Chapter 17, Problem 1RTC

Summary Introduction

To Review:

The three components of the eukaryotic cytoskeletal filaments. Compare them in terms of the composition, function and structure.

Introduction:

The cytoskeleton is the interlinking protein filament, which is present in the cytoskeleton of the eukaryotic as well as prokaryotes. It helps in the maintenance of the cellular structure and locomotion.

Explanation of Solution

The eukaryotic cells have three main types of the cytoskeleton filaments. These are microfilaments, intermediate filaments and microtubules.

The microfilaments are also known as the actin filaments and present in the cytoplasm of the eukaryotic cells. They are mainly composed of the polymers of the G-actins. They are 7-9 nm in diameter. The microfilaments help in the movement of the membrane, organelleand the cytoplasm. It provide the structural support, they also help in muscular contraction and relaxation.

The intermediate filaments are the cytoskeleton structural components which are found in a twisted strand. They are composed of keratin, vimentins and other keratin like subunits. They are 8-12 nm in diameter. The main function of the intermediate filament is to provide mechanical support to the plasma membrane.

The microtubules are the hollow cylindrical filaments, which are made up of a and β-tubulins. They are 24 nm in diameter. The function of the microtubule is to provide shape and internal organization of the cells; it also helps in the division of the cell and movement.

Conclusion

There are three component of the cytoskeleton in the eukaryotic cells.

1. Microfilaments: mainly composed of G actin subunit and help in providing structural support and movement.
2. Intermediate filaments: mainly composed of keratin and vimetins, they provide mechanical strength.
3. Microtubules: mainly help in mobility and cell division. They are made up of a and β-tubulins.