If every organelle were eliminated from a cell, the plasma membrane and cytoplasm would not be the only components left. There would still be organic molecules and ions present in the cytoplasm along with a network of protein fibers that assist in maintaining the shape of the cell. These fibers gain certain organelles in particular positions and allow vesicles and cytoplasm to move in the cell and let unicellular organisms to move freely. The network of protein fibers is called the cytoskeleton.
There are Three Kinds of Fibers that are Present in the Cytoskeleton Namely are -
Microfilaments consist of two intertwined strands of a globular protein known as actin. Therefore, they are also called actin filaments. They are the polymers of the protein actin and are the smallest filaments of the cytoskeleton. They perform an important role in cell movements, cell division, and muscle contraction.
A fluid that fills up the cells is referred to as the Cytoplasm. It consists of the cytosol filled with filaments, ions, proteins, and macromolecules structures and macromolecular structures along with other organelles that are suspended in the cytosol. The cytoplasm present in the eukaryotic cell mixes with the cell contents except for the nucleus. But this doesn’t happen in prokaryotic cells, as they do not have a defined nuclear membrane, the cytoplasm that possesses the genetic material of the cell. The cells, in comparison to the eukaryotes, are smaller and have an uncomplicated arrangement of the cytoplasm.
Microfilaments are the leanest filaments of the cytoskeleton present in the cytoplasm of eukaryotic cells that are of the diameter of about 5 to 8 nanometers. The polymers of these filaments are easy to use and at the same time are very strong and resist buckling and crushing while providing support to the cell.
Microfilaments are flexible components and play a vital role in building cytokinesis and the shape of a cell. The flexible arrangement of filaments framework enables it to help in the cell movement. The filaments have a vital role in contracting molecular motors driven by the actomyosin. In such procedures, the lean filaments become expanding platforms for the pulling action of myosins. It occurs mainly during pseudopod development and contraction.
Microfilaments provide shape and rigidity to the cell. They can dismantle and rebuild fast which enables a cell to change its shape and move. The white blood cells use this ability to a good extent and could reach the site of infection and submerge the pathogens.
Microfilaments are found at the cell periphery where they move from the plasma membrane to the microvilli. In this location, they are present in bundles that together form a three-dimensional intracellular meshwork. For example, they can be found in the pericanalicular zone where they build pericanalicular web/meshwork.