Haemoglobin Flashcards
Where is haemoglobin found?
In red blood cells
What is the role of haemoglobin?
To carry oxygen around the body
What protein structure does haemoglobin have?
Quaternary
How many polypeptide chains make up haemoglobin?
4
What does each chain have?
A haem group containing an iron ion
How many oxygen molecules can haemoglobin carry?
4
What does haemoglobin become when oxygen binds to it?
Oxyhaemoglobin
What is association/loading?
When an oxygen molecule joins to the haemoglobin
What is dissociation/unloading?
When an oxygen molecule leaves oxyhaemoglobin
What does having an affinity for oxygen mean?
The tendency a molecule has to bind with oxygen
What affects haemoglobin’s affinity for oxygen?
Partial pressure of oxygen
The greater the concentration of dissolved oxygen in cells…
the higher the partial pressure
Does an increase or decrease in partial pressure cause an increase in haemoglobins affinity for oxygen?
Increase
When does oxygen load onto haemoglobin?
When theres a high partial pressure
When does oxyhaemoglobin unload oxygen?
When theres a lower partial pressure
Do alveoli have a high or low partial pressure? What does this mean happens to the oxygen?
High
It loads onto haemoglobin
Does respiring tissue have a high or low partial pressure?
Low
Does oxygen load or unload at respiring tissues?
Unload
An increase in respiration in the tissue of a mammal affects the oxygen dissociation curve of haemoglobin. Describe and explain how. (2 marks)
- Respiration produces CO2
- The curve will shift to the right (Bohr shift) so there will be more unloading
Describe how the haemoglobin in one organisms may have a different chemical structure from the haemoglobin in another organism (1 mark)
Different number of polypeptide chains
