Which of these statements about the Oxygen Haemoglobin Dissociation Curve are correct?
The dissociation curve represents the saturation of haemoglobin with oxygen at any given partial pressure of oxygen.
Factors like pH and CO2 can cause the curve to shift to the left or to the right (see previous slide) increasing and decreasing the affinity of haemoglobin for oxygen.
If the curve shifts to the left, i.e. the affinity increases, then more oxygen is bound to haemoglobin at a given partial pressure.
If the curve shifts to the right, less oxygen is bound to haemoglobin at any given pressure i.e. more oxygen becomes available to the tissues.
This effect is greater in the middle of the curve since the curve is steepest there and shifting it causes bigger changes than e.g. at the higher end of partial pressures.