The nucleus, its structure and biological role.

The core consists of 1) surface of the core apparatus(it contains: 2 membranes, perinuclear spaces, pore complexes, lamina.) 2) karyoplasma(nucleoplasm) 3) chromatin(it contains euchromatin and heterochromatin) 4) nucleolus(granular and fibrillar components.)

The nucleus is a cell structure that performs the function of storing and transmitting information, and also regulates all the life processes of the cell. The nucleus carries genetic (hereditary) information in the form of DNA. The nuclei are usually spherical or ovoid in shape. The nucleus is surrounded by a nuclear membrane. The nuclear envelope is permeated with nuclear pores. Through them, the nucleus exchanges substances with the cytoplasm (the internal environment of the cell). The outer membrane passes into the endoplasmic reticulum and can be studded with ribosomes. The ratio of the sizes of the nucleus and the cell depends on the functional activity of the cell. Most cells are mononuclear. Cardiomyocytes can be binucleate. Ciliates are always binucleate. They are characterized by nuclear dualism (that is, the nuclei differ in structure and function). The small nucleus (generative) is diploid. It provides only the sexual process in ciliates. The large (vegetative) nucleus is polyploid. It regulates all other life processes. The cells of some protozoa and skeletal muscle cells are multinucleated.

P.A.Y. or karyoteka ) has a microscopic thickness and is therefore visible under a light microscope. The superficial apparatus of the nucleus includes:

a) nuclear membrane, or karyolemma;. b) steam complexes; c) peripheral lamina densa (LPD), or lamina .

(1) Nuclear envelope (karyolemma). consists of 2 membranes - outer and inner, separated by the perinuclear space. Both membranes have the same fluid-mosaic structure as the plasma membrane and differ in the set of proteins. Among these proteins are enzymes, transporters and receptors. The outer nuclear membrane is a continuation of the GR membranes and can be studded with ribosomes, on which protein synthesis occurs. On the cytoplasmic side, the outer membrane is surrounded by a network of intermediate (vi-mentin) fipaments. Between the outer and inner membranes there is a perinuclear space - a cavity 15-40 nm wide, the contents of which communicate with the cavities of the EPS channels. The composition of the perinuclear space is close to the hyaloplasm and may contain proteins synthesized by ribosomes. home karyolemma function - isolation of hyaloplasm from karyoplasm. Special nuclear membrane proteins located in the area nuclear pores, carry out transport function. The nuclear envelope is penetrated by nuclear pores, through which the karyoplasm and hyaloplasm communicate. To regulate such communication, the pores contain (2) pore complexes. They occupy 3-35% of the surface of the nuclear envelope. The number of nuclear pores with pore complexes is a variable value and depends on the activity of the nucleus. In the region of nuclear pores, the outer and inner nuclear membranes merge. The set of structures associated with a nuclear pore is called nuclear pore complex. A typical pore complex is a complex protein structure - containing more than 1000 protein molecules. At the center of the pore is located central protein globule(granule), from which thin fibrils extend radially to peripheral protein globules, forming a pore diaphragm. Along the periphery of the nuclear pore there are two parallel ring structures with a diameter of 80-120 nm (one on each surface of the karyolemma), each of which is formed 8 protein granules(globules).

The protein globules of the feather complex are divided into central And peripheral . By using peripheral globules macromolecules are transported from the nucleus to the hyaloplasm. (fixed in the membrane by a special integral protein. From these granules they converge towards the center protein fibrils, forming a partition - pore diaphragm)

It involves special proteins of peripheral globules - nucleoporins. Peripheral globules contain a special protein - a carrier of t-RNA molecules

Central globule specializes in the transport of mRNA from the nucleus to the hyalopdasm. It contains enzymes involved in the chemical modification of mRNA - its processing.

Granules of pore complexes are structurally associated with proteins of the nuclear lamina, which is involved in their organization

Functions of the nuclear pore complex:

1. Ensuring regulation of selective transport between the cytoplasm and the nucleus.

2. Active transfer V protein core

3. Transfer of ribosomal subunits into the cytoplasm

(3) PPP or lamina

layer 80-300 nm thick. adjoins from the inside to the inner nuclear membrane. The inner nuclear membrane is smooth, its integral proteins are associated with the lamina (peripheral lamina densa). The lamina consists of special intertwined lamin proteins that form the peripheral karyoskeleton. Lamin proteins belong to the class of intermediate filaments (skeletal fibrils). In mammals, 4 types of these proteins are known: lomimas A, B, B 2 and C. These proteins enter the nucleus from the cytoplasm. Lamins of different types interact and form a protein network under the inner membrane of the nuclear envelope. With the help of lamins “B”, the PPP is connected to the special integral of the protein nuclear membrane. The proteins of the peripheral holobules “inside the ring” of the pore complex also interact with the PPP. Telomeric sections of chromosomes are attached to lamin “A”.

Functions of the lamina: 1) maintain the shape of the core. (even if the membrane is destroyed, the core, due to the lamina, retains its shape and the pore complexes remain in place.

2) serves as a component of the karyoskeleton

3) participating in the assembly of the nuclear membrane (formation of the karyolema) during cell division.

4) in the interphase nucleus, chromatin is attached to the lamina. Thus, the lamina provides the function of fixing chromatin in the nucleus (ensuring the orderly laying of chromatin, participates in the spatial organization of chromatin in the interphase nucleus). Lamin A interacts with telomeric regions of chromosomes.

5) providing structures with the organization of pore complexes.

import and export of proteins.

To the core through nuclear pores enter: enzyme proteins synthesized by cytoplasmic ribosomes that participate in the processes of replication and repair (repair of damage in DNA); enzyme proteins involved in the transcription process; repressor proteins that regulate the transcription process; histone proteins (which are associated with a DNA molecule and form chromatin); proteins that make up the ribosomal subunits: nuclear matrix proteins that form the karyoskeleton; nucleotides; ions of mineral salts, in particular Ca and Mg ions.

From the core mRNAs are released into the cytoplasm. tRNA and ribosomal subunits, which are ribonucleoprotein particles (protein-linked rRNA).

5. Chemical composition and structural organization of chromatin. levels of compaction. human chromosomes, their structure and classification.

In the cell nucleus, small grains and clumps of material are stained with basic dyes.

Chromatin is a deoxyribonucleoprotein (DNP) and consists of DNA linked to mi-histone proteins or non-histone proteins. Histones and DNA are combined into structures called nucleosomes. Chromatin corresponds to chromosomes, which in the interphase nucleus are represented by long twisted threads and are indistinguishable as individual structures. The severity of spiralization of each chromosome is not the same along their length. The implementation of genetic information is carried out by despiralized sections of chromosomes.

chromatin classification:

1) euchromatin(active despiralized. Inf reading (transcription) occurs on it. In the nucleus it is revealed as lighter areas closer to the center of the nucleus) It is assumed that the DNA that is genetically active in interphase is concentrated in it. Euchromatin corresponds to segments of chromosomes that despiralized And open for transcription.

2) heterochromatin(non-working spiralized, condensed, more compact In the core, it is revealed in the form of lumps on the periphery.) divided by:constitutive (always inactive, never turns into euchromatin) and Optional (under certain conditions or at certain stages of the immune cycle it can turn into euchromatin). located closer to the core shell, more compact. An example of the accumulation of heterochromatin faculty is the Barr body - an inactivated X chromosome in female mammals, which is tightly coiled and inactive in interphase.

Thus, based on the morphological characteristics of the nucleus (based on the ratio of the content of eu- and heterochromatin), it is possible to assess the activity of transcription processes, and, consequently, the synthetic function of the cell.

Chromatin and chromosomes are deoxyribonucleoproteins (DNPs), but chromatin is an uncoiled state and chromosomes are a coiled state. There are no chromosomes in the interphase nucleus; chromosomes appear when the nuclear membrane is destroyed (during division).

Chromosome structure:

chromosomes are the most packed state of chromatin.

In chromosomes there are primary constriction (centromere), dividing the chromosome into two arms. The primary constriction is the least spiraled part of the chromosome; spindle threads are attached to it during cell division. Some chromosomes have deep secondary constrictions, separating small sections of chromosomes called satellites. In the region of secondary constrictions there are genes encoding information about r-RNA, therefore secondary constrictions of chromosomes are called nucleolar organizers.

Depending on the location of the centromere, three types of chromosomes are distinguished:

1) metacentric (have shoulders of equal or almost equal size);

2) submetacentric (have shoulders of unequal size);

3) acrocentric (have a rod-shaped shape with a short, almost invisible second arm);

The ends of the chromosome arms are called telomeres

Levels of chromatin compupation:

1. Nucleosomal- Two and a half turns of the DNA double helix (146-200 base pairs) are wound around the outside of the protein core, forming a nucleosome. Each histone is represented by two molecules. The DNA is wound around the outside of the core, forming two and a half turns. The DNA section between nucleosomes is called a linker and has a length of 50-60 nucleotide pairs. The thickness of the nucleosome filament is 8-11 nm.

2. Nucleomeric. The nucleosomal structure twists to form a superhelix. Another histone protein HI, lying between the nucleosomes and associated with the linker, takes part in its formation. One molecule of histone HI is attached to each linker. HI molecules in complex with linkers interact with each other and cause supercoiling nucleosome fibril.

As a result, a chromatin fibril is formed, the thickness of which is 30 nm (DNA is compacted 40 times). Supercoiling occurs in two ways. 1) a nucleosomal fibril can form a second-order helix, which has the shape of a solenoid; 2) 8-10 nucleosomes form a large compact structure - nucleomer. This level does not allow the synthesis of RNA with nucleomeric DNA (transcription does not occur).

3. Chromomeric(loop structure). The chromatin fibril forms loops that are linked to each other using special non-histone proteins, or loop centers - chromomeres. Thickness 300 nm.

4. Lame- is formed as a result of the convergence of chromomeres along the length. Chromonema contains one giant DNA molecule in complex with proteins, i.e. deoxyribonucleoprotein fibril - DNP (400 nm).

5. Chromatid- chromonema folds several times to form the body of the chromatid (700 nm). After DNA replication, the chromosome contains 2 chromatids.

6. Chromosomal(1400 nm). Consists of two chromatids. The chromatids are connected by a centromere. When a cell divides, the chromatids separate and end up in different daughter cells.

human chromosomes

Karyotype is a set of characteristics (number, size, shape, etc.) of a complete set of chromosomes inherent in the cells of a given biological species (species karyotype), this organism ( individual karyotype) or line (clone) of cells.

For the procedure for determining the karyotype, any population of dividing cells can be used; to determine the human karyotype, either mononuclear leukocytes extracted from a blood sample, the division of which is provoked by the addition of mitogens, or cultures of cells that rapidly divide normally (skin fibroblasts, bone marrow cells) are used.

karyotype – diploid set of chromosomes, characteristic of somatic cells of organisms of a given species, which is a species-specific feature and is characterized by a certain number and structure of chromosomes.

The chromosome set of most cells is diploid (2n) - this means that each chromosome has a pair, i.e. homologous chromosome. Typically, a diploid (2n) set of chromosomes is formed at the time of fertilization (one of a pair of chromosomes from the father, the other from the mother). Some cells are triploid (Tp), for example endosperm cells.

A change in the number of chromosomes in a person’s karyotype can lead to various diseases. Most common chromosomal disease a person has Down syndrome, caused by trisomy (another identical, extra one is added to a pair of normal chromosomes) on the 21st chromosome. This syndrome occurs with a frequency of 1-2 per 1000.

Trisomy on chromosome 13 is known - Patau syndrome, as well as on the 18th chromosome - Edwards syndrome, in which the viability of newborns is sharply reduced. They die in the first months of life due to multiple developmental defects.
Quite often, a change in the number of sex chromosomes occurs in humans. Among them, monosomy X is known (only one of a pair of chromosomes is present (X0)) - this is Shereshevsky-Turner syndrome. Trisomy X is less common and Klinefelter syndrome(ХХУ, ХХХУ, ХУУ, etc.)

6. Hyaloplasm. Organelles, their classification. Biological membranes.

hyaloplasm is part of the cytoplasm of animal and plant cells that does not contain structures visible in a light microscope.

Hyaloplasma(hyaloplasma; from Greek hyalinos - transparent) makes up approximately 53-55% of the total volume of cytoplasm (cytoplasma), forming a homogeneous mass complex composition. The hyaloplasm contains proteins, polysaccharides, nucleic acids, and enzymes. With the participation of ribosomes, proteins are synthesized in the hyaloplasm, and various intermediate metabolic reactions occur. The hyaloplasm also contains organelles, inclusions and the cell nucleus.

The main role of hyaloplasm is the unification of all cellular structures in relation to their chemical interaction and provision of transport biochemical processes.

Organelles (organellae) are obligatory microstructures for all cells that perform certain vital functions. Distinguish membrane and non-membrane organelles.

TO membrane organelles , delimited from the surrounding hyaloplasm by membranes, include the endoplasmic reticulum, Golgi complex, lysosomes, peroxisomes, and mitochondria.

Endoplasmic reticulum represents a single continuous structure, formed by the system cisterns, tubules and flattened sacs. In electron micrographs, granular (rough, granular) and non-granular (smooth, agranular) endoplasmic reticulum are distinguished. The outer side of the granular network is covered with ribosomes; the non-granular side is devoid of ribosomes. The granular endoplasmic reticulum synthesizes (on ribosomes) and transports proteins. The non-granular network synthesizes lipids and carbohydrates and participates in their metabolism (for example, steroid hormones in the adrenal cortex and Leydig cells (sustenocytes) of the testicles; glycogen in liver cells). One of the most important functions of the endoplasmic reticulum is the synthesis of membrane proteins and lipids for all cellular organelles.

Golgi complex is a collection of sacs, vesicles, cisterns, tubes, plates, limited biological membrane. The elements of the Golgi complex are connected to each other by narrow channels. In the structures of the Golgi complex, the synthesis and accumulation of polysaccharides and protein-carbohydrate complexes occur, which are removed from the cells. This is how secretory granules are formed. The Golgi complex is present in all human cells, except erythrocytes and horny scales of the epidermis. In most cells, the Golgi complex is located around or near the nucleus; in exocrine cells, it is located above the nucleus, in the apical part of the cell. The internal convex surface of the Golgi complex structures faces the endoplasmic reticulum, and the external, concave surface faces the cytoplasm.

The membranes of the Golgi complex are formed by the granular endoplasmic reticulum and are transported by transport vesicles. From outside In the Golgi complex, secretory vesicles are constantly budding, and the membranes of its cisterns are constantly renewed. Secretory vesicles supply membrane material for the cell membrane and glycocalyx. This ensures renewal of the plasma membrane.

Lysosomes are vesicles with a diameter of 0.2-0.5 microns, containing about 50 types of various hydrolytic enzymes (proteases, lipases, phospholipases, nucleases, glycosidases, phosphatases). Lysosomal enzymes are synthesized on the ribosomes of the granular endoplasmic reticulum, from where they are transported by transport vesicles to the Golgi complex. Primary lysosomes bud from the Golgi complex vesicles. Maintained in lysosomes acidic environment, its pH ranges from 3.5 to 5.0. The membranes of lysosomes are resistant to the enzymes contained in them and protect the cytoplasm from their action. Violation of the permeability of the lysosomal membrane leads to the activation of enzymes and severe damage to the cell, including its death.

In secondary (mature) lysosomes (phagolysosomes), biopolymers are digested into monomers. The latter are transported through the lysosomal membrane into the hyaloplasm of the cell. Undigested substances remain in the lysosome, as a result of which the lysosome turns into a so-called residual body of high electron density.

Mitochondria(mitochondrii), which are the “energy stations of the cell,” are involved in the processes of cellular respiration and the conversion of energy into forms available for use by the cell. Their main functions are oxidation organic matter and synthesis of adenosine triphosphoric acid (ATP). There are many large mitochondria in cardiomyocytes and muscle fibers of the diaphragm. They are located in groups between myofibrils, surrounded by glycogen granules and elements of the non-granular endoplasmic reticulum. Mitochondria are organelles with double membranes (each about 7 nm thick). Between the outer and inner mitochondrial membranes there is an intermembrane space 10-20 nm wide.

To non-membrane organelles include cell center eukaryotic cells and ribosomes present in the cytoplasm of both eukaryotic and prokaryotic cells.

Ribosome is a round ribonucleoprotein particle with a diameter of 20-30 nm. It consists of small and large subunits, the combination of which occurs in the presence of messenger RNA (mRNA). One molecule of mRNA usually links several ribosomes together like a string of beads. This structure is called polysome. Polysomes are freely located in the main substance of the cytoplasm or attached to the membranes of the rough cytoplasmic reticulum. In both cases, they serve as a site of active protein synthesis.

70S ribosomes are found in prokaryotes and in chloroplasts and mitochondria of eukaryotes. 8OS ribosomes, somewhat larger, are found in the cytoplasm of eukaryotes. During protein synthesis, ribosomes move along the mRNA. The process is more efficient if not one, but several ribosomes move along the mRNA. Such chains of ribosomes on mRNA are called polyribosomes, or polysomes.

MEMBRANES:

all membranes form lipoprotein films; have a double layer of lipids.

The membranes contain up to 20% water. lipids.

Membranes consist of three classes of lipids: phospholipids, glycolipids and cholesterol. Phospholipids and glycolipids are composed of two long hydrophobic hydrocarbon tails that are connected to a charged hydrophilic head. Cholesterol gives the membrane rigidity by occupying the free space between the hydrophobic tails of lipids and preventing them from bending. Therefore, membranes with a low cholesterol content are more flexible, while those with a high cholesterol content are more rigid and fragile.

Cell membranes are often asymmetrical, that is, the layers differ in lipid composition, the transition of an individual molecule from one layer to another (the so-called flip flop) difficult. The composition and orientation of membrane proteins differ.

One of the most important functions biomembranes - barrier. For example, the peroxisome membrane protects the cytoplasm from peroxides that are dangerous to the cell.

Another important property biomembranes - selective permeability.

In the process of evolution, they underwent a number of changes. The appearance of new organelles was preceded by transformations in the atmosphere and lithosphere of the young planet. One of the significant acquisitions was the cell nucleus. Eukaryotic organisms received, thanks to the presence of separate organelles, significant advantages over prokaryotes and quickly began to dominate.

The cell nucleus, the structure and functions of which differ slightly in different tissues and organs, has made it possible to improve the quality of RNA biosynthesis and the transmission of hereditary information.

Origin

To date, there are two main hypotheses about the formation of a eukaryotic cell. According to the symbiotic theory, organelles (such as flagella or mitochondria) were once separate prokaryotic organisms. The ancestors of modern eukaryotes absorbed them. As a result, a symbiotic organism was formed.

The nucleus was formed as a result of protrusion into the cytoplasmic region and was a necessary acquisition on the way to the cell’s development of a new method of nutrition, phagocytosis. Food capture was accompanied by an increase in the degree of cytoplasmic mobility. Genophores, which were genetic material prokaryotic cells and attached to the walls, fell into the zone of strong “current” and needed protection. As a result, a deep invagination of a section of the membrane containing attached genophores was formed. This hypothesis is supported by the fact that the core shell is inextricably linked with cytoplasmic membrane cells.

There is another version of the development of events. According to the viral hypothesis of the origin of the nucleus, it was formed as a result of infection of an ancient archaeal cell. A DNA virus penetrated into it and gradually gained complete control over life processes. Scientists who consider this theory more correct provide a lot of arguments in its favor. However, to date there is no comprehensive evidence for any of the existing hypotheses.

One or more

Most modern eukaryotic cells have a nucleus. The vast majority of them contain only one such organelle. There are, however, cells that have lost their nucleus due to certain functional features. These include, for example, red blood cells. There are also cells with two (ciliates) and even several nuclei.

Structure of the cell nucleus

Regardless of the characteristics of the organism, the structure of the nucleus is characterized by a set of typical organelles. It is separated from the internal space of the cell by a double membrane. Its internal and external layers merge in some places, forming pores. Their function is to exchange substances between the cytoplasm and the nucleus.

The space of the organelle is filled with karyoplasm, also called nuclear juice or nucleoplasm. It houses chromatin and the nucleolus. Sometimes the last of the named organelles of the cell nucleus is not present in a single copy. In some organisms, on the contrary, nucleoli are absent.

Membrane

The nuclear envelope is formed by lipids and consists of two layers: outer and inner. Essentially it's the same cell membrane. The nucleus communicates with the channels of the endoplasmic reticulum through the perinuclear space, a cavity formed by two layers of the membrane.

The outer and inner membranes have their own structural features, but in general they are quite similar.

Closest to the cytoplasm

The outer layer passes into the membrane of the endoplasmic reticulum. Its main difference from the latter is that it is much more high concentration proteins in structure. The membrane, in direct contact with the cytoplasm of the cell, is covered with a layer of ribosomes on the outside. It is connected to the inner membrane by numerous pores, which are rather large protein complexes.

Inner layer

The membrane facing the cell nucleus, unlike the outer one, is smooth and not covered with ribosomes. It limits the karyoplasm. Feature inner membrane - a layer of the nuclear lamina lining it on the side in contact with the nucleoplasm. This specific protein structure maintains the shape of the shell, is involved in the regulation of gene expression, and also facilitates the attachment of chromatin to the nuclear membrane.

Metabolism

The interaction between the nucleus and the cytoplasm occurs through They are quite complex structures formed by 30 proteins. The number of pores on one core may vary. It depends on the type of cell, organ and organism. Thus, in humans, the cell nucleus can have from 3 to 5 thousand pores; in some frogs it reaches 50,000.

The main function of pores is the exchange of substances between the nucleus and the rest of the cell. Some molecules penetrate through pores passively, without additional energy expenditure. They are small in size. Transporting large molecules and supramolecular complexes requires the expenditure of a certain amount of energy.

RNA molecules synthesized in the nucleus enter the cell from the karyoplasm. IN reverse direction proteins necessary for intranuclear processes are transported.

Nucleoplasm

The structure of nuclear sap changes depending on the state of the cell. There are two of them - stationary and arising during the period of division. The first is characteristic of interphase (time between divisions). At the same time, the nuclear juice is uniformly distributed nucleic acids and unstructured DNA molecules. During this period, the hereditary material exists in the form of chromatin. The division of the cell nucleus is accompanied by the transformation of chromatin into chromosomes. At this time, the structure of the karyoplasm changes: the genetic material acquires a certain structure, the nuclear membrane is destroyed, and the karyoplasm mixes with the cytoplasm.

Chromosomes

The main functions of the nucleoprotein structures of chromatin transformed during division are the storage, implementation and transmission of hereditary information contained in the cell nucleus. Chromosomes are characterized by a specific shape: they are divided into parts or arms by a primary constriction, also called the coelomere. Based on their location, three types of chromosomes are distinguished:

• rod-shaped or acrocentric: they are characterized by the placement of the coelomere almost at the end, one arm is very small;
• multi-armed or submetacentric have shoulders of unequal length;
• equilateral or metacentric.

The set of chromosomes in a cell is called a karyotype. For each type it is fixed. In this case, different cells of the same organism can contain a diploid (double) or haploid (single) set. The first option is typical for somatic cells, which mainly make up the body. The haploid set is the privilege of germ cells. Somatic cells Humans contain 46 chromosomes, sex chromosomes - 23.

The chromosomes of the diploid set are in pairs. Identical nucleoprotein structures included in a pair are called allelic. They have same structure and perform the same functions.

The structural unit of chromosomes is the gene. It is a section of a DNA molecule that codes for a specific protein.

Nucleolus

The cell nucleus has one more organelle - the nucleolus. It is not separated from the karyoplasm by a membrane, but it is easy to notice when examining the cell using a microscope. Some nuclei may have multiple nucleoli. There are also those in which such organelles are completely absent.

The shape of the nucleolus resembles a sphere and is quite small in size. It contains various proteins. The main function of the nucleolus is the synthesis of ribosomal RNA and the ribosomes themselves. They are necessary to create polypeptide chains. Nucleoli are formed around special regions of the genome. They are called nucleolar organizers. This contains the ribosomal RNA genes. The nucleolus, among other things, is the place with the highest concentration of protein in the cell. Some proteins are necessary to perform organelle functions.

The nucleolus consists of two components: granular and fibrillar. The first represents the maturing ribosomal subunits. In the fibrillar center, the granular component surrounds the fibrillar component, located in the center of the nucleolus.

Cell nucleus and its functions

The role played by the nucleus is inextricably linked with its structure. The internal structures of the organelle jointly implement the most important processes in the cell. Genetic information is located here, which determines the structure and functions of the cell. The nucleus is responsible for the storage and transmission of hereditary information, which occurs during mitosis and meiosis. In the first case, the daughter cell receives a set of genes identical to the mother's. As a result of meiosis, germ cells with a haploid set of chromosomes are formed.

Other no less important function nuclei - regulation of intracellular processes. It is carried out as a result of control of the synthesis of proteins responsible for the structure and functioning of cellular elements.

The effect on protein synthesis has another expression. The nucleus, controlling the processes inside the cell, unites all its organelles into unified system with a well-functioning operating mechanism. Failures in it usually lead to cell death.

Finally, the nucleus is the site of synthesis of ribosomal subunits, which are responsible for the formation of the same protein from amino acids. Ribosomes are essential in the process of transcription.

It is a more perfect structure than the prokaryotic one. The emergence of organelles with their own membrane has made it possible to increase the efficiency of intracellular processes. The formation of a nucleus surrounded by a double lipid shell played a very important role in this evolution. important role. The protection of hereditary information by the membrane allowed the ancients to master single-celled organisms new ways of living. Among them was phagocytosis, which, according to one version, led to the emergence of a symbiotic organism, which later became the progenitor of the modern eukaryotic cell with all its characteristic organelles. The cell nucleus, structure and functions of some new structures made it possible to use oxygen in metabolism. The consequence of this was a fundamental change in the Earth's biosphere; the foundation was laid for the formation and development of multicellular organisms. Today, eukaryotic organisms, which include humans, dominate the planet, and there is no sign of changes in this regard.

Nuclear structures

The simplest syntactic models, which are the basis of speech activity, since they are used for various transformations according to the requirements of the context.

Dictionary-reference book linguistic terms. Ed. 2nd. - M.: Enlightenment. Rosenthal D. E., Telenkova M. A.. 1976 .

See what “nuclear structures” are in other dictionaries:

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nuclear fibrils- Thread-like intranuclear structures, which are fragments of the nuclear skeleton [Arefyev V.A., Lisovenko L.A. English-Russian explanatory dictionary of genetic terms 1995 407 pp.] Topics genetics EN nuclear fibrils ... Technical Translator's Guide

Transformations of atomic nuclei when interacting with elementary particles, γ quanta or with each other. To implement Ya.r. it is necessary to bring particles (two nuclei, a nucleus and a nucleon, etc.) closer to a distance Nuclear reactions 10 13 cm. Energy... ...

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Nuclear fibrils nuclear fibrils. Thread-like intranuclear structures that are fragments of the nuclear skeleton . (Source: “English-Russian Explanatory Dictionary of Genetic Terms.” Arefiev V.A., Lisovenko L.A., Moscow: Publishing House... ... Molecular biology and genetics. Dictionary.

nuclear proposals- the simplest syntactic structures of a given language, in which objects are designated by nouns, processes by verbs, and characteristics by adjectives and adverbs, from which surface structures are formed through a series of transformations... Explanatory translation dictionary

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Books

• Innovative activities in the nuclear industry (on the example of the strategy for the development of nuclear fuel cycles, including innovative ones). Book 1. Basic principles of innovation policy, A. V. Putilov, A. G. Vorobyov, M. N. Strikhanov. IN textbook the role and place of innovation in social development is revealed using the example of the nuclear industry; goals and objectives of national innovation policy. Tools reviewed...
• Introduction to the physics of the microworld. Physics of particles and nuclei, L. I. Sarycheva. This book presents the main characteristics of fundamental and elementary particles and the processes occurring with them in various types interactions. Modern...

NUCLEAR STRUCTURE OF AN ATOM

Alpha particles. In 1896, the French physicist Becquerel discovered the phenomenon of radioactivity. After this, rapid progress began in the study of the structure of the atom. This was primarily facilitated by the fact that in the hands of physicists there was very effective tool atomic structure research – α -particle. By using α -particles emitted by natural radioactive substances, were made most important discoveries: the nuclear structure of the atom has been established, the first nuclear reactions, the phenomenon of artificial radioactivity was discovered and, finally, a neutron was found, which played an important role both in explaining the structure atomic nucleus, and during the discovery of the process of fission of heavy nuclei.

Alpha particles are helium nuclei moving at high speed. Speed ​​measurements α- particles of natural emitters based on the deviation in the electric and magnetic fields gave a speed value of (1.5-2).10 7 m/s, which corresponds to kinetic energy 4.5-8 MeV (1 MeV=1.6.10 -13 J). Such particles move in a straight line in matter, quickly lose energy to ionize atoms, and after stopping they turn into neutral helium atoms.

Alpha particle scattering. Rutherford's experiments. By studying the passage of a collimated beam of alpha particles through a thin metal foil, English physicist Rutherford drew attention to the blurring of the image of a particle beam on the recorder - a photographic plate. Rutherford attributed this blurring to the scattering of alpha particles. A detailed study of the scattering of alpha particles has shown that in rare cases they are scattered at large angles, sometimes exceeding 90 0, which corresponds to the rejection of fast-moving particles in the opposite direction. Such cases of scattering cannot be explained within the framework of the Thompson model.

A heavy alpha particle in one collision can only be thrown back when interacting with a particle of greater mass, exceeding the mass of the alpha particle. Electrons cannot be such particles. In addition, backscattering implies strong deceleration of the alpha particle, i.e. the interaction energy must be on the order of the kinetic energy of the alpha particle. The energy of the electrostatic interaction of an alpha particle with a Thompson atom, which has a positive charge distributed in the volume or on the surface of an atom with a radius of 10 -8 cm and equal in units of elementary charge to approximately half atomic mass, much less than this value. The results of the experiment can be explained if the distance from the alpha particle to the center of the positive electric charge is about 10 -12 cm. This distance is 10,000 times less than the radius of the atom, and the radius of the positive charge should be even smaller. The assumption of a small volume of the scattering center is consistent with the very small number of cases of scattering at large angles.

To explain the results of his observations on the scattering of alpha particles, Rutherford proposed nuclear model of the atom. According to this model, at the center of the atom there is a nucleus that occupies a very small volume, contains almost the entire mass of the atom and carries a positive electric charge. The main volume of the atom is occupied by moving electrons, the number of which is equal to the number of elementary positive charges kernels, because the atom as a whole is neutral.

Alpha particle scattering theory. To substantiate the assumption about the nuclear structure of the atom and prove that the scattering of alpha particles occurs as a result of Coulomb interaction with the nucleus, Rutherford developed the theory of alpha particle scattering by point electric charges with large mass and obtained the relationship between the scattering angle θ and the number of particles scattered at an angle θ . If an alpha particle moves in the direction of a point charge Ze, Where Z- number elementary charges, and at the same time its initial trajectory is separated from the axis passing through the scattering center at a distance A(Fig. 1.1), then based on Coulomb’s law using the methods of classical mechanics it is possible to calculate the angle θ , to which the alpha particle will deviate due to electrostatic repulsion of like electric charges:

Where M And v – mass and speed of the alpha particle; 2 e– its charge; ε 0 – electrical constant equal to 8.85.10 -12 F/m.

Fig.1.1. Alpha particle scattering electric field atomic nucleus:

a) – scattering scheme in the plane of the particle trajectory; b) – ring from which scattering occurs at an angle θ ; c) – scattering scheme into a conical solid angle at an angle θ to the axis.

Particle fraction dn/n 0, having the impact parameter A, from the full number n 0 falling on the target is equal to the fraction of the elementary area 2πada in full area F cross section of a beam of alpha particles (Fig. 1.1, b). If in the square F there is not one, but N F scattering centers, then the corresponding fraction will increase by N F times and divided by one A, will be:

, (1.2)

Where N 1– the number of scattering centers per unit area of ​​the target.

Considering that dΩ=2π sinθ dθ, one can obtain the fraction of particles scattered per unit conical solid angle at an angle θ to the axis like:

(1.3)

Experimental testing completely confirmed the last dependence when alpha particles are scattered by matter. Strict implementation of the law 1/sin 4 indicates that only electric forces are responsible for scattering and that the geometric dimensions of the electric charges of both bodies are at least less than the shortest distance in the act of scattering r min. Distance r min the smaller the larger the scattering angle θ . At θ =π () it is the smallest and is determined by the condition , which corresponds to the case of converting the entire kinetic energy of an alpha particle into potential energy of repulsion of like charges.

Based on the results of processing the experimental results, based on various estimates of the nuclear charge at that time Z, Rutherford estimated the radius of the core to be on the order of 10 -12 cm.

Rutherford-Bohr atom. With the discovery of the atomic nucleus, the need arose to explain the stability of the atom. From the point of view of classical electrodynamics, a Rutherford atom cannot exist for a long time. Since unlike charges attract, electrons can only be at a certain distance from the nucleus if they move around the nucleus. However, motion along a closed trajectory is motion with acceleration, and an electric charge moving with acceleration radiates energy into the surrounding space. In a negligibly short time, any atom must radiate the energy of electron motion and decrease to the size of a nucleus.

The first stationary model of the atom was proposed by the Danish physicist Niels Bohr in 1913. Bohr connected the stability of atoms with the quantum nature of radiation. The energy quanta hypothesis, put forward by the German physicist Planck in 1900 to explain the radiation spectrum of a completely black body, argued that microscopic systems are capable of emitting energy only in certain portions - quanta with a frequency v, proportional to the quantum energy E:

Where h– universal Planck constant equal to 6.62.10 -24 J.s.

Bohr suggested that the energy of an atomic electron in the Coulomb field of the nucleus does not change continuously, but takes on a number of stable discrete values, which correspond to stationary electron orbits. When moving in such orbits, the electron does not radiate energy. Radiation of an atom occurs only when an electron moves from an orbit with a higher high value energy to another stationary orbit. This radiation is characterized by a single frequency value proportional to the energy difference between the orbits:

hv=E start - E end

The condition for the orbit to be stationary is the equality mechanical torque the momentum of an electron is an integer multiple h/2π:

mvr n = n ,

Where mv– modulus of electron momentum;

r n– radius n-th stationary orbit;

n– any integer.

The condition for quantizing circular orbits introduced by Bohr made it possible to calculate the spectrum of the hydrogen atom and calculate the spectroscopic Rydberg constant for the hydrogen atom. The level system of a one-electron atom and the radii of stationary orbits can be determined from the last relation and Coulomb’s law:

; (1.4)

Calculation using these formulas for n=1 And Z=1 gives the radius of the smallest stationary orbit of an electron in a hydrogen atom or the first Bohr radius:

. (1.6)

The motion of an electron along its orbit can be represented as a closed electricity and calculate the magnetic moment it creates. For the first orbit of hydrogen it is called the Bohr magneton and is equal to:

(1.7)

The magnetic moment is inversely proportional to the mass of the particle, but for particles of a given type, for example electrons, it has the meaning of unity. It is characteristic that just this unit is equal to own moment electron associated with its spin.

The nuclear model of an atom with electrons in stable orbits is called the Rutherford-Bohr planetary model. It does not lead to correct quantitative results when applied to atoms with more than one electron, but it is very convenient for the qualitative interpretation of atomic phenomena. Quantum mechanics provides an accurate theory of the atom.

Discrete nature of the microworld. The discovery of the atomic structure of matter turned out to be the first step towards discovering the discrete nature of the microcosm. Not only are the masses and electric charges of microbodies discrete, but also dynamic quantities, describing the states of microsystems, such as energy, angular momentum, are also discrete and characterized by abrupt changes in their numerical values.

1

The concept of the unity of material structures and ontological massless wave medium allows us to understand the nature of all types of interaction and the systemic organization of the structure of nucleons, nuclei and atoms. Neutrons play a key role in the formation and maintenance of nuclear stability, which is ensured by two boson exchange couplings between protons and neutrons. Alpha particles are the main “building blocks” in the structure. The structures of the nuclei, close in shape to spherical, are formed in accordance with the periods in periodic table DI. Mendeleev by the sequential addition of the n-p-n complex, alpha particles and neutrons. Reason radioactive decay atoms is a non-optimal structure of the nucleus: an excess of the number of protons or neutrons, asymmetry. The alpha structure of nuclei explains the reasons and energy balance all types of radioactive decay.

nucleon structure

alpha particles

"boson-exchange" forces

stability

radioactivity

1. Vernadsky V.I. Biosphere and noosphere. – M.: Rolf. 2002. – 576 p.

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3. Polyakov V.I. Exam for " Homo sapiens"(From ecology and macroecology... to the WORLD). – Saransk: publishing house Mordovian University, 2004. – 496 p.

4. Polyakov V.I. SPIRIT OF THE WORLD instead of chaos and vacuum (Physical structure of the Universe) // “Modern science-intensive technologies.” - 2004. No. 4. – P.17-20.

5. Polyakov V.I. Electron = positron?! //Modern high technology. – 2005. – No. 11. – pp. 71-72.

6. Polyakov V.I. Birth of matter // Basic Research 2007. No. 12. – P.46-58.

7. Polyakov V.I. Exam for “Homo sapiens – II”. From the concepts of natural science of the twentieth century - to natural understanding. – Publishing house “Academy of Natural Sciences”. – 2008. – 596 p.

8. Polyakov V.I. Why are protons stable and neutrons radioactive? // “Radioactivity and radioactive elements in the human environment”: IV International Conference, Tomsk, June 5-7, 2013. – Tomsk, 2013. – P. 415-419.

9. Polyakov V.I. Fundamentals of natural understanding of the structure of nucleons, nuclei, stability and radioactivity of atoms // Ibid. – pp. 419-423.

10. Polyakov V.I. Structures of atoms - orbital wave model // Advances in modern natural science. – 2014. No. 3. – P.108-114.

12. Physical quantities: Directory // A.P. Babichev, N.A. Babushkina, A.M. Bratkovsky and others; Ed. I.S. Grigorieva, E.Z. Melikhova. – M.: Energoatomizdat, 1991. – 1232 p.

Modern physics offers droplet, shell, generalized and other models to describe the structure of nuclei. The connection of nucleons in nuclei is explained by the binding energy caused by “special specific nuclear forces”. The properties of these forces (attraction, short-range action, charge independence, etc.) are accepted as an axiom. The question “why is this so?” arises for almost every thesis. “It is accepted (?) that these forces are the same for nucleons... (?). For light nuclei, the specific binding energy increases steeply, undergoing a number of jumps (?), then increases more slowly (?), and then gradually decreases.” “The most stable are the so-called “magic nuclei”, in which the number of protons or neutrons is equal to one of the magic numbers: 2, 8, 20, 28, 50, 82, 126...(?) Double magic nuclei are especially stable: 2He2, 8O8, 20Ca20, 20Ca28, 82Pb126" (the left and right indices correspond to the number of protons and neutrons in the nucleus, respectively). Why do “magic” nuclei exist, and the magic isotope 28Ni28 with a maximum specific binding energy of 8.7 MeV is short-lived
(T1/2 = 6.1 days)? “Nuclei are characterized by an almost constant binding energy and a constant density, independent of the number of nucleons” (?!). This means that binding energy does not characterize anything, just like table values mass defect (20Ca20 has less than 21Sc24, 28Ni30 has less than 27Co32 and 29Cu34, etc.). Physics admits that “the complex nature of nuclear forces and the difficulties of solving equations... have not made it possible to develop a single consistent theory of the atomic nucleus to date.” The science of the 20th century, built on the postulates of the theory of relativity, abolished logic and cause-and-effect relationships, and declared mathematical phantoms to be reality. Without knowing the structure of nuclei and atoms, scientists have created atomic bombs and are trying to simulate the Big Bang of the Universe in colliders...

The “Revolution in Natural Sciences of A. Einstein” replaced the works of dozens of outstanding scientists (Huygens, Hooke, Jung, Navier, Stokes, Hertz, Faraday, Maxwell, Lorentz, Thomson, Tesla, etc.) with equations of the “space-time continuum”, etc., who developed the theories electromagnetism and atomism in the “ether” medium. We should go back a century...

Purpose and method of work. A way out of the dead end of science is possible based on understanding the essence of the “ether” medium. IN AND. Vernadsky wrote: “Radiations from the NON-MATERIAL environment cover all available, all conceivable space... Around us, in ourselves, everywhere and everywhere, without interruption, forever changing, coinciding and colliding, there are radiations of different wavelengths - from waves whose length is calculated in ten millionths fractions of a millimeter, to long ones, measured in kilometers... The whole space is filled with them...". Everything material is formed by this ontological, non-material, wave environment and exists in interaction with it. “Ether” is not a gas or a chaos of vortices, but “Action that Orders Chaos - SPIRIT”. In the environment of SPIRIT from a single elementary particle - a masson (electron/positron), structures from nucleons, nuclei and atoms to the Universe are naturally and systematically organized.

The work develops a model of the structure of nuclei, which explains their properties, the reasons for the connection of nucleons in nuclei, special stability and radioactivity.

Structure and properties of nucleons

The model of nucleons accepted in physics is built from dozens of hypothetical particles with the fabulous name “quark” and fabulous differences, including: color, charm, strangeness, charm. This model is too complex, has no evidence and cannot even explain the mass of particles. A model of the structure of nucleons, explaining all their properties, was developed by I.V. Dmitriev (Samara) on the basis of his experimentally discovered principle of maximum configuration entropy (equality structural elements on the surface and in the volume of primary particles) and the thesis about the existence of particles only when rotating “along one, two or three of their own internal axes.” The nucleon is formed from 6 hexagonal structures of π+(-) mesons surrounding the plus-muon μ+, and their structure is built by selecting the number of balls: electrons and positrons of two types. Such a structure was substantiated on the basis of the interaction of material particles of masons and the environment of the Spirit in the work, and then refined and proven on the basis of constructing the structure of mesons in accordance with the fine structure constant
1/α = 2h(ε0/μ0)1/2/e2 = 137.036. Physicists W. Pauli and R. Feynman puzzled over the physical meaning of this constant, but in the SPIRIT medium it is obvious: only at a relative distance 1/α from the charge there is a wave interaction between matter and the medium.

Ras even number masons (me) in the muon structure should be 3/2α = 205.6, and the muon mass should be 206.768 me. In its structure of 207 masons, the central one determines the charge ±e and spin ±1/2, and 206 are mutually compensated. Pions, as postulated by I. Dmitriev, are formed from “biaxial” electrons and positrons (spin = 0, charge +/-, mass me). In the SPIRIT environment, bosons with a mass of 2/3 me should be formed as the first stage in the formation of matter from quanta of the background radiation of the Universe in the solar atmosphere. There should be 3/α = 411 such particles in a dense structure, and their mass should be 3/α · 2/3 me = 274 me, which corresponds to pi-mesons (mπ = 273.210 me). Their structure is similar to muons: the particle in the center determines the charge ± 2/3e and spin 0, and the 205 particles are mutually balanced.

The structure of the proton consisting of a central muon and 6 pions, taking into account the loss of mass due to the exchange (“nuclear”) coupling of 6 massons (coupling of the muon with pions) and 6 bosons (coupling between pions, 4 me) explains its mass.

Mr = 6mp + mm - 10me = 6·273.210 me+ +206.768 me - 10me =1836.028 me.

This value, with an accuracy of 0.007%, corresponds to the proton mass Мр = 1836.153me. The proton charge +e and spin ±1/2 are determined by the central masson+ in the central muon+. The proton model explains all its properties, including stability. In the SPIRIT environment, the interaction of material particles occurs as a result of the resonance of the associated “clouds” of the environment (the coincidence of shape and frequency). The proton is stable because it is protected from material particles and quanta by a shell of pions, which have a different wave field.

The mass of a proton is 1836.153 me, and that of a neutron is 1838.683 me. Compensation of the proton charge, by analogy with the hydrogen atom, will be provided by an electron in a wave orbit in its equatorial plane (“one axis of rotation”), and its “biaxial rotation” turns out to be “at home” in the pion cloud. Let's add 2 bosons in oppositely located neutron pions; they compensate orbital moment, and the mass of the neutron will be 1838.486 me. This structure explains the mass of the neutron (a difference of 0.01%), the absence of charge and, most importantly, the “nuclear” forces. The “extra” boson is weakly bound in the structure and provides an “exchange” connection, occupying a “vacancy” in the neighboring proton pion at the nuclear frequency, it displaces another boson returning to the neutron. The “extra” bosons in the neutron are its “two arms” that hold the nuclei together.

The neutron in the nuclei of elements ensures the stability of the nuclei, and itself is “saved” in the nucleus from decay (T1/2 = 11.7 min.), the cause of which is its “ weak spots": electron orbit and the presence of an "extra" boson in the "pion coat" of two of the six pions.

Scientists of the twentieth century came up with dozens of theories and hundreds of “elementary” particles, but could not explain the structure of atoms, and Nature needed only two similar particles to create two nucleons, and from them 92 elements and build the entire material WORLD!!!

Alpha structure of atomic nuclei

Isotopes of all elements most common in Nature have an even number of neutrons (with the exception of 4Be5 and 7N7). Of the 291 stable isotopes, 75% have an even number of neutrons and only 3% have even-odd nuclei. This indicates a preference for the bond of a proton with two neutrons, the absence of proton-proton bonds and the “charge independence of nuclear forces.” The nuclear framework is formed by neutron-proton bonds, where each neutron can hold 2 protons by exchanging two bosons (for example, 2He1). In heavy nuclei, the relative number of neutrons increases, strengthening the nuclear framework.

The presented arguments and the principle of systematic organization of matter in material environment allow us to propose a model of “block construction” of the structure of the nuclei of elements, in which the “block” is the nucleus of a helium atom - an alpha particle. Helium is the main element of cosmological nucleosynthesis, and in terms of abundance in the Universe it is the second element after hydrogen. Alpha particles are the optimal structure of tightly bound two pairs of nucleons. This is a very compact, tightly connected spherical structure, which can be geometrically represented as a sphere with a cube inscribed in it with nodes in opposite diagonals of 2 protons and 2 neutrons. Each neutron has two “nuclear exchange” bonds with two protons. The electromagnetic connection between the neutron and protons is provided by the orbital electron in its structure (confirmation: magnetic moments: μ(p) = 2.793 μN, μ(n) = -1.913 μN, where μN is the Bohr nuclear magneton).

The supposed “Coulomb” repulsion of protons does not contradict their approach. The explanation for this, as well as in the structures of muons from masons, lies in the understanding of “charge” as an integral property of the mass of a particle - the movement of the medium SPIRIT associated with the wave motion of the mass, expressed as a force in this medium (the unit of charge can be a coulomb2 - force multiplied by surface). The two types of +/- charges are left and right direction of rotation. When two protons approach in the equatorial plane, the movement of the “captured” medium will be opposite, and when approaching “from the poles” it occurs in the same direction, promoting convergence. The approach of particles is limited by the interaction of their “field” shells, corresponding to the “Compton” wavelength: λK(p) = 1.3214·10-15 m, and λK(n) = 1.3196·10-15 m. When the proton and neutron at such a distance the boson-exchange (“nuclear”) forces between them act.

The structures of nuclei from alpha particles are formed with a minimum volume and a shape close to spherical. The structure of alpha particles allows them to combine by breaking one n-p boson exchange bond and forming two n-p and p-n bonds with a neighboring alpha particle. For any number of protons in the nucleus, a single spherical field is formed, the intensity of which is the same as if the charge were concentrated in the center (Ostrogradsky-Gauss rule). The formation of a single nuclear field is confirmed by the orbital-wave structure of atoms, where all s, p, d, f orbits form spherical shells.

The construction of the nuclei of elements from alpha particles occurs systematically, sequentially in each period based on the nuclei of the previous element. In kernels with even number The proton bonds are balanced; the appearance of an additional proton in the structure of the next atom is not possible. In the nuclei of atoms after oxygen, the addition of a proton occurs according to the (n-p-n) scheme. A clear sequence of formation of structures in accordance with periods and series in the table D.I. Mendeleev - confirmation of the validity of the proposed model of nuclei and serves as confirmation of the thoughts of V.I. Vernadsky about the “succession of atoms”: “The process of the natural frailty of atoms inevitably and irresistibly occurs... Taking the history of any atom in cosmic time, we see that at certain intervals, immediately, in equal jumps, in the direction of the polar time vector, it passes into another atom, another chemical element". Schemes of the nuclei of the first periods of atoms are presented in table. 1.

Table 1

Estimated structure of nuclei (flat projection) of the main isotopes of stable atoms from alpha particles (α), protons (p) and neutrons (n): pAn

							nnααααααnn

	nnααααααnn		nnαααnnαααnn nnααnαααnααnn nαααnnαααn	nnααααααnn nααnnααnnααn nαααnnαααn

The next 5th and 6th periods of the elements can be modeled similarly, taking into account the fact that an increase in the number of protons will require an increase in the number of neutrons both in the inner framework of the nuclei and in the surface layer, according to the n-n scheme.

The presented visual flat projection of the structure of nuclei can be supplemented with an orbital diagram corresponding to the periods in the periodic table
(Table 2).

table 2

Nuclear shells of elements and periods in the table D.I. Mendeleev

Nuclear envelope - period	Start and end element in a series	Number of elements	n/p ratio
			Elementary	Finite
	55Cs78 -82Pb126 (83Bi126… 86Rn136)
	(87Fr136 - 92U146…).

Shells are built similar to the structure of an atom, where spherical shells of electron orbits in each period are formed at a larger radius than in the previous period.

Elements after 82Pb126 (83Bi126 T1/2 ≈1018 years) are not stable (given in parentheses in Table 2). The 41 alpha particles in the lead structure form an electrical charge, which requires the force of an additional 40-44 neutrons to maintain the stability of the nuclei. The ratio of the number of neutrons and protons n/p> (1.5÷1.6) is the stability limit for heavy nuclei. The half-lives of nuclei after 103 “elements” are seconds. These “elements” cannot preserve the structure of the nucleus and form the electron shell of the atom. It is hardly worth spending the money and time of scientists on their artificial production. There cannot be an “island of stability”!

The alpha structure model of nuclei explains the forces of interconnection, stability, and all properties of elements (completeness of the structure of inert gases, prevalence in nature and special stability of elements with a symmetrical structure: O, C, Si, Mg, Ca, similarity to Cu, Ag, Au...) .

Reasons for “non-spontaneous” decay

The structures of radioactive isotopes are not symmetrical and contain an unbalanced n-p pair. The half-life of isotopes is shorter, the more their structure differs from the optimal one. The radioactivity of isotopes with a large number of protons is explained by the fact that the “exchange” forces of neutrons are not capable of maintaining their total charge, and the decay of isotopes with an excess of neutrons is explained by their excess for the optimal structure. The alpha structure of nuclei allows us to explain the causes of all types of radioactive decay.

Alpha decay. In nuclear physics, “according to modern ideas, alpha particles are formed at the moment of radioactive decay when two protons and two neutrons moving inside the nucleus meet... the escape of an alpha particle from the nucleus is possible due to the tunneling effect through a potential barrier with a height of at least 8.8 MeV.” Everything happens by chance: movement, meeting, formation, gaining energy and flying through a certain barrier. In nuclei with an alpha structure there are no barriers to escape. When the strength of the total charge of all protons exceeds the boson-exchange forces restraining all neutrons, the nucleus throws off the alpha particle, the least bound in the structure, and “rejuvenates” by 2 charges. The possibility of alpha decay depends on the structure of the nuclei. It appears at 31 alpha particles in the 62Sm84 nucleus (n/p = 1.31), and becomes necessary from 84Po (n/p = 1.48).

β+ decay. In nuclear physics, “the β+-decay process proceeds as if one of the protons of the nucleus turned into a neutron, emitting a positron and a neutrino: 11p→ 01n + +10e + 00νe... Since the mass of a proton is less than that of a neutron, then Such reactions cannot be observed for a free proton. However, for a proton bound in the nucleus, due to the nuclear interaction of particles, these reactions turn out to be energetically possible." Physics replaced the explanation of the reaction process, the appearance of a positron in the nucleus and the increase in mass by 2.5 me for the transformation of a proton into a neutron with the postulate: “the process is possible.” This possibility is explained by the alpha structure. Let's consider the classical decay scheme: 15Р15 → 14Si16 + +10e + 00νe. In accordance with Table 1, the structure of the stable isotope 15Р16 (7α-npn). Isotope structure
15P15 - (7α-np), but the (n-p) bond in the structure is weak, so the half-life is 2.5 minutes. The decay scheme can be presented in several stages. A weakly bound proton is pushed out by the charge of the nucleus, but “grabs” the neutron of the alpha particle and destroys it with the release of 4 bond bosons. “Biaxial” bosons cannot exist in the SPIRIT environment and are transformed into “triaxial” masons with different moments (+ and -; electron and positron) with the emission of neutrinos and antineutrinos according to the schemes
β-: (e--- + e+++ → e- -++ + ν0-) and β+: (e--- + e+++ → e+ --+ + ν0+). The positron is pushed out of the nucleus, and the electron in orbit around the former proton compensates for its charge, turning it into a neutron. Estimated reaction scheme: (7α-np) → (6α- n-p-n-р-n-p + 2е--- + 2e+++) → ((6 α) + (npnp) + n + (p-e-)) + e+ + ν0- + ν0+ → (7 α -nn) + e+ + ν0- + ν0+ . The diagram explains the cause and process of decay, the change in the mass of particles and assumes the emission of 2 pulses: neutrinos and antineutrinos.

β-decay. “Since the electron does not fly out of the nucleus and does not escape from the shell of the atom, it was assumed that the β-electron is born as a result of processes occurring inside the nucleus...”. There is an explanation! This process is typical for nuclei that have a greater number of neutrons in their structure than stable isotopes of this element. The structure of the nucleus of the next isotope after the nucleus with the formed even-even structure grows in an n-p-n “block”, and the isotope next in mass contains another “very useful” neutron. A neutron can quickly “dump” an orbital electron to become a proton and form an alpha structure: npn + (n→p) = npnp = α. The electron and antineutrino carry away excess mass and energy, and the charge of the nucleus increases by one.

ε-capture. When there are not enough neutrons for a stable structure, the excess charge of protons attracts and captures an electron from one of the inner shells of the atom, emitting a neutrino. A proton in the nucleus turns into a neutron.

Conclusion

The presented model of the alpha structure of element nuclei makes it possible to explain the patterns of nuclear formation, their stability, causes, stages and energy balance of all types of radioactive decay. The structures of protons, neutrons, nuclei and atoms of elements, confirmed by their correspondence to universal constants, which are the physical characteristics of the SPIRIT environment, explain all properties and all interactions. Modern nuclear and atomic physics are not capable of this. A revision of basic concepts is necessary: ​​from postulates to understanding.

Bibliographic link

Polyakov V.I. STRUCTURE OF ATOMIC NUCLEI AND CAUSES OF RADIOACTIVITY // Advances in modern natural science. – 2014. – No. 5-2. – pp. 125-130;
URL: http://natural-sciences.ru/ru/article/view?id=33938 (access date: 02/27/2019). We bring to your attention magazines published by the publishing house "Academy of Natural Sciences"