Oxygen - haemoglobin dissociation: modifiers and importance to oxygen transport

2021-05-16 11:30 PM

pH drops more than normal value from 7.4 to 7.2; The Oxy-haemoglobin dissociation graph shifts to the right by about 15% on average. In contrast, the increase in pH from the normal 7.4 to 7.6 curve also shifts to the left by a similar amount.

Oxygen-haemoglobin dissociation graph in Figures 41-8 and 41-9 under normal blood and body conditions. However, some factors can shift the dissociation graph in a different direction as shown in the figure. This figure shows that when the blood becomes slightly acidic, the pH drops more than its normal value from 7.4 to 7.2; The Oxy-haemoglobin dissociation graph shifts to the right by about 15% on average. In contrast, the increase in pH from the normal 7.4 to 7.6 curve also shifts to the left by a similar amount. In addition to pH change, there are several other factors known to shift the graph.

Figure. Oxy-haemoglobin dissociation graph

 

Figure. Effect of blood PO2 on the amount of oxygen bound to haemoglobin in each 100 ml of blood

Figure. The shift of the oxy-hemoglobin dissociation curve to the right is due to an increase in hydrogen ion concentration (decrease in pH). BPG, 2,3-biphosphoglycerate

Three of these, all plotting to the right, are (1) an increase in CO2 concentration, (2) an increase in blood temperature, and (3) an increase of 2,3- biphosphoglycerate (BPG)- a compound phosphate is important for metabolism, occurring in the blood in varying concentrations under different metabolic conditions.