Haemoglobin Flashcards
Describe the structure of haemoglobin
It is a quarternary protein made of four polypeptides, globins.
A haem group is in the centre of each globin
What significant ion does haem contain?
Fe2+ which will be able to bind with oxygen.
Give examples of adaptations of haemoglobin for different environments
Llamas that live in high altitudes experience a lower partial press. of O, so haemoglobin should be adapted to take in as much as possible
Foetal haemoglobin can absorb O at lower conc., this is useful since mother’s blood has a lower conc. of O than the air outside
What is oxyhaemoglobin?
The complex formed when haemoglobin binds to oxygen
Oxygen dissociation curve
S shape
Low partial pressure of CO2: moves to left
Higher partial pressure of CO2: moves to right
What is the Bohr effect?
-A high partial press. of carbon dioxide leads to this
- More acidity = Lower pH
- This changes shape of oxyhaemoglobin, so it unloads more oxygen
- Useful for active muscle producing CO2, means
more respiration = more oxygen supply.
Describe how haemoglobin loads and unloads oxygen in the body
- Uptake of oxygen at a high pO2
- In lungs, haemoglobin has a higher affinity for oxygen
- Unloads at a low pO2
- Unloads at a high conc. if carbon dioxide
Explain the relationship between SA:Vol of mammals and dissociation curves of haemoglobin. (Heat from respiration helps mammals maintain body temp)
- Small mammal = High SA:Vol
- High SA:Vol = more heat loss
- Greater respiration rate
- Oxygen required for respiration
- Haemoglobin releases more oxygen
How is oxygen in a red blood cell is made available for respiration in active tissue?
- increased dissociation if haemoglobin
- Oxygen diffuses from red blood cells to tissues
How is efficient gas exchange ensures by the differences in dissociation curves for women and foetuses?
- Foetal dissociation curve is more to the left
- foetal haemoglobin has a higher affinity for oxygen
- loads oxygen from mothers blood
What is the advantage of the Bohr shift?
- Haemoglobin has a lower affinity for oxygen and unloads it more readily
- To muscles
- For rapid respiration