Which of the following observations helps to explain the conformational changes that occur in hemoglobin upon binding to oxygen?
A) The four heme groups are positioned close to the surface of the molecule.
B) An αβ dimer rotates and slides with respect to the other dimer upon binding oxygen.
C) Neither the heme nor the iron ion in the deoxy conformation is in a planar conformation.
D) All of the above
E) B and C

Question

Quizplus · Accepted Answer

The observation that the αβ dimer slides and rotates with respect to the other dimer upon binding oxygen explains the overall conformational change in hemoglobin. The observation that neither the heme nor the iron ion in the deoxy conformation is in a planar conformation helps to explain the specific changes that occur within the heme groups upon binding oxygen. The fact that the four heme groups are positioned close to the surface of the molecule is not directly related to the conformational changes that occur upon binding oxygen.

Which of the Following Observations Helps to Explain the Conformational