haemoglobin

• describe the structure of haemoglobin?

  • protein made of four polypeptide chains
  • each chain contains a haem group which contain and iron ion
  • each haem group can carry one oxygen molecule each so in total 4
  • when iron binds to oxygen it turns red
• why does the %saturation of haemolglobin for a foetus turn to the left?

  higher affinity for oxygen and it can inhale or exhale and its source of oxygen is from its mother
• what is cooperatve binding?

  when one oxygen binds, it changes the quaternary structure of haemoglobin making it easier for more oxygen to bind
• what happens at high pressure of oxygen ? (lungs)

  • usually a high pressure in the lungs
  • oxygen moves from the alveoli down the pressure gradient to the blood
  • high association of oxygen to haemoglobin + positive cooperativity
• at high partial pressure does oxygen associated for dissociate ?


  associate
• at low partial pressures does oxygen associate or dissociate?

  dissociate
• describe the shape of the oxyhaemoglobin dissociation curve?

  1. initially binding is slow
  2. steep gradient due to positive cooperativity
  3. at the top , when most oxygen has binded, its harder for oxygen to find a binding site on iron so never 100% saturated

  
• what changes in the curve at low concentration of CO2 ?

  left
• what changes to the curve when there's a high concentration of Co2

  right
• what happens when there's a low concentration of CO2?

  • higher saturation of oxygen
  • higher affinity of oxygen
• what happens when there is a high concentration of co2?

  • lower affinity of oxygen
  • alot of co2 makes the blood acidic and lowers ph
  • Co2 reacts with water releasing H+ ions
  • changes the shape of haemoglobin
• what are 2 adaptations of haemoglobin?

  • can carry 4 oxygen molecules at the same time
  • positive coperativity