Question

The end of a growing microtubule is rich in which type of tubulin molecule?

A. GTP-associated tubulin molecules
B. GDP-associated tubulin molecules
C. ATP-bound tubulin molecules
D. ADP-bound tubulin molecules

Answer 1

The end of a growing microtubule is rich in GTP-associated tubulin molecules, which is crucial for the dynamic assembly and disassembly of microtubules in cellular processes.

Option a. GTP-associated tubulin molecules is correct answer.

Step-by-step explanation:

The end of a growing microtubule is rich in GTP-associated tubulin molecules. Microtubules are composed of α-tubulin and β-tubulin dimers, and as they assemble, GTP-bound α/β-tubulin dimers add to the growing plus end of the microtubule. Once GTP is hydrolyzed to GDP, the stability of the microtubule decreases. This cycle of assembly and disassembly is crucial for cellular processes such as mitosis, where microtubules help in the separation and movement of chromatids.

This knowledge aids in understanding the dynamic nature of the cytoskeleton and its critical roles in intracellular transport and cell division.

The correct option for GTP-associated tubulin molecules at the growing end of a microtubule is option A.