What is the function of the spindle fibers? Which kind of cell contains centrioles and aster rays? How does cytokinesis differ in a plant and an animal cell? Which phase of the cell cycle is the longest?What are the two primary methods that can be used to determine a protein’s structure? What are the strengths and limitations of each method?
13. Describe the geometric features of the common secondary structure, the ? helix. Why is this structure especially common? What are the weak bonds that stabilize the ? helix?
14. Describe the geometric features of the common secondary structure, the ? sheet. Why is this structure especially common? What are the weak bonds that stabilize the ? sheet?
15. Describe in detail the helix-turn-helix structural motif and find specific roles or examples in which it has a main role.
16. Describe in detail the Zinc fingers structural motif and find specific roles or examples in which it has a main role.
17. How does a single-stranded DNA-binding protein ensure specificity for single-stranded DNA as opposed to double-stranded DNA? What do you think the purpose of this protein might be, for example, during DNA replication?
18. How does denaturation affect a proteins primary, secondary, tertiary, and quaternary structures?
19. DNA repair proteins, such as DNA glycosylase, recognize and remove damaged nucleotides. Based on what you know about protein-DNA interactions, suggest how these repair enzymes recognize mismatches or damaged bases in double-helix DNA, and suggest what specific contacts are made between the DNA repair protein and the mismatched (or damaged) base.