Question

What is likely to happen to microtubules in the cell if the tubulin subunits are loaded with a non-hydrolyzable analog of GTP?

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

Answer 1

If tubulin subunits are loaded with a non-hydrolyzable analog of GTP, microtubules will tend to shrink.

Step-by-step explanation:

When tubulin subunits are loaded with a non-hydrolyzable analog of GTP, the microtubules will tend to shrink. This is because normally, during microtubule assembly and disassembly, GTP is hydrolyzed to GDP and this process helps to regulate the growth and stability of microtubules. However, when tubulin subunits are loaded with a non-hydrolyzable analog of GTP, the hydrolysis cannot occur, leading to destabilization and shrinkage of the microtubules.