Question

What is likely to happen to microtubules in the cell if the concentration of tubulin subunits increases?

a. Microtubules will cycle faster between growing and shrinking phases.
b. The diameter of the microtubule cylinder will be larger.
c. Microtubules will tend to grow
d. There will be no change in microtubule behavior.
e. Microtubules will tend to shrink.

Answer 1

If the concentration of tubulin subunits increases in the cell, microtubules will tend to grow because higher concentrations of tubulin subunits promote the addition of these subunits to the growing ends of microtubules.

Step-by-step explanation:

When the concentration of tubulin subunits increases in the cell, microtubules will tend to grow. This is because microtubules are dynamic structures composed of α-tubulin and β-tubulin dimers that polymerize to form hollow cylinders, and their assembly is a balance of addition and loss of tubulin subunits. When the concentration of free tubulin subunits is high, it favors the addition of these subunits to the plus end (+end) of microtubules, promoting their growth. This process is essential for various cellular functions such as maintaining cell shape, assisting in vesicle transport, and facilitating chromosome segregation during cell division.