Question

The following data describe the binding of oxygen to human myo- globin at 37 °C. Po, (mm Hg) Yo, Po, (mm Hg) Yo, 0.5 8 0.161 0.277 0.434 0.535 0.605 0.697 0.754 0.821 0.885 12 20 From these data, estimate (a) P50 and (b) the fraction saturation of myoglobin at 30 mm Hg, the partial pressure of O2 in venous blood./

PLEASE, EXPLAIN. I am not sure on how to find the y equation based on the data and the plotted graph. I need step by step explanation. Thanks!

Answer 1

a)P50 is the standard partial pressure where haemoglobin is 50% saturated with O2. According to the Hill equation,

YO2 = (pO2)n / {(p50)n + (pO2) n }

Now for the part (b), n=1, due to myglobin

• So by the use of the formula, you can put the values of the partial pressures of O2 and the values of YO2 and then calculate the values of p50 for each partial pressure
• Then you can plot the values of the P50 against the YO2 values and find the saturation point of the myoglobin at the given partial pressure of O2

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