Cytoskieleton Homework

Instructions              

Answer the following questions based on the Cytoskeleton lecture and on Zoom Disc. Refer to the textbook chapter to help you.

1. What is the structure and function of microtubules?

2. What types of bonds might be responsible for holding the tubulin dimers together in the filament?

3. Why must the interactions between microtubule protofilaments be non-covalent?

4. How might the property of dynamic instability influence the cell?

5. What happens to the tubulin dimers following depolymerization?

6. What is the role of energy in this microtubule process?

7. Why would the conversion from GTP-tubulin to GDP-tubulin result in a change in the organization of protofilaments?

8. Why is Dynamic Stability important for microtubules in a cell?

9. Why do centrioles reproduce during S phase? And where would the – and + ends be located?

10. What is the structure and function of intermediate filaments?

11. What is the function of actin?

12. Why is treadmilling important for actin filaments in a cell?

13. What is the difference between dynamic instability and treadmilling? How does this relate to structure/function relationships?

14. Why is energy needed for microtubules and actin filaments but not for intermediate filaments?

Cytoskieleton Homework Answer

1. What is the structure and function of microtubules?

• Microtubules are hollow and relatively rigid tubular structures that are assembled from the protein tubulin. They function primarily in the support of the cell, and transport of its organelles.

2. What types of bonds might be responsible for holding the tubulin dimers together in the filament?

• Tubulin globular proteins are tightly bound together by noncovalent bonds.