Download Reading guide - Chemistry Courses: About

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 to/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 oxygen bonding curve. Label the axes. What is Y? What is K?
5. Because hemoglobin oxygen binding is cooperative, the binding curve looks different. Draw
the hemoglobin oxygen binding curve, with a K of about 26 torr.
6. How does hemoglobin’s binding curve match its physiological role?
7. What is meant by “tense” and “relaxed’ states of a protein?
8. Start with the binding of one oxygen molecule to one hemoglobin subunit to describe the
structural basis of oxygen binding cooperativity.
9. What is an allosteric protein? Is myoglobin allosteric? Is hemoglobin allosteric?
10. 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?
Pratt and Cornely, Chapter 5.2-5.3
1. What are three types of cytoskeletal fibrous proteins?
2. Describe the structure of G-actin.
3. Describe F-actin. Explain how it has a (+) end and a (-) end.
4. How do some cells use actin to move? Explain, chemically, how this is an energy utilizing
process.
5. How are microtubules structurally similar to microfilaments, and how are they different?
6. Why are there drugs that target microtubules? How do colchicine and taxol work in opposite
ways to produce the same effects?
7. How are intermediate filaments structurally different from microfilaments and microtubules?
How are they functionally different?
8. What is a coiled-coil? Describe its intermolecular forces on an atomic level.
9. Describe keratin’s structure. How is it crosslinked? Where is it found in living things?
10. Is collagen more similar structurally to keratin or actin?
11. What is the most common amino acid sequence repetition observed in collagen? What
vitamin is essential for collagen formation, and why?
12. Why is Gly essential for collagen quaternary structure?
13. How are collagen molecules crosslinked?
14. Describe the structure of myosin. Where is its ATP binding pocket?
15 Draw the myosin-actin reaction cycle. What is its physiological function?
16. Describe the structure of kinesin. Where is its ATP binding pocket?
17. Draw the kinesis reaction cycle. What is its physiological function?
18. Kinesin is highly processive, but myosin is not. Explain why the different structures dictate
this. Explain why the physiological purposes matches the processive/non-processive
mechanisms.