerobic and Anaerobic respiration 


  Aerobic - respiration in the presence of oxygen

  Anaerobic - respiration without oxygen
• We can respire anaerobically in our muscles. The equation in mammalian muscles is :

  • glucose -> lactic acid + energy
• Yeast 


  Can also respire anaerobically

  • glucose + alcohol -> carbon dioxide + energy
• Similarities between aerobic and anaerobic

  • Both produce energy
  • both use glucose as an energy source
• Differences between aerobic and anaerobic

  • Aerobic produces more energy
  • oxygen isn’t used in anaerobic
  • water isn’t produced in anaerobic
  • lactic acid is produced in anaerobic
• How anaerobic can be represented in yeast

  • Layer of oil prevents oxygen entering glucose solution
  • solution of glucose with yeast - after a period of time it is slightly warmer and contains alcohol
  • limewater - turns milky as bubbles of carbon dioxide passes through it
• Apparatus of anaerobic respiration with yeast 


  This apparatus can be used to investigate how different factors such as temperature and the type of sugars added, affect the rate of anaerobic respiration in yeast.

  
• Effect of exercise on the depth and rate of breathing

  Breathing is a process which brings air rich in oxygen into the lungs and thus supplies the oxygen the body needs for respiration. It also removes carbon dioxide produced during respiration from the body. When someone is active they will need to respire more to produce the extra energy required and it requires more oxygen
• When extra oxygen is needed

  • The depth of breathing increases and our lungs expand more, causing more oxygen to be taken in
  • The rate of breathing increases. This means we breathe more times per unit time taking in more oxygen per unit time
• Respiratory surfaces in humans

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• Adaptations of respiratory surfaces

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• Respiratory surfaces in plants

  The cells surrounding the intercellular air spaces in leaves. Also adapted by having

  • a large surface area
  • thin exchange surfaces
  • moist and permeable walls
  • a diffusion gradient caused by respiration in cells leading to the diffusing gases being in lower or higher concentrations than in the intercellular air spaces