Cytoskeleton-Definition and Types

Introduction: 

Cells are the fundamental units   of all living organisms. In unicellular organisms, the entire body of the organism is made up of a single cell like prokaryotes, bacteria, and yeast. In multicellular organisms, the body is made up of many cells, in their cells form tissues, organs, and organ systems, and finally the organism like eukaryotes, plants, animals, and fungi.    

Explanation 

The cytoplasm is a jelly-like substance in which organelles of the cells are embedded. It helps the organelles to carry out various jobs in the cell. The cytoplasm is constantly moving through the cell in a stream-like motion.   

There are two main components:   

• Cytosol   
• Cytoskeleton 

Cytoskeleton 

The cytoskeleton is the network of fibers forming the prokaryotes and animal cells. The cytoskeleton maintains the shape and internal organization of the cell and provides mechanical support. These fibers contain a complex mesh of protein filaments and motor proteins that help in cell movement. 

Types of cytoskeletons  

Microtubules 

Microtubules are small, hollow, round tubes with a diameter of about 25 nanometers. They are composed of a protein, tubulin. 13 tubulins link to form a single tube. They radiate through the cytoplasm where they perform numerous functions. Microtubules help in transporting cellular materials as well as dividing chromosomes during cell division. 

Microfilaments 

Microfilaments are protein fibers like threads, in diameter 3-7 nm, made up of actin monomer. They are usually located in the circumference of the cells and especially in the muscle cells. They are involved in the cellular motion of the cells and consist of two interconnected threads of a circular protein called actin. They give the cell some hardness and shape. WBC uses this capacity to act on infections and surround pathogens. 

Intermediate filaments 

Intermediate filament types are found in animal cells. They are composed of the proteins having same structural and sequence properties. They have an average diameter of 10 nanometers, which is between that of 7 nm actin microfilaments  , and that of 25 nm microtubules. Intermediate filaments contribute to cellular structural elements and often play an important role in holding together tissues like skin. 

Flagella and Cilia 

Flagella is a long, hairy structure that arises from the plasma membrane and is used to move the whole cell. For example, sperm cells, euglena, etc. Cilla is a short, hairy structure that arises along the entire surface of the plasma membrane and is used to move entire cells. For example, paramecium, fallopian tube lined by cilia. 

Flagella and Cilia 

Flagella is a long, hairy structure that arises from the plasma membrane and is used to move the whole cell. For example, sperm cells, euglena, etc. Cilla is a short, hairy structure that arises along the entire surface of the plasma membrane and is used to move entire cells. For example, paramecium, fallopian tube lined by cilia. 

Functions of cytoskeletons

• It provides shape and support to the cell.  
• It keeps different organelles in the proper place.   
• It helps in the production of vacuoles.  
• It helps in signaling.  
• It supports intracellular movements like the migration of cell organelles, transportation of vesicles in and out of the cell, etc. 

Summary

• Cells are fundemental, and functional unit of all organisms.
• The cytoplasm is a jelly like substance in which organells of the cells are embedded. It helps the organells to carry out various jobs in the cells.
• The cytoskeleton is the network of fibers forming the prokaryotes and animal cells.
• Microtubules are small, hollow, round tubes with a diameter of about 25 nanometers. They are composed of a protein, tubulin. 13 tubulins link to form a single tube.
• Microfilaments are protein fibers like threads, in diameter3-7 nm, made up of actin monomer. They are usually located in the circumference of the cells and especially in the muscle cells .
• Intermediate filament types are found in animal cells. They are composed of the proteins having same structural and sequence properties.
• Flagella is a long, hairy structure that arises from the plasma membrane and is used to move the whole cell.