Haemoglobin and oxygen dissociation curve:

Cards (10)

What is an erythrocyte?
A red blood cell
What are the adaptations of erythrocytes?
biconcave, loads of haemoglobin and have no organelles.
What is haemoglobin?
Conjugated protein made of 4 polypeptide chains.
Each chain is bound to a group called haem which contains the iron ion.
What is haemoglobin called when all haem groups are binded to oxygen?
oxyhaemoglobin- and this reaction is reversible.
What is the oxygen dissociation curve used for?
It is used to measure the amount of oxygen that combines with haemoglobin and different partial pressures.
What shape is the dissociation curve of oxygen?
sigmoid - s shaped
What is affinity?
How strong the oxygen is bound to the haemoglobin
At low partial pressures for oxygen what affinity does haemoglobin have for oxygen?
Low.
What is positive cooperativity?
Once one molecule of oxygen is bound, affinity increases as only a small increase in partial pressure is needed.
What causes oxygen to dissociate for haemoglobin?
When aerobic respiration is occurring haemoglobin moves to active areas of tissue which causes partial pressure of oxygen to be low so one oxygen unbinds. This changes the quaternary structure of haemoglobin and decreases its affinity.