Gas exchange and respiration

• Respiration


  The process that the body uses to release energy from digested food (glucose)
• Types of respiration


  • Aerobic respiration
  • Anaerobic respiration
• Aerobic respiration


  • Energy is released in the presence of oxygen
• Aerobic respiration


  Oxygen + glucose -> carbon dioxide + water + energy
• Respiration is important because the energy released is used by cells for movement, cell repair, and some is lost as heat
• Reactants for respiration


  Oxygen and glucose
• Products of respiration


  Carbon dioxide and water (+ energy)
• Where respiration occurs


  In the mitochondria
• Mitochondria


  • Inner membrane (cristae) is where respiration happens
  • Short diffusion distance for oxygen
• The body gets rid of waste carbon dioxide by breathing it out
• The body gets rid of waste water from respiration by breathing it out as water vapour
• The energy released by respiration is used by the body for growth, making new molecules, cell repair, and movement
• Experiments to test for respiration

  • Measure oxygen in vs out
  • Measure carbon dioxide in vs out
  • Measure water vapour out
  • Measure heat released
• anaerobic respiration

  respiration without oxygen
• anaerobic respiration in humans

  Glucose-> lactic acid (+ energy)
• Advantages of anaerobic respiration


  • Releases energy for muscle contraction
  • Doesn't require oxygen
• Disadvantages of anaerobic respiration


  • Doesn't produce as much energy as aerobic
  • Produces lactic acid which is toxic (causes muscle fatigue)
• Anaerobic respiration in yeast

  Glucose -> carbon dioxide + ethanol
• Aerobic respiration


  Oxygen + glucose -> water + carbon dioxide (+energy)
• Anaerobic respiration (in humans)

  Glucose -> lactic acid
• Lactic acid is toxic and causes muscle fatigue
• Anaerobic respiration occurs in the cell cytoplasm
• When walking


  Aerobic respiration is mainly happening, you can breathe in enough oxygen to meet the needs of the muscles
• When sprinting


  Anaerobic respiration is mainly happening, you cannot breathe in enough oxygen to meet the needs of the muscles
• You pant after a race to breathe in oxygen to oxidise the lactic acid
• Yeast is involved in making bread rise
• • The pH is too low (the milk goes off is insufficient)
  • It is too acidic (accept acid is killing the bacteria, the bacteria were dying is insufficient)
  • Not enough nutrients or sugar (there is no sugar left is insufficient)
• Why would you die without lungs?
• What diseases affect the lungs?
• Trachea


  Tube that carries air to and from the lungs
• Bronchioles


  Smallest tubes in the lungs
• Bronchi


  Tubes that branch off from the trachea and carry air to the lungs
• Diaphragm


  Muscle that moves to draw air in and push it out of the lungs
• Cartilage


  Flexible material that supports the structure of the lungs
• Alveoli


  Air sacs in the lungs where gas exchange occurs
• Gases moving in and out of the blood
• Parts of the respiratory system

  • A- trachea
  • B- ribs
  • C alveoli / alveolus
  • D bronchus/ bronchi
  • E – pleural membrane
  • F diaphragm
• When you breath in the chest

  volume increases, so the pressure in the lungs decreases
• When you inhale air is drawn

  into the lungs
• Parts of the respiratory system

  • (voice box)
  • (wind pipe)
  • (bronchi)
  • bronchioles
  • Pleural membrane
  • Capillaries
  • bronchiole
  • Alveolus