Question

What happens to microtubules at high concentrations (>2mM)?

1) They depolymerize
2) They polymerize
3) They remain unchanged
4) They become more dynamic

Answer 1

At concentrations above 2mM, microtubules polymerize, which involves the addition of α-tubulin and β-tubulin dimers at the plus end of the microtubule, playing key roles in cellular structure and function.

Step-by-step explanation:

At high concentrations, generally greater than 2mM, microtubules tend to polymerize rather than depolymerize. This polymerization occurs as α-tubulin and β-tubulin dimers add to the growing plus end of a microtubule, which is facilitated by the hydrolysis of GTP. As a component of the cytoskeleton, microtubules have dynamic properties allowing them to rapidly assemble and disassemble, which is critical for various cellular functions such as maintaining cell shape, vesicle transport, and chromosome separation during cell division.