Question

State whether the following statements are true or false.
Actin is a globular protein that assembles as long as a beady structure consisting of two helical chains.

Answer 1

Actin is a family of multi-functional globular protein that makes the microfilaments. It is an essential part of the cytoskeletal structure and is found in all the eukaryotic cells.

Complete answer:
Actin is the monomeric subunit of two types of filament in the cell. The actin occurs in two forms, the monomeric G-actin which is globular and the polymeric F-actin which is fibrous. In the presence of magnesium, the G-actin polymerises to form the F-actin. Actin is a type of thin myofilament. Actin takes part in many important cellular processes such as muscle contraction, cell motility, cell division, cytokinesis, movement of organelles etc. It also helps in the maintenance and foundation of cell junction and cell shape.
Actin is a filament that is made up of actin protein, troponin and tropomyosin. It is also known as the thin filament and it is short in length. Actin is a globular protein build with a long beady structure which contains chains and the myosin. The interaction between the actin and myosin filaments helps to generate a muscle contraction. Myosin binds with actin at the binding site on the globular actin protein.
Hence, the correct option is true.

Note: Actin is a highly rich intracellular protein. Actin filaments are present abundantly below the plasma membrane where they make networks which give mechanical support.