1.2

• Aerobic respiration


  glucose + oxygen --> carbon dioxide + water + energy (ATP)
• Anaerobic respiration 


  glucose --> lactic acid + energy
• Why does anaerobic respiration produce less ATP than aerobic respiration?


  glucose is not fully broken down due to oxygen deprivation, making it less efficient
• What is respiration


  a series of enzyme controlled reactions

  aerobic - when oxygen is available

  anaerobic - oxygen is not available
• Oxygen debt


  anaerobic respiration builds up oxygen debt which has to be repaid after exercise, the amount of oxygen debt is the amount of oxygen needed to remove lactic acid
• 
  

  A - nasal cavity

  B - mouth

  C - trachea

  D - bronchus

  E - bronchiole

  F - alveoli

  G - rib

  H - intercoastal muscles

  I - diaphragm

  
• Inspiration


  1 - intercoastal muscles contract

  2 - ribs move up and out

  3 - diaphragm flattens and contracts

  4 - volume of thorax increases, pressure decreases

  5 - air is sucked in
• Expiration


  1 - intercoastal muscles relax

  2 - ribs move down and in

  3 - diaphragm relaxes and domes up

  4 - volume of thorax decreases, pressure inside increases

  5 - pressure inside higher than outside so air forced out through trachea
• Smoking 


  cilia are paralysed by tobacco smoke, so mucus sinks into lungs, and is a major contributory factor to lung cancer, the destruction of lung tissue leads to emphysema
• Tobacco


  contains:

  carcinogens - causes cancer

  tar - sticky, clogs bronchioles + alveoli

  nicotine - addictive, directly damages lungs

  carbon monoxide - makes it difficult for red blood cells to carry oxygen
• Gas exchange


  occurs at the alveoli, oxygen diffuses through the membrane
• Features of the alveoli


  moist lining - dissolves oxygen

  thin walls - short diffusion pathway

  rich blood supply - blood vessels take absorbed oxygen away
• Trachea 


  windpipe with rings of cartridge
• Bronchiole 


  small airways connected to bronchus and alveoli
• Alveoli 


  air sacks conected to bronchioles, where O2 enters blood stream and CO2 is removed through diffusion
• Pea test


  peas are left inside a thermos flask to reduce heat loss

  normal peas - respire, release heat ( 20°c -> 25°c )

  boiled peas - enzymes denature, bacteria respires ( 20°c -> 22°c )

  boiled and disinfected peas - bacteria is killed, no respiration and therefore no temperature increase ( 20°c -> 20°c )
• Emphysema

  caused by alveolar walls breaking down

  reduces surface area for gas exchange

  patient would struggle to get enough oxygen for normal activities
• Cilia


  goblet cells produce mucus which traps bacteria and particles

  ciliated epithelial cells line airway

  cilia beats and moves mucus up the trachea to swallow