What is Actin?
Actin is a popular multifunctional globular protein found in eukaryotic cells and helps in cell motion cell and cell division thus providing mobility to the body.
Actin is a partial subdivision of the cell’s other two types of filaments. G actin I.e Globular Actin and F Actin I.e Filamentous Actin. Both the G Actin and F Actin are important for cellular functions like cell division, mobility, and contractions of cells.
Acting proteins are found in the A and I bands of the sarcomere. Actin proteins are short. I.e 0.005 in diameter and 2.26m in length.There are no cross Bridges seen in Actin Filament.The actin surface is smooth.
The primary role of Actin in cells is to form long chains, called filaments, that contribute to various functions of cell structure, cell migration, and cell replication. cells. Actin is a protein found in the cytoplasm and nucleus of eukaryotes. Actin is abundantly found in most cells and comprises 1 to 5 percent of the total protein mass of the cells and 10% of the muscle cells in our body.
Many diseases in eukaryotes are also caused by allelic mutations in genes that allow the production of Actin or other related proteins. Mutations in non-identical genes that allow the body to produce Actin that cause muscle disease, deafness, and uneven changes in measurements and heart function in humans.
What is Myosin?
Myosin is called motor protein and with the help of Actin protein, it helps in muscle contraction and other mortality processes in eukaryotic organisms.
Myosin proteins are found in the A band of the sarcomere. Myosin proteins are longer filaments I.e 0.01 in diameter and 4-5 m in length. Myosin filaments form bridges and have a rough surface.
The full structure of Myosin protein is divided into three parts, Head, neck, and tail. The head region links filamentous actin and uses ATP hydrolysis to generate a force to travel with the filament towards the plus end. The neck part act as a link, as a lever arm that helps to convert the force generated by the action of the catalytic motor. The neck part of protein also helps in binding sites of myosin light chains. And lastly, the protein’s tail part helps manage motor activities.
Difference Between Actin and Myosin
- Actin proteins are multifunctional globular proteins that help in cell division and also in providing mobility to the body whereas Myosin is called motor protein and with the help of Actin protein, which aids in muscle contraction.
- Actin protein is thinner and shorter in size than Myosin protein.
- The surface of Actin protein is observed smooth whereas myosin protein has a rough surface.
- Actin protein is located in cell walls, cell membrane, muscle fiber, and also in muscle microfilaments. On the other hand, Myosin is located in muscle cells.
- Actin proteins are large in number whereas myosin proteins are sparse in quantity.
Comparison Between Actin and Myosin
| Parameters Of Comparison | Actin | Myosin |
| Definition | Actin is the multifunctional globular protein that helps in cell motion and cell division in the body thus providing mobility to the body. | Myosin is also called motor protein and with help of Actin protein, it helps in muscle contraction in the human body. |
| Found In | Actin proteins are found in the A and I bands of the sarcomere. | Myosin proteins are found in the A band of the sarcomere. |
| Size | Actin proteins are short. I.e 0.005 in diameter and 2.26m in length. | Myosin proteins are longer filaments I.e 0.01 in diameter and 4-5 m in length. |
| Surface | Actin proteins have smooth surfaces. | Myosin protein has a rough surface. |
| Cross Bridges | There are no cross Bridges seen in Actin Filament. | Myosin filaments, form bridges. |