| What is a haemoglobin | - a large protein with a quaternary structure
- it's made up of 4 polypeptide chains
- each chain has a haem group which contains iron
- each molecule of haemoglobin can carry 4 oxygen molecules |
| What is the role of haemoglobin | To carry oxygen around the body. |
| What is oxyhemoglobin | When oxygen joins the iron in the haemoglobin |
| What does association or loading mean | When an oxygen molecule joins to haemoglobin |
| What does dissociation or unloading mean | When oxygen leaves oxyhemoglobin |
| What is the equation for the association and dissociation of oxyhemoglobin | Hb + 4O2 ⇌ HbO8 |
| Define affinity for xygen | The tendency a molecule has to bind with oxygen |
| What is the partial pressure of oxygen | pO2 - the measure of oxygen concentration |
| Where does oxygen load onto haemoglobin to form oxyhemoglobin | Where theres a high pO2 |
| Where is oxygen unloaded | Where there's a low pO2 |
| What happens when carbon dioxide and water react | With the help of carbonic anhydrase, they form carbonic acid which dissociates into HCO3- and H+ ions |
| How is haemoglobinic acid formed | When H+ ions combine with haemoglobin |
| What shape is the dissociation curve | S shaped |
| Why is the dissociation curve shaped the way it is | - when haemoglobin combines with the first O2 molecule, its shape alters to make it easier for other molecules to join
- but as haemoglobin starts to become saturated, it gets harder for more oxygen molecules to join |
| Explain the Bohr effect | When carbon dioxide levels increase, the dissociation curve shifts to the right, showing more oxygen is released from the blood |
| Explain chloride shift | To compensate fore the loss of HCO3- ions from the red blood cells, chloride ions diffuse into the red blood cells. |
