The nuclear membrane , Sometimes called a nuclear envelope, is a structure composed of lipids that contains the genetic material of the so-called Eukaryotic cells , The cells that are formed by a nucleus and the membrane that covers it.
It is the porous structure that surrounds the nucleus. It consists of two layers that merge and have small holes (pores) through which the cytoplasm communicates with the inside of the nucleus through the passage of certain molecules of organic compounds.
It regulates the passage of genetic information allowing the passage of proteins and nucleic acids, keeping the nucleus inside the DNA.
The cell is the basic unit of life. All living things are composed of cells. Some beings are composed of a single cell, such as bacteria and viruses. Others like humans are made by millions of cells.
The cell is composed of a nucleus, which contains chromosomal material inside it or DNA , Called chromatin. It also contains the nucleolus that is composed of RNA (ribonucleic acid) and proteins that form the Ribosomes .
This is surrounded by a semi-spherical double membrane (nuclear membrane); The cytoplasm, composed of Both organic and inorganic substances , And that contains different cellular organelles, that fulfill diverse functions within the cell. All this is surrounded by a membrane arranged around it, which protects and regulates the passage of nutrients and waste disposal.
The cell can perform functions such as nutrition, reproduction and can transmit genetic information. The cell as such is a complete organism. The cell is reproduced by division, that is, two cells are generated from each cell.
The interactions between the nucleus and the outer part are made in the so-called nuclear membrane. This membrane surrounds the nucleus and has pores through which an interaction occurs of molecules that are responsible for very important functions of the cell.
Among the molecules involved in these processes are proteins, which are composed of amino acids, and are necessary for the proper functioning of the human body. They are the basis of body structures, such as hair or skin, as well as enzymes and antibodies.
Functions of the nuclear membrane
In the cell two processes are executed, the DNA transcription in RNA within the nucleus, and the translation of RNA into protein in the cytoplasm. These processes are separated by the nuclear membrane.
The cytoplasm is the fluid within the cell, but external to the nucleus, where most of the cell's chemical reactions occur.
The pores it possesses are complex structures made of proteins capable of regulating the exchange of molecules, ions, water and ATP between the cytoplasm and the nucleus. It is said that these pores are not static but rather flexible and are able to select the type of molecules they let pass, thanks to the receptors, which recognize them.
The nuclear membrane controls the exit of DNA from the cell nucleus and blocks the entry of cytoplasmic enzymes and proteins.
Parts of the nuclear membrane
It is composed of two layers, the inner and the outer, separated by a distance of about 20 to 40 nanometers.
These layers have small holes or nuclear pores that allow the passage of molecules in and out of the nucleus, and the transport of proteins, as well as serve as a connection between the outer membrane and the inner membrane. The space between the two membranes is called the perinuclear cistern.
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The internal nuclear membrane, in turn, has a face covered by another structure called nuclear lamina. This structure is composed of proteins called laminas, whose thickness oscillates between 15 and 80 nm.
Its function is to provide stability to the entire membrane or nuclear envelope and is also associated with DNA duplication, RNA transcription, organization or physical arrangement of chromatin, regulation of the cell cycle, cell development and differentiation, Nuclear migration and apoptosis.
The latter is an ordered process of cell death, necessary to eliminate diseased cells by viruses, as well as those that are potentially cancerous, so that the organism removes them from itself to maintain balance.
8 Characteristics of the nuclear membrane
Among the characteristics of the nuclear membrane we have:
- Membrane structure consisting of two membranes with pores.
- Ribosomes (proteins) that synthesize proteins from genetic information.
- Chromatin, which is a substance within the chromosome, and consists of a DNA protein. It is located in the inner layer and contains the DNA and proteins attached to it. Chromosomes are a cellular structure that contains the genes. Except for eggs and sperm, human cells contain 46 chromosomes in each cell.
- Perinuclear space or cistern, which is the space between the inner and outer membrane
- Complex of the nuclear pore, which are the holes through which the nucleus communicates with the cytoplasm. They are made up of proteins, more than 50.
- Nucleoplasm, the part that is in contact with the inner layer of the membrane, and contains the chromatin fiber and the nucleolus.
- Cytoplasm, which is the part that is in contact by the outside of the nuclear membrane.
- Nuclear sheet, which functions as a support or support for the nuclear envelope. It is formed by filaments and can disintegrate and reappear during the process of cell division.
The study of all these structures and, in general, those related to the cell and its components, processes and characteristics are of vital importance for science and humanity.
To give an example, they can be the key to make great advances in the fight against cancer, once it is possible to control the growth and division of tumor cells.
References
- 10 Characteristics of the Nuclear Membrane. Recovered from: caracteristicas.co.
- Cell Membrane. Retrieved from: ncbi.nlm.nih.gov.
- Evans, D. et al. (2004). The Nuclear Envelope. Ontario, Taylor & Francis.
- Function of The Nuclear Envelope / Nuclear Membrane. Recovered from: softschools.com.
- Nuclear Envelope Function. Retrieved from: plant-biology.com.