Question

Calculate the oxygen partial pressure, in torr, at which 97% of myoglobin molecules exist in the oxygen-bound state. Assume p50(Mb).

Answer 1

Answer:

Partial pressure of oxygen = 90.53 torr

Explanation:

Using the formula; YO₂ = (pO₂)ⁿ / (pO₂)ⁿ + (p₅₀)ⁿ

where Y is the fraction of oxygenated myoglobin, pO₂ is the partial pressure of O₂, expressed in torr (760 torr = 1 atmosphere) and p₅₀ is the partial pressure of O₂ required to bind 50% of the myoglobin molecules, n is Hill's constant which describes the degree of cooperativity among interacting ligand sites or subunits

p₅₀ = 2.8 torr

n = 1 for myoglobin calculations since it only contains one heme group

YO₂ = 97% or 0.97

pO₂ = x

substituting the values

0.97 = x (2.8 + x)

x - 0.97x = 2.716

0.03x = 2.716

x = 2.716 / 0.03

x = 90.53 torr