Chapter 17, Problem 20Q

Summary Introduction

To explain: The difference between the electron micrographs of the rapid growing population of microtubules and catastrophic shrinking microtubules.

Concept introduction:

The microtubules are hollow and cylindrical in structure. They are approximately 25 nm in diameter, present in all eukaryotic cells and play crucial roles in the determination of a cell shape and also in cellular motility. It is composed with α β-tubulin having two subunits such as α-tubulin and β-tubulin. The β-tubulin subunits are exposed at the plus ends and α-tubulin subunits are exposed at their minus ends. The dynamic instability is based on the switching between phases of relatively slow growing and rapid shortening at the ends of individual microtubules. It is a result of the hydrolysis of GTP-bound to β-tubulin shortly after assembly.