Transport of oxygen

• What is an oxygen dissociation curve?

  Relationship between oxygen saturation and partial pressure of oxygen
• What is pO2?

  Partial pressure of oxygen
• Explaining the oxygen dissociation curve:

  • Shallow gradient initially
  • Binding of first oxygen molecule changes the shape of the haemoglobin
  • This makes it easier for more oxygen to bind
  • This is called positive cooperativity
  • After the third molecule has bound it’s harder for the fourth molecule to bind as most binding sites are occupied
  • The graph plateaus
• If CO2 concentration increases, what happens to the affinity of oxygen?

  Decreases