cytoplasm

Article

July 5, 2022

The cytoplasm (cytoplasm) refers to the region other than the cell nucleus of the protoplasm, which is the part surrounded by the cell membrane of the cell. In addition to the cytosol, the cytoplasm contains various organelles, especially in eukaryotic cells. Many organelles are separated from other parts by biological membranes. The cytoplasm is the place where most of the various metabolisms in the body and cell activities such as cell division occur. It is often misused intentionally as a cytosol. The portion of the cytoplasm other than organelles is called the cytosol or cytoplasmic gel. The cytosol is a complex mixture consisting of the cytoskeleton, lysed molecules, water, etc., which occupy a large part of the cell volume. The cytosol is a gel, with a network of fibers scattered throughout the solution. Due to this pore-like network and the high concentration of macromolecules such as proteins, a phenomenon called molecular crowding occurs in the cytosol, and it is not an ideal solution. The effect of this crowding also alters the reaction inside the cytosol.

Configuration

There are three main components to the cytoplasm. Cytosol, organelles, inclusion bodies.

Cytosol

The cytosol is the portion of the cytoplasm other than organelles and inclusion bodies. The cytosol is a translucent liquid with various cytoplasmic elements floating in it. The cytosol occupies about 70% of the volume of a typical cell and consists of water, salts, small molecule organic compounds and the like. The cytoplasm also contains large structures such as protein fibers and water-soluble proteins that form the cytoskeleton, ribosomes, and proteasomes, and vaults that are not yet well understood. The inner part of the cytoplasm is rich in granules and relatively fluid, which is called the endoplasm. On the other hand, the outer part is called the ectoplasm.

Organelles

Organelles are the parts of a cell that have unique functions and are surrounded by biological membranes. Major organelles include mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes. Other plant cells include chloroplasts and vacuoles.

Inclusion bodies

Inclusion bodies are aggregates of insoluble substances that float in the cytosol. Also called intracellular inclusion. There are different types of inclusion bodies depending on the species and cell type. For example, crystals of calcium oxalate and silicon dioxide found in plants (plant opal), as well as granules of energy storage substances such as starch, glycogen, and polyhydroxybutyric acid (PHB). Particularly widespread are oil droplets (or lipid droplets). These are spherical droplets, a mixture of lipids and proteins, found in both prokaryotes and eukaryotes. Used for the preservation of lipids such as fatty acids and sterols. In adipocytes, which are cells specialized in lipid storage, oil droplets occupy most of the volume.

Footnote

References

Alberts, Bruce et al (2003). Essential Cell Biology (2nd ed.). Garland Science. ISBN 081533480X (Translated by Keiko Nakamura and Kenichi Matsubara, "Cell Biology Original Book 2nd Edition") Elain N Marieb and Latja Hoehn (2007). Human Anatomy & Physiology (7th ed.). Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman, Inc. ISBN 978-0321518118

External link

What is cytoplasm?-By Genevieve Theirs -2002 Luby-Phelps K. Cytoarchitecture and physical properties of cytoplasm: volume, viscosity, diffusion, intracellular surface area. Int Rev Cytol. 2000; 192: 189-221.