Definition
Cell plasma or cytoplasm is the complete content of the cell with the exception of cell organelles. Cytoplasm is an organic fluid that forms the basic substance of every cell. Besides water, cytoplasm consists mainly of proteins, nutrients and enzymes that are essential for the cell’s function.
Function of the cell plasma
The cytoplasm forms the basic structure of a cell and gives it its shape by completely filling the cell. Every cell, both those of bacteria, plants and animals, consists of cytoplasm. Cytoplasm has a gel-like consistency.
It contains all the components of a cell. To the outside, the cytoplasm is separated from the extracellular space by the cell membrane. The cytoplasm itself consists of the cell fluid (cytosol), the cell organelles and the cytoskeleton.
The cytoskeleton is a stabilizing protein that forms a dynamic network and gives the cell structure. Cell organelles are all functional systems within a cell, such as the cell nucleus, mitochondria, endoplasmic reticulum and ribosomes. Organelles are typically enclosed by their own membrane and only occur in eukaryotes.
What are the components and what is the composition of the cell plasma?
The cytoplasm describes the organic substance within cells with the exception of all cell organelles, such as mitochondria and ribosomes. The cytoplasm has a liquid to gel-like consistency and constitutes the main part of a cell. This cell fluid (cytosol) is composed of various components.
The main component, approximately 80%, is water (H2O) and many dissolved substances such as sugar, electrolytes and nutrients. This is important to give the cell a shape and fill the volume within the cell membrane. About 10% of the cell plasma consists of proteins.
Proteins are essential as components of enzymes and are also involved in structural and transport processes of the cells. Fats (lipids) make up a small proportion of about 4%. Fats are required for the formation and maintenance of the cell membrane and are also the starting materials for other products, such as inflammation mediators.
Other components are also important, but they are only present in very low concentrations in the cell plasma. These include several ions, such as sodium (Na+) and chloride (Cl-). These charged particles ensure that the cytoplasm provides the right environment for various metabolic pathways.
In addition to the cell fluid, the cytoplasm also contains a stabilizing component called the cytoskeleton. This cytoskeleton consists of filamentous proteins that span the cell fluid and ensure the three-dimensional shape of the cell. The most important function of the cytoplasm is to give the cell its structure: because there is no air inside a cell, the cytoplasm must fill all the empty spaces of the cell with fluid.
In addition, many substances are transported through the interior of a cell, with the cytoplasm serving as a medium for mass transport. The cell stores water and nutrients in the form of cytoplasm and can react to external influences by changing the composition of the cytoplasm. Many important cell components are assembled in the cytoplasm in the form of proteins. For this purpose, the genetic material contained in the cell nucleus is transcribed into an RNA, which is then ejected and serves in the cytoplasm as a construction manual for protein biosynthesis. In addition to the assembly of proteins, the transport of various substances and the storage of different substances, the cytoplasm also has another important function: the degradation of metabolites produced during metabolism and other substances that are not needed.
