Answer to Question #198731 in Biochemistry for ace

Question

Under which of the following conditions is the R form of Hb favored?

a.At low O2 partial pressures, as in the lungs.

b.At high O2 partial pressures, as in muscles.

c.At low O2 partial pressures, as in muscles.

d.At high O2 partial pressures, as in the lungs.

e.The R form of Hb does not depend on the presence of O2

Answer 1

The R-state or oxygenated haemoglobin is favoured when the amount of oxygen available is higher because the first oxygen bonded to it gives more affinity towards adding more O₂ molecules (up to four can be bonded to Hb). Since the lungs have more oxygen compared to the muscle cells (due to the breathing) the equilibrium that helps the formation of R-state or oxygenated haemoglobin is impulsed at the respiratory system.

In conclusion, the correct answer for the question is

d. At high O2 partial pressures, as in the lungs.

Reference:

• Berg, J. M., Tymoczko, J. L., & Stryer, L. (2002). Biochemistry.