Haemoglobin Flashcards
What is haemoglobin?
A protein with a quaternary structure
What is the role of haemoglobin ?
Transport and unloading of oxygen in relation to the oxyhaemoglobin dissociation curve. The cooperative nature of oxygen binding to show that the change in shape of haemoglobin caused by binding of the first oxygens makes the binding of further oxygens easier
What is associate ?
When oxygen binds to haemoglobin
What is dissociate ?
When oxygen leaves oxyhaemoglobin
What is affinity ?
How readily oxygen associates to haemoglobin
What is partial pressure ?
The pressure created by a gas in a specific space
What is the Bohr effect ?
The effect of carbon dioxide on the affinity of haemoglobin e.g the more carbon dioxide the lower the affinity of haemoglobin for oxygen
What is the cooperative nature of oxygen binding ?
First molecule of oxygen to bind causes a change in shape of haemoglobin this uncovers other binding sites making the binding of further oxygen is easier
How does loading and unloading work in high partial pressures of oxygen and low partial pressure of oxygen?
At high partial pressures of oxygen example in the lungs oxygen is loaded as most finding sites are attached to oxygen. The affinity of haemoglobin for oxygen here is high. A low partial pressure of oxygen example in respiring tissues oxygen is unloaded due to the high concentration of carbon dioxide in these tissues that affinity of haemoglobin for oxygen is lower.
What does the oxygen dissociation curve show?
How much oxygen is being carried by haemoglobin at any partial pressure of oxygen? The shape of oxygen dissociation curve is as shaped due to the cooperative finding of haemoglobin. The steep gradient in the middle of the curve is the small change in partial pressure this leads to a large change in the amount of oxygen carried by haemoglobin the steepest point of the curve corresponds to the partial pressure of tissues.
Why are there different haemoglobin molecules?
The shape of haemoglobin molecule varies between different animals and this causes the haemoglobin to have different affinity for oxygen. The different shapes are due to different gene coding for different amino acid sequences.
What is the effect of carbon dioxide and the Bohr shift?
Carbon dioxide causes the curve to shift to the right the haemoglobin affinity for oxygen reduces oxygen dissociate from the haemoglobin more readily more oxygen is unloaded to tissues for aerobic respiration
