Hello Aspirant,

The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including bacteria and archaea.[1] It extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms.

In eukaryotes, it is composed of three main components -

1. Microfilaments

2. Intermediate filaments

3.Microtubules

These are all capable of rapid growth or disassembly dependent on the cell's requirements

Microfilaments

Microfilaments are fine, thread-like protein fibers, 3-6 nm in diameter. They are composed predominantly of a contractile protein called actin, which is the most abundant cellular protein. Microfilaments' association with the protein myosin is responsible for muscle contraction. Microfilaments can also carry out cellular movements including gliding, contraction, and cytokinesis.

Microtubules

Microtubules are cylindrical tubes, 20-25 nm in diameter. They are composed of subunits of the protein tubulin--these subunits are termed alpha and beta. Microtubules act as a scaffold to determine cell shape, and provide a set of "tracks" for cell organelles and vesicles to move on. Microtubules also form the spindle fibers for separating chromosomes during mitosis. When arranged in geometric patterns inside flagella and cilia, they are used for locomotion.

Intermediate Filaments

Intermediate filaments are about 10 nm diameter and provide tensile strength for the cell.

HOPE THIS WILL HELP YOU

GOOD LUCK!

Hello Student,

Different cytoskeletal structures are as follows :

Microtubules :

• Made up of alpha and beta tubulin proteins
• Constitues flagella, cilia , spindles
• Colchicine arrests cell division at metaphase stage by disrupting spindle fibres
• They cannot contract but assemble and dissemble
• Each of these microtubules is made up of 13 Microfilaments
• These are 20-25 nm in diameter.

Microfilaments :

• Made up of a single monomer called actin
• They are solid Linear cytoskeletal structure and are able to contract
• Help in cytoplasmic streaming and cell motility
• These are 3-6 nm in diameter

Intermediate filaments :

• Present in cellular junctions
• They form a basket around nucleus
• These are polymerized keratin structures
• Diameter is about 10 nm

Hope this helps. I have provided the important points regarding cytoskeletal structures.