Myoglobin and haemoglobin

The fractional saturation of myoglobin and haemoglobin molecules varies with the partial pressure of oxygen. The different shapes of the curves account for the different biological functions of the two proteins.

The saturation curves are given by

Where sMb is the saturation curve for myoglobin, sHb is the saturation curve for haemoglobin, and p (Torr) is the partial pressure of oxygen.

To graph a pair of saturation curves enter the parameters (i.e., K's) and hit New Plot. Up to 3 plots pairs can be displayed at one time. The Clear button will remove all plots. To see the parameters for each plot hit the Legend on/off button. The Redraw button will refresh the graph. This is useful when the function domain (i.e., p ) has been changed. To see the value of each plot at a given point, move your cursor to the desired location then click and hold.