TJ guide 2

Question 1

T or F: microtubules in mitosis are both shorter and more dynamic than those in interphase

Answer 1

True

Question 2

What two categories of proteins are microtubules largely dependent on during mitosis?

Answer 2

Catastrophins, and microtubule accessory proteins

Question 3

Describe the microtubule involvement in prophase?

Answer 3

1. Centrosome segregation

2. Interpolar Microtubules stabilized by motor proteins and MAPS

Question 4

Describe microtubule involvement in prometaphase

Answer 4

None

Question 5

Describe microtubule involvment in metaphase

Answer 5

1. Microtubules attach at kinetochore pulling proteins to metaphase plate

Question 6

Describe microtubule involvement in anaphase

Answer 6

1. contractile ring starts to form
   Anaphase A
   -Poleward movement of chromosomes from kinetochore microtubule shortening (dependent of ATP-dependent catastrophin to remove tubulin)

Anaphase B

• Spindle poles pushed apart by sliding of interpolar microtubules (kinesin dependent)
• Astral microtubules pull the spindle poles to the periphery (dyenin dependent)

Question 7

What are vinblastin, vincristine, and taxol examples of?

Answer 7

Anti-cancer drugs b/c they inhibit mitosis and cell replication by preventing mitotic spindle formation

Question 8

How do vinblastin and vincristine work?

Answer 8

they BLOCK assembly causing disassembly

Question 9

How does Taxol work?

Answer 9

Stabilizes microtubules, preventing disassembly

Question 10

What is colchincine used for?

Answer 10

Treatment of gout

Question 11

How does Cochincine work?

Answer 11

• Prevents movement of granulocytes to affected joints

- binds tubulin and blocks assembly