What are microtubules?

Answer

Microtubules are hollow tubes about 20 to 25 nanometers in diameter that function in cell movement and provide structure within the cell. These tubes consist of subunits, called heterodimers, composed of two closely related molecules, called alpha-tubulin and beta-tubulin, that are structurally bound to one another. Each microtubule unit consists of a wall made up of 13 subunits of alpha- and beta-tubulin heterodimers, which are called protofilaments.

On one side of the microtubule, the alpha-tubulin is exposed. This is the plus side, meaning that this is the site where the microtubule grows. The other end contains the exposed beta-tubulin; this is the minus end that gets shortened. In the cell, microtubules constantly get broken down and put back together.

Substances inside the cell are constantly moving around. Additionally, sometimes even the cells themselves have to move around in their environment. Microtubules move organelles around in the cell by providing a route or tracks along which organelles move. During cell division, the chromosomes are pulled to opposite ends of the dividing cell by microtubules. Some cells move around using cilia, which are hair-like projections, and flagella, structures resembling small whips. Microtubules make up both the cilia and the flagella.

Microtubules are part of a system of several components working together called the cytoskeleton. Other components of the cytoskeleton are the microfilaments and the intermediate filaments.

Q&A Related to "What are microtubules?"
Microtubules are a sort of transport system within an organism. They consist of straight hollow cylinders responsible for providing tracks for the movement of cell organelles and
http://www.ask.com/web-answers/Science/Biology/wha...
Microtubules, being part of the cytoskeleton... help a cell maintain its
http://wiki.answers.com/Q/What+is+the+shape+of+a+m...
Any of the minute tubules in eukaryotic cytoplasm that are composed of the protein tubulin
http://www.chacha.com/question/what-is-a-microtubu...
Mitosis is the process that cells use to divide one parent cell into two genetically equivalent daughter cells. Microtubles are integral in this process by attaching to the center
http://www.ehow.com/info_8552402_main-function-mic...
1 Additional Answer
Ask.com Answer for: what are microtubules
Microtubules are cylidrical structures bundled into centrioles. They provide structural support for the cytoskeleton of the cell as well as connectivity between other organelles.
Explore this Topic
Spindle fibers are made up of microtubules. These clusters of microtubules are responsible for moving chromosomes during cell division. Spindle fibers are created ...
An important organelle in the division of animal cells is the centrosome. The centrosome is the microtubule generating and organizing center of the cell. Microtubules ...
A centriole is the part of a cell that helps to organize microtubules, and it is involved in mitosis. Centrioles are only present in animal cells. You can find ...
About -  Privacy -  Careers -  Ask Blog -  Mobile -  Help -  Feedback  -  Sitemap  © 2014 Ask.com