We explain what the cytoplasm is and the regions into which it is divided. Also, its different functions and what its structure is like.
What is cytoplasm?
The interior of cells (protoplasm) is called cytoplasm, which occupies the area between the cell nucleus and the plasma membrane. It is about a colloidal dispersion of a fluid called cytosol or halioplasm grainy in appearance and very fine in its composition. It contains the various organelles of the cell and many of its molecular reactions occur.
The cytosol is composed of 70% water, without form or stable structure and inside is the cytoskeleton: a set of filaments of protein origin that gives internal order to the cell and allows its movement, connecting its different corners to the nucleus of the cell.
Commonly, the cytoplasm can be divided into two regions:
- Ectoplasm The outermost region of the same, close to the plasma membrane, and more gelatinous in texture. It is usually involved in cell movement.
- Endoplasm The innermost region of the cytoplasm, organized around the nucleus, and where most cellular organelles are located.
The cytoplasm It is common to both eukaryotic and prokaryotic cells although they contain different types of organelles.
See also: Meiosis
Cytoplasm function
The cytoplasm fulfills various functions, the most basic of which is to constitute the interior of the cell, its “body.” Besides, The different cellular organelles are housed there and communication occurs between them, and various cellular metabolic reactions also take place, many of which occur in the endoplasmic reticulum.
At the same time, the cytoplasm allows the mobility of organelles and its replication in the event of cell division, and it is, together with the plasma membrane, the last thing to separate during the process of mitosis.
Cytoplasm structure
The cytoplasm contains the organelles of the cell, which are usually:
- Core. In eukaryotic cells, there is a well-defined nucleus that houses all the genetic material and plays a key role in cellular reproduction. The nucleus is wrapped in a membrane and is surrounded by nucleoplasm, thus allowing the exchange of matter with the cytoplasm. Prokaryotic cells, on the other hand, do not have a nucleus.
- Plasma membrane. It is a membrane with selective permeability, which covers the cell and separates the inside from the outside, giving entry to desired substances and exit to metabolic waste.
- Cell wall. Plant and fungal cells have a rigid cell wall, outside the plasma membrane, composed of cellulose (plants) or chitin (fungi).
- Mitochondria. They are the energy centers of the cell, where the synthesis of ATP (Adenosine triphosphate, the chemical energy molecule) occurs, using nutrients from the environment. This is known as cellular respiration.
- Chloroplasts. Plants carry out photosynthesis, so their cells have chloroplasts: organelles that contain chlorophyll to obtain energy from sunlight, and which gives them their usual green color.
- Lysosomes. They fulfill the function of degrading the molecular material that enters the cell (heterophagy) or produced by the cell itself (autophagy), in what is known as cellular digestion.
- Golgi apparatus. Similar to animal and plant cells, it serves as a transport channel for proteins and other substances, through a system of vesicles that goes in and out of the cytoplasm.
- Endoplasmic reticulum. It is a series of flattened and interconnected tubules and sacs, made from fatty acids. It is classified into two different domains: the rough endoplasmic reticulum, covered with ribosomes to carry out the cell's protein synthesis; and the smooth endoplasmic reticulum, responsible for the synthesis of lipids, the absorption and release of calcium from the cell and other molecular functions.
- Centriole It is a cylindrical organelle, made up of three triplets of microtubules that belong to the cytoskeleton, located in the cytoplasm (in the diplosoma). These ducts serve for transport between organelles and as a guiding axis for the processes of mitosis or cell division.
- Chromatin This is the name given to the set of DNA and other proteins that is in the nucleus itself, that is, the cellular genetic material.
- Vacuole. These are deposits of enzymes, sugars, proteins or water, which are used for storage and various processes by the cell. In plant cells there is a single, large one in the center of the cell; Animals, on the other hand, have several small vacuoles in the cytoplasm.
