Download Reading Guide: Pratt and Cornely, Chapter 5.1 1. Compare and

Reading Guide: Pratt and Cornely, Chapter 5.1
1. Compare and contrast the roles of myoglobin and hemoglobin.
2. Describe the major structural features of myoglobin and how they are similar/different than
hemoglobin.
3. Draw a simple schematic of the ligands that bind to the iron ion found in myoglobin. What
does His F8 do, and why is it called that? What additional amino acid residue binds to molecular
oxygen?
4. Draw a myoglobin hydrogen bonding curve. Label the axes. What is Y? What is K?
5. If the dissociation constant of myoglobin is 2.8 torr, what is the fractional saturation of
myoglobin at an oxugen partial pressure of 7.4 torr?
6. Because hemoglobin oxygen binding is cooperative, the binding curve looks different. Draw
the hemoglobin oxygen binding curve, with a K of about 26 torr.
7. How does hemoglobin’s binding curve match its physiological role?
8. What is meant by “tense” and “relaxed’ states of a protein?
9. Start with the binding of one oxygen molecule to one hemoglobin subunit to describe the
structural basis of oxygen binding cooperativity.
10. What is an allosteric protein? Is myoglobin allosteric? Is hemolglobin allosteric?
11. What is the hemoglobin structural difference that leads to sickle cell anemia?
11. What is the Bohr effect, and what role does it play in the physiology of oxygen binding by
hemoglobin?
12. What is BPG, and what role does it play in the physiology of oxygen binding by
hemoglobin?