Question

What is the structure of the tube made of ?

1) Linear chains of tubulin dimers.
2) 13 parallel protofilaments formed by tubulin dimers.
3) 13 parallel microtubules made of tubulin dimers.
4) 13 parallel chains of protofilaments made of tubulin dimers.

Answer 1

Microtubules are small hollow tubes made up of polymerized dimers of α-tubulin and β-tubulin. The structure of the tube is formed by 13 parallel protofilaments composed of tubulin dimers.

Step-by-step explanation:

Microtubules are small hollow tubes that make up the cytoskeleton of cells. The walls of the microtubule are made of polymerized dimers of α-tubulin and β-tubulin, two globular proteins. The structure of the tube is formed by 13 parallel protofilaments composed of tubulin dimers. These protofilaments come together to create a hollow cylinder with a diameter of approximately 25 nm.