transporting CO2 + O2

• factors affecting dissociation:

  1. pH
  2. body temperature
  3. concentration of CO2
• Body temperature:

  • increasing body temp.
  • reduces haemoglobin affinity for O2
  • more O2 is delivered to warmed-up tissue
• pH:

  1. lowering of blood pH
  2. is caused by presence of H+ ions from lactic acid or carbonic acid
  3. reduces affinity of Hb for O2
  4. more O2 is delivered to acidic sites which are working harder

  
• concentration of CO2:

  1. the higher CO2 concentration in tissue
  2. the less the affinity of Hb for O2
  3. so the harder the tissue is working, the more O2 is released
• Bohr shift: graph shifts to the right, affinity decrases
• foetal haemoglobin: higher affinity is needed for oxygen in the placenta

  
• myoglobin: has a very high affinity for oxygen even at low partial pressures and they release oxygen when O2 levels are too low.