O2

• when oxygen binds to haem group, tertiary structure changes
• at low partial pressure of oxygen, few haem groups are bound to oxygen so haemoglobin doesn't carry too much oxygen

  
• at high partial pressure of oxygen, more haem groups are bound to oxygen, making it easier for haemoglobin to attach to oxygen

  
• • when co2 increases, rate of respiration increases
  • co2 dissolves in blood to form carbonic acid
  • change in blood pH affects haemoglobin
• haemoglobin becomes saturated at very pO2, as all the haem groups become bound

  
• what is the reversible reaction between haemoglobin and oxygen?

  Hb + 4O2 <--> Hb(O2)4

  haemoglobin + oxygen <--> oxyhaemoglobin
• the haemoglobin becomes saturated at very high pO2, as all the haem groups become bound