RG Haemoglobin

• What is oxygen carried round the body by?


  haemoglobin
• What is Hb?


  Haemoglobin
• What is the shortened version of haemoglobin?

  Hb
• What do red blood cells contain?

  Hb
• What is haemoglobin?


  A large protein with a quaternary structure(it is made up of 4 polypeptide chains)
• What does each polypeptide chain have?

  A haem group- which contains an iron ion and gives haemoglobin its red colour
• What does haemoglobin have?

  A high affinity for oxygen- each molecule can carry 4 oxygen molecules
• How many oxygen molecules can each haemoglobin molecule carry?

  4
• What does oxygen do in the LUNGS?

  Binds to haemoglobin in red blood cells to form oxyhaemoglobin
• What reaction happens in the lungs?

  oxygen joins to haemoglobin in red blood cells to form oxyhaemoglobin - this is a REVERSIBLE REACTION

  • Hb + 4O2  ⇌ HbO8
• What does haemoglobin saturation depend on?

  the partial pressure of oxygen
• What is the partial pressure of oxygen (pO2)?

  pO2

  • a measure of oxygen concentration
  • The greater the concentration of dissolved oxygen in cells, the higher the partial pressure
• What is the partial pressure of CO2?

  A measure of the conc of CO2 in a cell
• What does Hb's AFFINITY FOR OXYGEN vary depending on?

  the partial pressure of oxygen
• What happens where there is a high pO2?

  Oxygen loads onto haemoglobin to form oxyhaemoglobin
• What happens when there is a lower pO2?

  Oxygen unloads its oxygen
• define high affinity?

  haemoglobins with this for oxygen take up oxygen more easily , but release it less easily
• Define low affinity?

  Haemoglobins with this take up oxygen less easily, but release it more easily
• Define Positive Cooperativity?


  Binding of the first molecule makes binding of the second easier and so on, so the gradient of the curve steepens
• Define partial pressure?

  The amount of a gas that is present in a mixture of gases is measured by the pressure it contributes to the total pressure of the gas mixture