Question

You are curious about the dynamic instability of microtubules and decide to join a lab that works on microtubule polymerization. The people in the lab help you grow some microtubules using conditions that allow you to watch individual microtubules under a microscope. You can see the microtubules growing and shrinking, as you expect. The professor who runs the lab gets in a new piece of equipment, a laser beam that is very fine and can be used to sever microtubules. She is very excited and wants to sever growing microtubules at their middle, using the laser beam.

a. Do you predict that the newly exposed microtubule plus ends will grow or shrink? Explain your answer.
b. What do you expect would happen to the newly exposed plus ends if you were to grow the microtubules in the presence of an analog of GTP that cannot be hydrolyzed, and you then severed the microtubules in the middle with a laser beam?

Answer 1

Follows are the explanation to the given points:

Step-by-step explanation:

The polymerization of αβ-tubulin ligands costumes the microtubules. Among rising or reducing processes a microtubule may oscillate. Part of the carbon is a polar framework for two separate ends: a rapidly growing, most ending as well as a slow-growing less end.

In point a:

Severing a mitochondrial membrane throughout the media will create new "plus ends" or "minus ends." when mentioned in the question Then microtube is more prone to growth at most by adding GTP sub-units to some of the most open regions, where β-tubulin is activated. Even so, for some time GTP has also been hydrolyzed, keeping only one cap of the newly created, higher-end GTP-carrier subunits together with the remaining GDP-carrying cylindrical cap.

Consequently, a positive end is developed that consists of GDP subunits. Because the GDP sub-units become less strictly connected than that of the GTP sub-units, they eventually separate from one another. This allows a microtubule to be polymerized which causes the microtubule will shrink. But the newly exposed microtubule and sides will shrink if cut throughout the center.

In point b:

Well if the equivalent of GTP with such a microtubule is separated by laser from a non-hydrolyzable one, the newly exposed plus finish will include GTP carries. This GTP was NOT supplied with both the GDP kinase but would still expand the mitochondrial membrane. The unburned GTP plus microtubule will therefore continue to grow once it is cut in the center. The GTP equivalent is not hydrolyzable.