Question

Dynamic instability of growing microtubules results:

a. when the polarity of the microtubules is reversed
b. because beta-tubulin is much larger than alpha-tubulin
c. because of tubulin's ability to hydrolyze GTP to GDP
d. because longer protofilaments are less stable
e. when the microtubule is no longer useful to the cell

Answer 1

Dynamic instability of microtubules stems from tubulin's ability to hydrolyze GTP to GDP, affecting the stability of the growing microtubule structure.

Step-by-step explanation:

The dynamic instability of growing microtubules results from tubulin's ability to hydrolyze GTP to GDP. Microtubules are cytoskeletal structures composed of alpha-tubulin and beta-tubulin subunits. These structures are essential for various cellular processes, including maintaining the cell's shape, allowing the movement of organelles, and assisting with chromosome separation during cell division. Their dynamic nature is due to the GTP hydrolysis on the beta-tubulin subunits.

Once GTP is hydrolyzed to GDP, this can result in a less stable attachment of the subunit to the microtubule, leading to disassembly if the cap of GTP-bound tubulins at the growing plus end is lost, which is the foundation of the phenomenon of dynamic instability.