Question

List two things you could do that would shift the dynamic equiLiBrium of an in vitro preparation of tubulin and microtubules toward the formation of microtubules. List two treatments that would shift the equiLiBrium in the opposite direction.

Answer 1

To promote microtubule formation, increase tubulin or GTP concentrations; to inhibit it, add drugs like vincristine or colchicine, or lower the temperature. Chemotherapy drugs target the mitotic spindle, affecting cell division.

Step-by-step explanation:

To shift the dynamic equilibrium of an in vitro preparation of tubulin and microtubules toward the formation of microtubules, one could increase the concentration of tubulin monomers in the solution or increase the concentration of GTP. Increasing tubulin concentration provides more substrate for microtubule assembly, while GTP is necessary for the polymerization process.

To shift the equilibrium in the opposite direction, treatments could include adding drugs like vincristine or colchicine, which bind to tubulin and interfere with its assembly into microtubules, or one could lower the temperature of the solution as microtubule polymerization is temperature-sensitive. These treatments would hinder the assembly of microtubules, thereby promoting disassembly.

Chemotherapy drugs like vincristine and colchicine specifically target the mitotic spindle, a structure composed of microtubules, during cell division. By binding to tubulin and preventing its polymerization, these drugs disrupt the proper segregation of chromosomes to daughter cells, which can lead to cell death or prevent cell division.