Heamoglobin Flashcards
1
Q
Describe how haemoglobin normally loads oxygen in the lungs and unloads it in a tissue cell.
A
- Oxygen combines forming oxyhemoglobin
- Each haemoglobin carries 4 molecules of oxygen
- High partial pressure of oxygen in lungs
4.Oxygen Saturation around 95-100% in haemoglobin - Unloads at low partial pressures of oxygen
- High co2 concentration increases dissociation
- Allowing more oxygen to be unloaded at tissues
2
Q
Explain how oxygen in a red blood cell is made available for respiration in active tissue. 4points
A
- High partial pressures of co2 due to respiration
- Increased dissociation of oxygen from haemoglobin
- Low partial pressures of oxygen in tissue
- Oxygen moves form red blood cell to tissues
3
Q
The oxygen dissociation curve of a foetus is to the left of its mother. Explain the advantage of this for the foetus. 3points
A
- Low partial pressure of oxygen in lungs
- Haemoglobin have higher affinity for oxygen at lower partial pressures of o2
- Oxygen moves from mother to feotus
4
Q
Explain how oxygen is loaded, transported, and unloaded in the blood. 5points
A
- Haemoglobin can carry 4 molecules of oxygen at a time
- In red blood cells
3 There is high partial pressures of oxygen in the lungs so more oxygen is loaded as haemoglobin has a higher affinity - Oxygen is unloaded at low partial pressures of oxygen
- High partial pressures of co2 also causes unloading of oxygen
5
Q
Binding of one molecule of oxygen makes it easier for a second oxygen to bind. Explain why. 2points
A
- First oxygen molecule binds stimulating a change in tertiary structure
- Exposing the other binding sites
6
Q
Describe and explain the effect of increasing co2 concentration on the dissociation of oxyhemoglobin. 2points
A
- High partial pressures of co2 causes the oxygen dissociation curve to shift right
- Haemoglobin have lower affinity for oxygen due to the increase in acidic conditions increasing dissociation of oxyhemoglobin
