How the genetic code affects character and destiny. DNA and genes Hereditary information and genetic code

On the right is the largest human DNA helix built from people on the beach in Varna (Bulgaria), which was included in the Guinness Book of Records on April 23, 2016

Deoxyribonucleic acid. General information

DNA (deoxyribonucleic acid) is a kind of blueprint of life, a complex code that contains data on hereditary information. This complex macromolecule is capable of storing and transmitting hereditary genetic information from generation to generation. DNA determines such properties of any living organism as heredity and variability. The information encoded in it determines the entire development program of any living organism. Genetically embedded factors predetermine the entire course of life of both a person and any other organism. Artificial or natural influence of the external environment can only slightly affect the overall severity of individual genetic traits or affect the development of programmed processes.

Deoxyribonucleic acid(DNA) is a macromolecule (one of the three main ones, the other two are RNA and proteins), which provides storage, transmission from generation to generation and implementation of the genetic program for the development and functioning of living organisms. DNA contains information about the structure of various types of RNA and proteins.

In eukaryotic cells (animals, plants, and fungi), DNA is found in the cell nucleus as part of chromosomes, as well as in some cell organelles (mitochondria and plastids). In the cells of prokaryotic organisms (bacteria and archaea), a circular or linear DNA molecule, the so-called nucleoid, is attached from the inside to the cell membrane. They and lower eukaryotes (for example, yeast) also have small autonomous, mostly circular DNA molecules called plasmids.

From a chemical point of view, DNA is a long polymeric molecule consisting of repeating blocks - nucleotides. Each nucleotide is made up of a nitrogenous base, a sugar (deoxyribose), and a phosphate group. The bonds between nucleotides in a chain are formed by deoxyribose ( FROM) and phosphate ( F) groups (phosphodiester bonds).

Rice. 2. Nuclertide consists of a nitrogenous base, sugar (deoxyribose) and a phosphate group

In the overwhelming majority of cases (except for some viruses containing single-stranded DNA), the DNA macromolecule consists of two chains oriented by nitrogenous bases to each other. This double-stranded molecule is twisted in a helix.

There are four types of nitrogenous bases found in DNA (adenine, guanine, thymine, and cytosine). The nitrogenous bases of one of the chains are connected to the nitrogenous bases of the other chain by hydrogen bonds according to the principle of complementarity: adenine combines only with thymine ( A-T), guanine - only with cytosine ( G-C). It is these pairs that make up the "rungs" of the helical "ladder" of DNA (see: Fig. 2, 3 and 4).

Rice. 2. Nitrogenous bases

The sequence of nucleotides allows you to "encode" information about various types of RNA, the most important of which are information or template (mRNA), ribosomal (rRNA) and transport (tRNA). All these types of RNA are synthesized on the DNA template by copying the DNA sequence into the RNA sequence synthesized during transcription and take part in protein biosynthesis (translation process). In addition to coding sequences, cell DNA contains sequences that perform regulatory and structural functions.

Rice. 3. DNA replication

The location of the basic combinations of DNA chemical compounds and the quantitative ratios between these combinations provide encoding of hereditary information.

Education new DNA (replication)

1. The process of replication: the unwinding of the DNA double helix - the synthesis of complementary strands by DNA polymerase - the formation of two DNA molecules from one.
2. The double helix "unzips" into two branches when enzymes break the bond between the base pairs of chemical compounds.
3. Each branch is a new DNA element. New base pairs are connected in the same sequence as in the parent branch.

Upon completion of the duplication, two independent helices are formed, created from the chemical compounds of the parent DNA and having the same genetic code with it. In this way, DNA is able to rip through information from cell to cell.

More detailed information:

STRUCTURE OF NUCLEIC ACIDS

Rice. 4 . Nitrogenous bases: adenine, guanine, cytosine, thymine

Deoxyribonucleic acid(DNA) refers to nucleic acids. Nucleic acids is a class of irregular biopolymers whose monomers are nucleotides.

NUCLEOTIDES consist of nitrogenous base, connected to a five-carbon carbohydrate (pentose) - deoxyribose(in the case of DNA) or ribose(in the case of RNA), which combines with a phosphoric acid residue (H 2 PO 3 -).

Nitrogenous bases There are two types: pyrimidine bases - uracil (only in RNA), cytosine and thymine, purine bases - adenine and guanine.

Rice. Fig. 5. The structure of nucleotides (left), the location of the nucleotide in DNA (bottom) and the types of nitrogenous bases (right): pyrimidine and purine

The carbon atoms in a pentose molecule are numbered from 1 to 5. Phosphate combines with the third and fifth carbon atoms. This is how nucleic acids are linked together to form a chain of nucleic acids. Thus, we can isolate the 3' and 5' ends of the DNA strand:

Rice. 6. Isolation of the 3' and 5' ends of the DNA strand

Two strands of DNA form double helix. These chains in a spiral are oriented in opposite directions. In different strands of DNA, nitrogenous bases are connected to each other by means of hydrogen bonds. Adenine always combines with thymine, and cytosine always combines with guanine. It is called complementarity rule(cm. principle of complementarity).

Complementarity rule:

A-T G-C

For example, if we are given a DNA strand that has the sequence

3'-ATGTCCTAGCTGCTCG - 5',

then the second chain will be complementary to it and directed in the opposite direction - from the 5'-end to the 3'-end:

5'- TACAGGATCGACGAGC- 3'.

Rice. 7. The direction of the chains of the DNA molecule and the connection of nitrogenous bases using hydrogen bonds

DNA REPLICATION

DNA replication is the process of doubling a DNA molecule by template synthesis. In most cases of natural DNA replicationprimerfor DNA synthesis is short snippet (created again). Such a ribonucleotide primer is created by the enzyme primase (DNA primase in prokaryotes, DNA polymerase in eukaryotes), and is subsequently replaced by deoxyribonucleotide polymerase, which normally performs repair functions (correcting chemical damage and breaks in the DNA molecule).

Replication occurs in a semi-conservative manner. This means that the double helix of DNA unwinds and a new chain is completed on each of its chains according to the principle of complementarity. The daughter DNA molecule thus contains one strand from the parent molecule and one newly synthesized. Replication occurs in the 3' to 5' direction of the parent strand.

Rice. 8. Replication (doubling) of the DNA molecule

DNA synthesis- this is not such a complicated process as it might seem at first glance. If you think about it, then first you need to figure out what synthesis is. It is the process of bringing something together. The formation of a new DNA molecule takes place in several stages:

1) DNA topoisomerase, located in front of the replication fork, cuts DNA in order to facilitate its unwinding and unwinding.
2) DNA helicase, following topoisomerase, affects the process of "unwinding" the DNA helix.
3) DNA-binding proteins carry out the binding of DNA strands, and also carry out their stabilization, preventing them from sticking to each other.
4) DNA polymerase δ(delta) , coordinated with the speed of movement of the replication fork, performs the synthesisleadingchains subsidiary DNA in the direction 5" → 3" on the matrix maternal strands of DNA in the direction from its 3" end to the 5" end (speed up to 100 base pairs per second). These events on this maternal strands of DNA are limited.

Rice. 9. Schematic representation of the DNA replication process: (1) Lagging strand (lag strand), (2) Leading strand (leading strand), (3) DNA polymerase α (Polα), (4) DNA ligase, (5) RNA -primer, (6) Primase, (7) Okazaki fragment, (8) DNA polymerase δ (Polδ ), (9) Helicase, (10) Single-stranded DNA-binding proteins, (11) Topoisomerase.

The synthesis of the lagging daughter DNA strand is described below (see below). scheme replication fork and function of replication enzymes)

For more information on DNA replication, see

5) Immediately after the unwinding and stabilization of another strand of the parent molecule, it joinsDNA polymerase α(alpha)and in the direction 5 "→3" synthesizes a primer (RNA primer) - an RNA sequence on a DNA template with a length of 10 to 200 nucleotides. After that, the enzymeremoved from the DNA strand.

Instead of DNA polymeraseα attached to the 3" end of the primer DNA polymeraseε .

6) DNA polymeraseε (epsilon) as if continues to lengthen the primer, but as a substrate embedsdeoxyribonucleotides(in the amount of 150-200 nucleotides). As a result, a solid thread is formed from two parts -RNA(i.e. primer) and DNA. DNA polymerase εworks until it encounters the primer of the previousfragment Okazaki(synthesized a little earlier). This enzyme is then removed from the chain.

7) DNA polymerase β(beta) stands in place ofDNA polymerases ε,moves in the same direction (5" → 3") and removes primer ribonucleotides while inserting deoxyribonucleotides in their place. The enzyme works until the complete removal of the primer, i.e. until a deoxyribonucleotide (even more previously synthesizedDNA polymerase ε). The enzyme is not able to link the result of its work and the DNA in front, so it leaves the chain.

As a result, a fragment of the daughter DNA "lies" on the matrix of the mother thread. It is calledfragment of Okazaki.

8) DNA ligase ligates two adjacent fragments Okazaki , i.e. 5 "-end of the segment, synthesizedDNA polymerase ε,and 3" chain end built-inDNA polymeraseβ .

STRUCTURE OF RNA

Ribonucleic acid(RNA) is one of the three main macromolecules (the other two are DNA and proteins) that are found in the cells of all living organisms.

Just like DNA, RNA is made up of a long chain in which each link is called nucleotide. Each nucleotide is made up of a nitrogenous base, a ribose sugar, and a phosphate group. However, unlike DNA, RNA usually has one rather than two strands. Pentose in RNA is represented by ribose, not deoxyribose (ribose has an additional hydroxyl group on the second carbohydrate atom). Finally, DNA differs from RNA in the composition of nitrogenous bases: instead of thymine ( T) uracil is present in RNA ( U) , which is also complementary to adenine.

The sequence of nucleotides allows RNA to encode genetic information. All cellular organisms use RNA (mRNA) to program protein synthesis.

Cellular RNAs are formed in a process called transcription , that is, the synthesis of RNA on a DNA template, carried out by special enzymes - RNA polymerases.

Messenger RNAs (mRNAs) then take part in a process called broadcast, those. protein synthesis on the mRNA template with the participation of ribosomes. Other RNAs undergo chemical modifications after transcription, and after the formation of secondary and tertiary structures, they perform functions that depend on the type of RNA.

Rice. 10. The difference between DNA and RNA in terms of the nitrogenous base: instead of thymine (T), RNA contains uracil (U), which is also complementary to adenine.

TRANSCRIPTION

This is the process of RNA synthesis on a DNA template. DNA unwinds at one of the sites. One of the chains contains information that needs to be copied onto the RNA molecule - this chain is called coding. The second strand of DNA, which is complementary to the coding strand, is called the template strand. In the process of transcription on the template chain in the 3'-5' direction (along the DNA chain), an RNA chain complementary to it is synthesized. Thus, an RNA copy of the coding strand is created.

Rice. 11. Schematic representation of transcription

For example, if we are given the sequence of the coding strand

3'-ATGTCCTAGCTGCTCG - 5',

then, according to the rule of complementarity, the matrix chain will carry the sequence

5'- TACAGGATCGACGAGC- 3',

and the RNA synthesized from it is the sequence

BROADCAST

Consider the mechanism protein synthesis on the RNA matrix, as well as the genetic code and its properties. Also, for clarity, at the link below, we recommend watching a short video about the processes of transcription and translation occurring in a living cell:

Rice. 12. Process of protein synthesis: DNA codes for RNA, RNA codes for protein

GENETIC CODE

Genetic code- a method of encoding the amino acid sequence of proteins using a sequence of nucleotides. Each amino acid is encoded by a sequence of three nucleotides - a codon or a triplet.

Genetic code common to most pro- and eukaryotes. The table lists all 64 codons and lists the corresponding amino acids. The base order is from the 5" to the 3" end of the mRNA.

Table 1. Standard genetic code

1st the foundation nie	2nd base								3rd the foundation nie
	U		C		A		G
U	U U U	(Phe/F)	U C U	(Ser/S)	U A U	(Tyr/Y)	U G U	(Cys/C)	U
	U U C		U C C		U A C		U G C		C
	U U A	(Leu/L)	U C A		U A A	Stop codon**	U G A	Stop codon**	A
	U U G		U C G		U A G	Stop codon**	U G G	(Trp/W)	G
C	C U U		C C U	(Pro/P)	C A U	(His/H)	C G U	(Arg/R)	U
	C U C		C C C		C A C		C G C		C
	C U A		C C A		C A A	(Gln/Q)	CGA		A
	C U G		C C G		C A G		C G G		G
A	A U U	(Ile/I)	A C U	(Thr/T)	A A U	(Asn/N)	A G U	(Ser/S)	U
	A U C		A C C		A A C		A G C		C
	A U A		A C A		A A A	(Lys/K)	A G A		A
	A U G	(Met/M)	A C G		A A G		A G G		G
G	G U U	(Val/V)	G C U	(Ala/A)	G A U	(Asp/D)	G G U	(Gly/G)	U
	G U C		G C C		G A C		G G C		C
	G U A		G C A		G A A	(Glu/E)	G G A		A
	G U G		G C G		G A G		G G G		G

Among the triplets, there are 4 special sequences that act as "punctuation marks":

• *Triplet AUG, also encoding methionine, is called start codon. This codon begins the synthesis of a protein molecule. Thus, during protein synthesis, the first amino acid in the sequence will always be methionine.

• **Triplets UAA, UAG And UGA called stop codons and do not code for any amino acids. At these sequences, protein synthesis stops.

Properties of the genetic code

1. Tripletity. Each amino acid is encoded by a sequence of three nucleotides - a triplet or codon.

2. Continuity. There are no additional nucleotides between the triplets, information is read continuously.

3. Non-overlapping. One nucleotide cannot be part of two triplets at the same time.

4. Uniqueness. One codon can code for only one amino acid.

5. Degeneracy. One amino acid can be encoded by several different codons.

6. Versatility. The genetic code is the same for all living organisms.

Example. We are given the sequence of the coding strand:

3’- CCGATTGCACGTCGATCGTATA- 5’.

The matrix chain will have the sequence:

5’- GGCTAACGTGCAGCTAGCATAT- 3’.

Now we “synthesize” informational RNA from this chain:

3’- CCGAUUGCACGUCGAUCGUAUA- 5’.

Protein synthesis goes in the direction 5' → 3', therefore, we need to flip the sequence in order to "read" the genetic code:

5’- AUAUGCUAGCUGCACGUUAGCC- 3’.

Now find the start codon AUG:

5’- AU AUG CUAGCUGCACGUUAGCC- 3’.

Divide the sequence into triplets:

sounds like this: information from DNA is transferred to RNA (transcription), from RNA to protein (translation). DNA can also be duplicated by replication, and the process of reverse transcription is also possible, when DNA is synthesized from an RNA template, but such a process is mainly characteristic of viruses.

Rice. 13. Central dogma of molecular biology

GENOM: GENES AND CHROMOSOMES

(general concepts)

Genome - the totality of all the genes of an organism; its complete chromosome set.

The term "genome" was proposed by G. Winkler in 1920 to describe the totality of genes contained in the haploid set of chromosomes of organisms of the same biological species. The original meaning of this term indicated that the concept of the genome, in contrast to the genotype, is a genetic characteristic of the species as a whole, and not of an individual. With the development of molecular genetics, the meaning of this term has changed. It is known that DNA, which is the carrier of genetic information in most organisms and, therefore, forms the basis of the genome, includes not only genes in the modern sense of the word. Most of the DNA of eukaryotic cells is represented by non-coding (“redundant”) nucleotide sequences that do not contain information about proteins and nucleic acids. Thus, the main part of the genome of any organism is the entire DNA of its haploid set of chromosomes.

Genes are segments of DNA molecules that code for polypeptides and RNA molecules.

Over the past century, our understanding of genes has changed significantly. Previously, a genome was a region of a chromosome that encodes or determines one trait or phenotypic(visible) property, such as eye color.

In 1940, George Beadle and Edward Tatham proposed a molecular definition of a gene. Scientists processed fungus spores Neurospora crassa X-rays and other agents that cause changes in the DNA sequence ( mutations), and found mutant strains of the fungus that lost some specific enzymes, which in some cases led to disruption of the entire metabolic pathway. Beadle and Tatham came to the conclusion that a gene is a section of genetic material that defines or codes for a single enzyme. This is how the hypothesis "one gene, one enzyme". This concept was later extended to the definition "one gene - one polypeptide", since many genes encode proteins that are not enzymes, and a polypeptide can be a subunit of a complex protein complex.

On fig. 14 shows a diagram of how DNA triplets determine a polypeptide, the amino acid sequence of a protein, mediated by mRNA. One of the DNA strands plays the role of a template for the synthesis of mRNA, the nucleotide triplets (codons) of which are complementary to the DNA triplets. In some bacteria and many eukaryotes, coding sequences are interrupted by non-coding regions (called introns).

Modern biochemical definition of a gene even more specifically. Genes are all sections of DNA that encode the primary sequence of end products, which include polypeptides or RNA that have a structural or catalytic function.

Along with genes, DNA also contains other sequences that perform an exclusively regulatory function. Regulatory sequences may mark the beginning or end of genes, affect transcription, or indicate the site of initiation of replication or recombination. Some genes can be expressed in different ways, with the same piece of DNA serving as a template for the formation of different products.

We can roughly calculate minimum gene size coding for the intermediate protein. Each amino acid in a polypeptide chain is encoded by a sequence of three nucleotides; the sequences of these triplets (codons) correspond to the chain of amino acids in the polypeptide encoded by the given gene. A polypeptide chain of 350 amino acid residues (medium length chain) corresponds to a sequence of 1050 bp. ( bp). However, many eukaryotic genes and some prokaryotic genes are interrupted by DNA segments that do not carry information about the protein, and therefore turn out to be much longer than a simple calculation shows.

How many genes are on one chromosome?

Rice. 15. View of chromosomes in prokaryotic (left) and eukaryotic cells. Histones are a broad class of nuclear proteins that perform two main functions: they are involved in the packaging of DNA strands in the nucleus and in the epigenetic regulation of nuclear processes such as transcription, replication, and repair.

The DNA of prokaryotes is more simple: their cells do not have a nucleus, so the DNA is located directly in the cytoplasm in the form of a nucleoid.

As you know, bacterial cells have a chromosome in the form of a DNA strand, packed into a compact structure - a nucleoid. prokaryotic chromosome Escherichia coli, whose genome is completely decoded, is a circular DNA molecule (in fact, this is not a regular circle, but rather a loop without beginning and end), consisting of 4,639,675 bp. This sequence contains approximately 4300 protein genes and another 157 genes for stable RNA molecules. IN human genome approximately 3.1 billion base pairs corresponding to almost 29,000 genes located on 24 different chromosomes.

Prokaryotes (Bacteria).

Bacterium E. coli has one double-stranded circular DNA molecule. It consists of 4,639,675 b.p. and reaches a length of approximately 1.7 mm, which exceeds the length of the cell itself E. coli about 850 times. In addition to the large circular chromosome as part of the nucleoid, many bacteria contain one or more small circular DNA molecules that are freely located in the cytosol. These extrachromosomal elements are called plasmids(Fig. 16).

Most plasmids consist of only a few thousand base pairs, some contain more than 10,000 bp. They carry genetic information and replicate to form daughter plasmids, which enter the daughter cells during the division of the parent cell. Plasmids are found not only in bacteria, but also in yeast and other fungi. In many cases, plasmids offer no advantage to the host cells and their only job is to reproduce independently. However, some plasmids carry genes useful to the host. For example, genes contained in plasmids can confer resistance to antibacterial agents in bacterial cells. Plasmids carrying the β-lactamase gene confer resistance to β-lactam antibiotics such as penicillin and amoxicillin. Plasmids can pass from antibiotic-resistant cells to other cells of the same or different bacterial species, causing those cells to also become resistant. Intensive use of antibiotics is a powerful selective factor that promotes the spread of plasmids encoding antibiotic resistance (as well as transposons that encode similar genes) among pathogenic bacteria, and leads to the emergence of bacterial strains with resistance to several antibiotics. Doctors are beginning to understand the dangers of widespread use of antibiotics and prescribe them only when absolutely necessary. For similar reasons, the widespread use of antibiotics for the treatment of farm animals is limited.

See also: Ravin N.V., Shestakov S.V. Prokaryotic genome // Vavilov Journal of Genetics and Breeding, 2013. V. 17. No. 4/2. pp. 972-984.

Eukaryotes.

Table 2. DNA, genes and chromosomes of some organisms

	shared DNA, b.s.	Number of chromosomes*	Approximate number of genes
Escherichia coli(bacterium)	4 639 675		4 435
Saccharomyces cerevisiae(yeast)	12 080 000	16**	5 860
Caenorhabditis elegans(nematode)	90 269 800	12***	23 000
Arabidopsis thaliana(plant)	119 186 200		33 000
Drosophila melanogaster(fruit fly)	120 367 260		20 000
Oryza sativa(rice)	480 000 000		57 000
Mus muscle(mouse)	2 634 266 500		27 000
Homo sapiens(human)	3 070 128 600		29 000

Note. Information is constantly updated; For more up-to-date information, refer to individual genomic project websites.

* For all eukaryotes, except yeast, the diploid set of chromosomes is given. diploid kit chromosomes (from Greek diploos - double and eidos - view) - double set of chromosomes(2n), each of which has a homology to itself.
**Haploid set. Wild strains of yeast typically have eight (octaploid) or more sets of these chromosomes.
***For females with two X chromosomes. Males have an X chromosome, but no Y, i.e. only 11 chromosomes.

A yeast cell, one of the smallest eukaryotes, has 2.6 times more DNA than a cell E. coli(Table 2). fruit fly cells Drosophila, a classic object of genetic research, contain 35 times more DNA, and human cells contain about 700 times more DNA than cells E. coli. Many plants and amphibians contain even more DNA. The genetic material of eukaryotic cells is organized in the form of chromosomes. Diploid set of chromosomes (2 n) depends on the type of organism (Table 2).

For example, in a human somatic cell there are 46 chromosomes ( rice. 17). Each chromosome in a eukaryotic cell, as shown in Fig. 17, but, contains one very large double-stranded DNA molecule. Twenty-four human chromosomes (22 paired chromosomes and two sex chromosomes X and Y) differ in length by more than 25 times. Each eukaryotic chromosome contains a specific set of genes.

Rice. 17. eukaryotic chromosomes.but- a pair of connected and condensed sister chromatids from the human chromosome. In this form, eukaryotic chromosomes remain after replication and in metaphase during mitosis. b- a complete set of chromosomes from a leukocyte of one of the authors of the book. Each normal human somatic cell contains 46 chromosomes.

The size and function of DNA as a matrix for storing and transmitting hereditary material explains the presence of special structural elements in the organization of this molecule. In higher organisms, DNA is distributed between chromosomes.

The set of DNA (chromosomes) of an organism is called the genome. Chromosomes are located in the cell nucleus and form a structure called chromatin. Chromatin is a complex of DNA and basic proteins (histones) in a 1:1 ratio. The length of DNA is usually measured by the number of pairs of complementary nucleotides (bp). For example, the 3rd human chromosomecentury is a DNA molecule with a size of 160 million bp. has a length of approximately 1 mm, therefore, a linearized molecule of the 3rd human chromosome would be 5 mm in length, and the DNA of all 23 chromosomes (~ 3 * 10 9 bp, MR = 1.8 * 10 12) of a haploid cell - egg or sperm cell - in a linearized form would be 1 m. With the exception of germ cells, all cells of the human body (there are about 1013 of them) contain a double set of chromosomes. During cell division, all 46 DNA molecules replicate and reorganize into 46 chromosomes.

If you connect the DNA molecules of the human genome (22 chromosomes and chromosomes X and Y or X and X), you get a sequence about one meter long. Note: In all mammals and other heterogametic male organisms, females have two X chromosomes (XX) and males have one X chromosome and one Y chromosome (XY).

Most human cells, so the total DNA length of such cells is about 2m. An adult human has about 10 14 cells, so the total length of all DNA molecules is 2・10 11 km. For comparison, the circumference of the Earth is 4・10 4 km, and the distance from the Earth to the Sun is 1.5・10 8 km. That's how amazingly compactly packaged DNA is in our cells!

In eukaryotic cells, there are other organelles containing DNA - these are mitochondria and chloroplasts. Many hypotheses have been put forward regarding the origin of mitochondrial and chloroplast DNA. The generally accepted point of view today is that they are the rudiments of the chromosomes of ancient bacteria that penetrated into the cytoplasm of the host cells and became the precursors of these organelles. Mitochondrial DNA codes for mitochondrial tRNA and rRNA, as well as several mitochondrial proteins. More than 95% of mitochondrial proteins are encoded by nuclear DNA.

STRUCTURE OF GENES

Consider the structure of the gene in prokaryotes and eukaryotes, their similarities and differences. Despite the fact that a gene is a section of DNA encoding only one protein or RNA, in addition to the direct coding part, it also includes regulatory and other structural elements that have a different structure in prokaryotes and eukaryotes.

coding sequence- the main structural and functional unit of the gene, it is in it that the triplets of nucleotides encodingamino acid sequence. It starts with a start codon and ends with a stop codon.

Before and after the coding sequence are untranslated 5' and 3' sequences. They perform regulatory and auxiliary functions, for example, ensure the landing of the ribosome on mRNA.

Untranslated and coding sequences constitute a transcription unit - a transcribed DNA region, that is, a DNA region from which mRNA is synthesized.

Terminator A non-transcribed region of DNA at the end of a gene where RNA synthesis stops.

At the beginning of the gene is regulatory area, which includes promoter And operator.

promoter- the sequence with which the polymerase binds during transcription initiation. Operator- this is the area to which special proteins can bind - repressors, which can reduce the activity of RNA synthesis from this gene - in other words, reduce it expression.

The structure of genes in prokaryotes

The general plan for the structure of genes in prokaryotes and eukaryotes does not differ - both of them contain a regulatory region with a promoter and operator, a transcription unit with coding and non-translated sequences, and a terminator. However, the organization of genes in prokaryotes and eukaryotes is different.

Rice. 18. Scheme of the structure of the gene in prokaryotes (bacteria) -the image is enlarged

At the beginning and at the end of the operon, there are common regulatory regions for several structural genes. From the transcribed region of the operon, one mRNA molecule is read, which contains several coding sequences, each of which has its own start and stop codon. From each of these areasone protein is synthesized. In this way, Several protein molecules are synthesized from one i-RNA molecule.

Prokaryotes are characterized by the combination of several genes into a single functional unit - operon. The work of the operon can be regulated by other genes, which can be noticeably removed from the operon itself - regulators. The protein translated from this gene is called repressor. It binds to the operator of the operon, regulating the expression of all the genes contained in it at once.

Prokaryotes are also characterized by the phenomenon transcription and translation conjugations.

Rice. 19 The phenomenon of conjugation of transcription and translation in prokaryotes - the image is enlarged

This pairing does not occur in eukaryotes due to the presence of a nuclear envelope that separates the cytoplasm, where translation occurs, from the genetic material, on which transcription occurs. In prokaryotes, during the synthesis of RNA on a DNA template, a ribosome can immediately bind to the synthesized RNA molecule. Thus, translation begins even before transcription is complete. Moreover, several ribosomes can simultaneously bind to one RNA molecule, synthesizing several molecules of one protein at once.

The structure of genes in eukaryotes

The genes and chromosomes of eukaryotes are very complexly organized.

Bacteria of many species have only one chromosome, and in almost all cases there is one copy of each gene on each chromosome. Only a few genes, such as rRNA genes, are contained in multiple copies. Genes and regulatory sequences make up almost the entire genome of prokaryotes. Moreover, almost every gene strictly corresponds to the amino acid sequence (or RNA sequence) that it encodes (Fig. 14).

The structural and functional organization of eukaryotic genes is much more complex. The study of eukaryotic chromosomes, and later the sequencing of complete eukaryotic genome sequences, has brought many surprises. Many, if not most, eukaryotic genes have an interesting feature: their nucleotide sequences contain one or more DNA regions that do not encode the amino acid sequence of the polypeptide product. Such non-translated inserts disrupt the direct correspondence between the nucleotide sequence of the gene and the amino acid sequence of the encoded polypeptide. These untranslated segments in the genes are called introns, or built-in sequences, and the coding segments are exons. In prokaryotes, only a few genes contain introns.

So, in eukaryotes, there is practically no combination of genes into operons, and the coding sequence of a eukaryotic gene is most often divided into translated regions. - exons, and untranslated sections - introns.

In most cases, the function of introns has not been established. In general, only about 1.5% of human DNA is "coding", that is, it carries information about proteins or RNA. However, taking into account large introns, it turns out that 30% of human DNA consists of genes. Since genes make up a relatively small proportion of the human genome, a significant amount of DNA remains unaccounted for.

Rice. 16. Scheme of the structure of the gene in eukaryotes - the image is enlarged

From each gene, an immature, or pre-RNA, is first synthesized, which contains both introns and exons.

After this, the splicing process takes place, as a result of which the intron regions are excised, and a mature mRNA is formed, from which a protein can be synthesized.

Rice. 20. Alternative splicing process - the image is enlarged

Such an organization of genes allows, for example, when different forms of a protein can be synthesized from one gene, due to the fact that exons can be fused in different sequences during splicing.

Rice. 21. Differences in the structure of genes of prokaryotes and eukaryotes - the image is enlarged

MUTATIONS AND MUTAGENESIS

mutation called a persistent change in the genotype, that is, a change in the nucleotide sequence.

The process that leads to mutation is called mutagenesis, and the organism all whose cells carry the same mutation mutant.

mutation theory was first formulated by Hugh de Vries in 1903. Its modern version includes the following provisions:

1. Mutations occur suddenly, abruptly.

2. Mutations are passed down from generation to generation.

3. Mutations can be beneficial, deleterious or neutral, dominant or recessive.

4. The probability of detecting mutations depends on the number of individuals studied.

5. Similar mutations can occur repeatedly.

6. Mutations are not directed.

Mutations can occur under the influence of various factors. Distinguish between mutations caused by mutagenic impacts: physical (eg ultraviolet or radiation), chemical (eg colchicine or reactive oxygen species) and biological (eg viruses). Mutations can also be caused replication errors.

Depending on the conditions for the appearance of mutations are divided into spontaneous- that is, mutations that have arisen under normal conditions, and induced- that is, mutations that arose under special conditions.

Mutations can occur not only in nuclear DNA, but also, for example, in the DNA of mitochondria or plastids. Accordingly, we can distinguish nuclear And cytoplasmic mutations.

As a result of the occurrence of mutations, new alleles can often appear. If the mutant allele overrides the normal allele, the mutation is called dominant. If the normal allele suppresses the mutated one, the mutation is called recessive. Most mutations that give rise to new alleles are recessive.

Mutations are distinguished by effect adaptive, leading to an increase in the adaptability of the organism to the environment, neutral that do not affect survival harmful that reduce the adaptability of organisms to environmental conditions and lethal leading to the death of the organism in the early stages of development.

According to the consequences, mutations are distinguished, leading to loss of protein function, mutations leading to emergence the protein has a new function, as well as mutations that change the dose of a gene, and, accordingly, the dose of protein synthesized from it.

A mutation can occur in any cell of the body. If a mutation occurs in a germ cell, it is called germinal(germinal, or generative). Such mutations do not appear in the organism in which they appeared, but lead to the appearance of mutants in the offspring and are inherited, so they are important for genetics and evolution. If the mutation occurs in any other cell, it is called somatic. Such a mutation can manifest itself to some extent in the organism in which it arose, for example, lead to the formation of cancerous tumors. However, such a mutation is not inherited and does not affect offspring.

Mutations can affect parts of the genome of different sizes. Allocate genetic, chromosomal And genomic mutations.

Gene mutations

Mutations that occur on a scale smaller than one gene are called genetic, or dotted (dotted). Such mutations lead to a change in one or more nucleotides in the sequence. Gene mutations includesubstitutions, leading to the replacement of one nucleotide by another,deletions leading to the loss of one of the nucleotides,insertions, leading to the addition of an extra nucleotide to the sequence.

Rice. 23. Gene (point) mutations

According to the mechanism of action on the protein, gene mutations are divided into:synonymous, which (as a result of the degeneracy of the genetic code) do not lead to a change in the amino acid composition of the protein product,missense mutations, which lead to the replacement of one amino acid by another and can affect the structure of the synthesized protein, although often they are insignificant,nonsense mutations, leading to the replacement of the coding codon with a stop codon,mutations leading to splicing disorder:

Rice. 24. Mutation schemes

Also, according to the mechanism of action on the protein, mutations are isolated, leading to frame shift readings such as insertions and deletions. Such mutations, like nonsense mutations, although they occur at one point in the gene, often affect the entire structure of the protein, which can lead to a complete change in its structure. when a segment of a chromosome rotates 180 degrees Rice. 28. Translocation

Rice. 29. Chromosome before and after duplication

Genomic mutations

Finally, genomic mutations affect the entire genome, that is, the number of chromosomes changes. Polyploidy is distinguished - an increase in the ploidy of the cell, and aneuploidy, that is, a change in the number of chromosomes, for example, trisomy (the presence of an additional homologue in one of the chromosomes) and monosomy (the absence of a homolog in the chromosome).

Video related to DNA

DNA REPLICATION, RNA CODING, PROTEIN SYNTHESIS

(If the video is not displayed, it is available on

In this lesson, we will learn about the importance of protein biosynthesis for living organisms, about the two stages of protein biosynthesis in a cell, transcription and translation, and show how the nucleotide sequence in DNA encodes the amino acid sequence in a polypeptide. We will also characterize the genetic code and its main properties from the standpoint of the unity of origin of all living organisms on the Earth, and consider the features of transcription in eukaryotes.

Transcription- the mechanism by which the sequence of bases in one of the chains of the DNA molecule is "rewritten" into the complementary sequence of mRNA bases.

Transcription requires the presence of the enzyme RNA polymerase. Since there can be many genes in one DNA molecule, it is very important that RNA polymerase starts the synthesis of messenger RNA from a strictly defined place in DNA, otherwise information about a protein that does not exist in nature (not needed by the cell) will be recorded in the mRNA structure. Therefore, at the beginning of each gene there is a special specific sequence of nucleotides called promoter(see Fig. 7). RNA polymerase “recognizes” the promoter, interacts with it, and thus starts the synthesis of the mRNA chain from the right place. The enzyme continues to synthesize mRNA, adding new nucleotides to it, until it reaches the next “punctuation mark” in the DNA molecule - terminator. This is a nucleotide sequence indicating that mRNA synthesis must be stopped.

Rice. 7. Synthesis of mRNA

In prokaryotes, synthesized mRNA molecules can immediately interact with ribosomes and participate in protein synthesis. In eukaryotes, mRNA first interacts with nuclear proteins and enters the cytoplasm through nuclear pores, where it interacts with ribosomes, and protein biosynthesis occurs.

Bacterial ribosomes are different from eukaryotic ribosomes. They are smaller and contain a simpler set of proteins. This is widely used in clinical practice, since there are antibiotics that selectively interact with prokaryotic ribosome proteins, but have no effect on eukaryotic proteins. In this case, the bacteria either die, or their growth and development stops.

There are antibiotics that selectively affect one of the stages of protein synthesis, such as transcription. These include rifamycins, which are produced by actinomycetes of the genus Streptomyces. Rifampicin is the best antibiotic in this class.

Bibliography

1. Kamensky A.A., Kriksunov E.A., Pasechnik V.V. General biology 10-11 class Bustard, 2005.
2. Biology. Grade 10. General biology. Basic level / P.V. Izhevsky, O.A. Kornilova, T.E. Loshchilin and others - 2nd ed., revised. - Ventana-Graf, 2010. - 224 pages.
3. Belyaev D.K. Biology 10-11 class. General biology. A basic level of. - 11th ed., stereotype. - M.: Education, 2012. - 304 p.
4. Agafonova I.B., Zakharova E.T., Sivoglazov V.I. Biology 10-11 class. General biology. A basic level of. - 6th ed., add. - Bustard, 2010. - 384 p.

1. Bio-faq.ru ().
2. Biouroki.ru ().
3. Youtube.com().
4. sbio.info().

Homework

1. Questions 1, 2 at the end of paragraph 26 (p. 101) Kamensky A.A., Kriksunov E.A., Pasechnik V.V. "General biology", grade 10-11 ()
2. What is the role of the enzyme RNA polymerase in the process of mRNA synthesis?
3. What is a promoter and what is its role in mRNA synthesis?
4. What is a terminator and what is its role in mRNA synthesis?
5. What is the further fate of the synthesized mRNA in the cell of prokaryotes and eukaryotes?

They line up in chains and, thus, sequences of genetic letters are obtained.

Genetic code

The proteins of almost all living organisms are built from only 20 types of amino acids. These amino acids are called canonical. Each protein is a chain or several chains of amino acids connected in a strictly defined sequence. This sequence determines the structure of the protein, and therefore all its biological properties.

C

CUU (Leu/L)Leucine
CUC (Leu/L) Leucine
CUA (Leu/L)Leucine
CUG (Leu/L) Leucine

In some proteins, non-standard amino acids such as selenocysteine ​​and pyrrolysine are inserted by the stop codon-reading ribosome, which depends on the sequences in the mRNA. Selenocysteine ​​is now considered as the 21st, and pyrrolysine as the 22nd amino acid that makes up proteins.

Despite these exceptions, the genetic code of all living organisms has common features: a codon consists of three nucleotides, where the first two are defining, codons are translated by tRNA and ribosomes into a sequence of amino acids.

Deviations from the standard genetic code.

Example	codon	Usual meaning	Reads like:
Some types of yeast of the genus Candida	CUG	Leucine	Serene
Mitochondria, in particular Saccharomyces cerevisiae	CU(U, C, A, G)	Leucine	Serene
Mitochondria of higher plants	CGG	Arginine	tryptophan
Mitochondria (in all studied organisms without exception)	UGA	Stop	tryptophan
Mammalian mitochondria, Drosophila, S.cerevisiae and many simple	AUA	Isoleucine	Methionine = Start
prokaryotes	GUG	Valine	Start
Eukaryotes (rare)	CUG	Leucine	Start
Eukaryotes (rare)	GUG	Valine	Start
Prokaryotes (rare)	UUG	Leucine	Start
Eukaryotes (rare)	ACG	Threonine	Start
Mammalian mitochondria	AGC, AGU	Serene	Stop
Drosophila mitochondria	AGA	Arginine	Stop
Mammalian mitochondria	AG(A, G)	Arginine	Stop

The history of ideas about the genetic code

Nevertheless, in the early 1960s, new data revealed the failure of the "comma-free code" hypothesis. Then experiments showed that codons, considered by Crick to be meaningless, can provoke protein synthesis in a test tube, and by 1965 the meaning of all 64 triplets was established. It turned out that some codons are simply redundant, that is, a number of amino acids are encoded by two, four or even six triplets.

see also

Notes

1. Genetic code supports targeted insertion of two amino acids by one codon. Turanov AA, Lobanov AV, Fomenko DE, Morrison HG, Sogin ML, Klobutcher LA, Hatfield DL, Gladyshev VN. Science. 2009 Jan 9;323(5911):259-61.
2. The AUG codon encodes methionine, but also serves as a start codon - as a rule, translation begins from the first AUG codon of mRNA.
3. NCBI: "The Genetic Codes", Compiled by Andrzej (Anjay) Elzanowski and Jim Ostell
4. Jukes TH, Osawa S, The genetic code in mitochondria and chloroplasts., Experientia. 1990 Dec 1;46(11-12):1117-26.
5. Osawa S, Jukes TH, Watanabe K, Muto A (March 1992). "Recent evidence for evolution of the genetic code". microbiol. Rev. 56 (1): 229–64. PMID 1579111.
6. SANGER F. (1952). "The arrangement of amino acids in proteins.". Adv Protein Chem. 7 : 1-67. PMID 14933251 .
7. M. Ichas biological code. - Peace, 1971.
8. WATSON JD, CRICK FH. (April 1953). «Molecular structure of nucleic acids; a structure for deoxyribose nucleic acid.". Nature 171 : 737-738. PMID 13054692 .
9. WATSON JD, CRICK FH. (May 1953). "Genetical implications of the structure of deoxyribonucleic acid.". Nature 171 : 964-967. PMID 13063483 .
10. Crick F.H. (April 1966). "The genetic code - yesterday, today, and tomorrow." Cold Spring Harb Symp Quant Biol.: 1-9. PMID 5237190.
11. G. GAMOW (February 1954). "Possible Relationship between Deoxyribonucleic Acid and Protein Structures.". Nature 173 : 318. DOI: 10.1038/173318a0 . PMID 13882203 .
12. GAMOW G, RICH A, YCAS M. (1956). "The problem of information transfer from the nucleic acids to proteins.". Adv Biol Med Phys. 4 : 23-68. PMID 13354508 .
13. Gamow G, Ycas M. (1955). STATISTICAL CORRELATION OF PROTEIN AND RIBONUCLEIC ACID COMPOSITION. ". Proc Natl Acad Sci U S A. 41 : 1011-1019. PMID 16589789 .
14. Crick FH, Griffith JS, Orgel LE. (1957). CODES WITHOUT COMMAS. ". Proc Natl Acad Sci U S A. 43 : 416-421. PMID 16590032.
15. Hayes B. (1998). "The Invention of the Genetic Code." (PDF reprint). American scientist 86 : 8-14.

Literature

• Azimov A. Genetic code. From the theory of evolution to the decoding of DNA. - M.: Tsentrpoligraf, 2006. - 208 s - ISBN 5-9524-2230-6.
• Ratner V. A. Genetic code as a system - Soros Educational Journal, 2000, 6, No. 3, pp. 17-22.
• Crick FH, Barnett L, Brenner S, Watts-Tobin RJ. General nature of the genetic code for proteins - Nature, 1961 (192), pp. 1227-32

Links

• Genetic code- article from the Great Soviet Encyclopedia

Wikimedia Foundation. 2010 .

DNA and RNA nucleotides Purines: adenine, guanine Pyrimidines: cytosine, thymine (uracil)	codon- a triplet of nucleotides encoding a specific amino acid.
tab. 1. Amino acids commonly found in proteins
Name	Abbreviation
1. Alanine	Ala
2. Arginine	Arg
3. Asparagine	Asn
4. Aspartic acid	asp
5. Cysteine	Cys
6. Glutamic acid	Glu
7. Glutamine	Gln
8. Glycine	gly
9. Histidine	His
10. Isoleucine	ile
11. Leucine	Leu
12. Lysine	Lys
13. Methionine	Met
14. Phenylalanine	Phe
15. Proline	Pro
16. Series	Ser
17. Threonine	Thr
18. Tryptophan	trp
19. Tyrosine	Tyr
20. Valine	Val

The genetic code, which is also called the amino acid code, is a system for recording information about the sequence of amino acids in a protein using the sequence of nucleotide residues in DNA that contain one of the 4 nitrogenous bases: adenine (A), guanine (G), cytosine (C) and thymine (T). However, since the double-stranded DNA helix is ​​not directly involved in the synthesis of the protein that is encoded by one of these strands (i.e. RNA), the code is written in the language of RNA, in which uracil (U) is included instead of thymine. For the same reason, it is customary to say that a code is a sequence of nucleotides, not base pairs.

The genetic code is represented by certain code words - codons.

The first code word was deciphered by Nirenberg and Mattei in 1961. They obtained an extract from E. coli containing ribosomes and other factors necessary for protein synthesis. The result was a cell-free system for protein synthesis, which could assemble a protein from amino acids if the necessary mRNA was added to the medium. By adding synthetic RNA, consisting only of uracils, to the medium, they found that a protein consisting only of phenylalanine (polyphenylalanine) was formed. So it was found that the triplet of UUU nucleotides (codon) corresponds to phenylalanine. Over the next 5-6 years, all codons of the genetic code were determined.

The genetic code is a kind of dictionary that translates a text written with four nucleotides into a protein text written with 20 amino acids. The rest of the amino acids found in the protein are modifications of one of the 20 amino acids.

Properties of the genetic code

The genetic code has the following properties.

1. Tripletity Each amino acid corresponds to a triple of nucleotides. It is easy to calculate that there are 4 3 = 64 codons. Of these, 61 are semantic and 3 are meaningless (terminating, stop codons).
2. Continuity(there are no separating characters between nucleotides) - the absence of intragenic punctuation marks;

   Within a gene, each nucleotide is part of a significant codon. In 1961 Seymour Benzer and Francis Crick experimentally proved the triplet code and its continuity (compactness) [show]

   

   The essence of the experiment: "+" mutation - the insertion of one nucleotide. "-" mutation - loss of one nucleotide.

   A single mutation ("+" or "-") at the beginning of a gene or a double mutation ("+" or "-") spoils the entire gene.

   A triple mutation ("+" or "-") at the beginning of a gene spoils only part of the gene.

   A quadruple "+" or "-" mutation again spoils the entire gene.

   The experiment was carried out on two adjacent phage genes and showed that

   1. the code is triplet and there are no punctuation marks inside the gene
   2. there are punctuation marks between genes
3. Presence of intergenic punctuation marks- the presence among the triplets of initiating codons (they begin protein biosynthesis), codons - terminators (indicate the end of protein biosynthesis);

   Conventionally, the AUG codon also belongs to punctuation marks - the first after the leader sequence. It performs the function of a capital letter. In this position, it codes for formylmethionine (in prokaryotes).

   At the end of each gene encoding a polypeptide, there is at least one of 3 termination codons, or stop signals: UAA, UAG, UGA. They terminate the broadcast.

4. Collinearity- correspondence of the linear sequence of mRNA codons and amino acids in the protein.
5. Specificity- each amino acid corresponds only to certain codons that cannot be used for another amino acid.
6. Unidirectional- codons are read in one direction - from the first nucleotide to the next
7. Degeneracy, or redundancy, - several triplets can encode one amino acid (amino acids - 20, possible triplets - 64, 61 of them are semantic, i.e., on average, each amino acid corresponds to about 3 codons); the exception is methionine (Met) and tryptophan (Trp).

   The reason for the degeneracy of the code is that the main semantic load is carried by the first two nucleotides in the triplet, and the third is not so important. From here code degeneracy rule : if two codons have two identical first nucleotides, and their third nucleotides belong to the same class (purine or pyrimidine), then they code for the same amino acid.

   However, there are two exceptions to this ideal rule. These are the AUA codon, which should correspond not to isoleucine, but to methionine, and the UGA codon, which is the terminator, while it should correspond to tryptophan. The degeneracy of the code obviously has an adaptive value.

8. Versatility- all the properties of the genetic code listed above are characteristic of all living organisms.

   codon	Universal code	Mitochondrial codes
   		Vertebrates	Invertebrates	Yeast	Plants
   UGA	STOP	trp	trp	trp	STOP
   AUA	ile	Met	Met	Met	ile
   CUA	Leu	Leu	Leu	Thr	Leu
   AGA	Arg	STOP	Ser	Arg	Arg
   AGG	Arg	STOP	Ser	Arg	Arg

   Recently, the principle of the universality of the code has been shaken in connection with the discovery by Berell in 1979 of the ideal code of human mitochondria, in which the code degeneracy rule is fulfilled. In the mitochondrial code, the UGA codon corresponds to tryptophan and AUA to methionine, as required by the code degeneracy rule.

   Perhaps, at the beginning of evolution, all the simplest organisms had the same code as the mitochondria, and then it underwent slight deviations.

9. non-overlapping- each of the triplets of the genetic text is independent of each other, one nucleotide is part of only one triplet; On fig. shows the difference between overlapping and non-overlapping code.

   In 1976 φX174 phage DNA was sequenced. It has a single stranded circular DNA of 5375 nucleotides. The phage was known to encode 9 proteins. For 6 of them, genes located one after another were identified.

   It turned out that there is an overlap. The E gene is completely within the D gene. Its start codon appears as a result of a one nucleotide shift in the reading. The J gene starts where the D gene ends. The start codon of the J gene overlaps with the stop codon of the D gene by a two-nucleotide shift. The design is called "reading frame shift" by a number of nucleotides that is not a multiple of three. To date, overlap has only been shown for a few phages.

10. Noise immunity- the ratio of the number of conservative substitutions to the number of radical substitutions.

    Mutations of nucleotide substitutions that do not lead to a change in the class of the encoded amino acid are called conservative. Mutations of nucleotide substitutions that lead to a change in the class of the encoded amino acid are called radical.

    Since the same amino acid can be encoded by different triplets, some substitutions in triplets do not lead to a change in the encoded amino acid (for example, UUU -> UUC leaves phenylalanine). Some substitutions change an amino acid to another from the same class (non-polar, polar, basic, acidic), other substitutions also change the class of the amino acid.

    In each triplet, 9 single substitutions can be made, i.e. you can choose which of the positions to change - in three ways (1st or 2nd or 3rd), and the selected letter (nucleotide) can be changed to 4-1 = 3 other letters (nucleotides). The total number of possible nucleotide substitutions is 61 by 9 = 549.

    By direct counting on the table of the genetic code, one can verify that of these: 23 nucleotide substitutions lead to the appearance of codons - translation terminators. 134 substitutions do not change the encoded amino acid. 230 substitutions do not change the class of the encoded amino acid. 162 substitutions lead to a change in the amino acid class, i.e. are radical. Of the 183 substitutions of the 3rd nucleotide, 7 lead to the appearance of translation terminators, and 176 are conservative. Of the 183 substitutions of the 1st nucleotide, 9 lead to the appearance of terminators, 114 are conservative and 60 are radical. Of the 183 substitutions of the 2nd nucleotide, 7 lead to the appearance of terminators, 74 are conservative, and 102 are radical.

Ecology of life. Psychology: At all times, people were interested in their future, so they often turned to fortune-tellers and soothsayers. Influential people in power were especially worried about what fate had in store for them, so they could keep personal prophets with them. In more ancient times, for example, among the Greeks, even the gods themselves depended on fate and obeyed the goddesses of fate.

At all times, people were interested in their future, so they often turned to fortune-tellers and soothsayers. Influential people in power were especially worried about what fate had in store for them, so they could keep personal prophets with them. In more ancient times, for example, among the Greeks, even the gods themselves depended on fate and obeyed the goddesses of fate. In modern times, science and scientists are already involved in fate, there are many interesting discoveries that help us understand our essence and future.

Science has found out that indeed, there is a certain scenario of fate based on the human genetic code, on which depends what temperament he will have, and what abilities he will have.

The genetic code is formed by our parents and contains the qualities and capabilities. But their presence does not always mean their implementation - they can develop under favorable conditions or not develop at all.

Abilities are realized to the maximum extent in psychologically healthy people who are constantly trying to develop spiritually and physically. They are always learning and reaching new stages of development. People suffering from various neurotic disorders find many excuses and reasons why they fail to achieve success, they blame fate and life for this.

If temperament is a physiological characteristic and depends on the gene set, then the character is formed in the process of education, with the help and direct participation of parents. While the child is still dependent, mom and dad and how they behave play a big role in his life. Education plays a very important role, it is like a sculptor - he creates a finished work from the base.

Two children raised in the same family will differ in character and behavior, because they have a different genetic code and temperament, so as a result, brothers and sisters may not be alike at all. Character is a system of persistent, almost constant individual personality traits that reflect her attitude and behavior towards herself, people and work. The character has several basic qualities - integrity, activity, hardness, stability and plasticity.

Quantitative parameters

Integrity- this is the absence of contradictions in relation to people, oneself, the world around and work. Integrity is expressed in balance, in the totality of all the traits and interests of the individual, in the compatibility of attitudes to different aspects of life. I believe that most characters are integral, in the sense that a person's external behavior reflects his internal system of relations.

This means that if a person behaves duplicitously, then inside he also has sharp contradictions in his content. So women often unsuccessfully choose their partners, being psychologically unprepared and not knowing what compliments and declarations of love mean to their chosen ones.

You need to listen carefully and weigh every word. If a man tells a girl that there is no one more beautiful than her, that she is kinder and better than anyone, then you have a womanizer in front of you. He has someone to compare with, and so he can soon be carried away by another, and each next one will also be the most beautiful.

If a young man assures that he does not see the meaning of life without his beloved, that without her he will be lost and completely disappear, then most likely he is an alcoholic or someone who will definitely become one in the future. It is extremely important to know these behavioral points, the wider your horizons, the less likely you are to have unhappy personal stories in your life.

Activity expressed in the ability to counteract adverse circumstances and the amount of energy that goes into the fight against obstacles. Depending on the activity, the characters are strong and weak. The strength of character directly depends on the sociogen - the personality complex. A person with a weak character can also fulfill the requirements dictated by the sociogen, because the implementation of activity is determined by character. And if the direction of activity is combined with fate, then a person will have enough energy.

Hardness manifests itself in the perseverance and perseverance of a person in the process of achieving a goal and defending his opinion. At times, being too strong of character can become stubbornness. Stability determines the invariability of our character, despite the variability of the world, events and our position in society. Character is a fairly stable characteristic, so it is extremely difficult to change it. Individuals with an unstable character are likely to have many psychological problems in general, and one of the main ones is instability.

Plastic- the ability to adapt to the changing world, the ability to change and adapt to a completely unusual reality, in stressful situations. If even with fundamental changes the character is unchanged, this indicates its rigidity.

Quantitative parameters

The famous psychotherapist Bern, taking into account the huge variety of character qualities, identified three main parameters by which character can be determined: relationships with oneself are “I”, relationships with loved ones are “You”, relationships with all people in general are “They” .

Berne suggested that these qualities, instilled in a person by parents in childhood, can have both positive and negative connotations, and determine in the future his behavior and life path, which he called the "script". Often people do not understand why such events happen to them, and do not connect them with their childhood. I added a fourth parameter to the Bern system - "Labor".

If a person's childhood went well and he received a good upbringing, then all parameters will be positive, with a plus sign. But if parents made mistakes in upbringing, then, accordingly, some or all parameters acquire a minus sign, and a complex can form - a sociogen, which will greatly influence the behavior and fate of a person.

The individual is harmonious and healthy personality with the parameter "I" with "+". This means that he has the right upbringing, he adequately evaluates himself and realizes he is successful. Do not confuse attitude with self-esteem. The position is practically not realized by a person and is formed under the influence of parents in childhood, its direction is quite difficult to change.

Self-esteem may depend on the situation. If a person has too high requirements for himself and for events, then self-esteem is low. No success and good luck will satisfy a person, he will always want even better, always see shortcomings and minuses.

At positions "You" with "+" relationships with close and surrounding people are prosperous, friendly, and bring joy. A person is always ready to help his loved ones, support him, he considers them successful people. If “-” prevails in the “You” parameter, this means that the person’s mood is initially hostile and conflicting with respect to close people. Often such personalities are distinguished by sharp humor, criticism of everything and everyone, captiousness and discontent. To build relationships with such people, you have to constantly give in to them.

When communicating, they often choose the role of the Persecutor, but there are also Redeemers. In this role, aggression is not visible at first glance. For example, these are leaders who take on all the important issues and complex tasks, thereby hindering the growth of their colleagues.

When parameter "They" is set to "+"- a person likes to communicate with people, meet and make new friends. In people, he sees a lot of positive, interesting and worthy. If the parameter “They” is with “-”, then the person first notices flaws in people, and only then their virtues. At the same time, he himself is extremely shy, difficult to communicate and reluctant to make contact and make new acquaintances.

When "Labor" for an individual in "+", then he enjoys the process of work, prefers to solve complex problems for self-development and professional growth, he enjoys finding creative solutions to issues. The material component is not so important for him, but he achieves high performance and success.

If "Labor" has a "-" sign, then the person has a clear focus on material gain. Money, not development, is his primary concern in any job. Therefore, he is constantly chasing large sums and a better life, forgetting to live here and now in the pursuit.

If “-” is present in one of the parameters, then the positive value of the others is doubly enhanced, for example, if “You” is with “-”, then the positive value of “I” may be too exaggerated.

Now it is clear to us that a person can be harmonious, healthy and prosperous only with all positive values. Only such a person will correctly and adequately perceive himself, his victories and defeats, his loved ones and their shortcomings and pluses. He will successfully communicate with people, expand his circle of acquaintances, succeed in work and his favorite business, experience life's upheavals with wisdom and calmness.

This will be of interest to you:

There are such people and there are many of them. And in order to increase the number of such personalities, young parents should raise their children more carefully, without interfering with their development and learning about the world. Support, but do not interfere, do not dictate your own rules and do not break the psyche of children.

After all, no one bothers the tree to grow and it grows strong and healthy, and so do children - you just need to help a little, but do not try to impose your life plan. The child himself knows what he wants and what he is interested in, and it is best not to interfere in his choice, because this is his destiny. published