What is included in DNA. code of life
From the school biology course, everyone knows that DNA is a “data bank” that stores information about all living things. It is DNA that makes it possible to transmit data on the development and functioning of living organisms during their reproduction. Deoxyribonucleic acid is the basis of all living things. It is thanks to this molecule that all organisms are able to maintain their population. What do you know about human DNA?
In 1869, the world learned about the existence of DNA: this discovery was made by Johann Friedrich Miescher. And almost 100 years later (1953), two prominent scientists made a sensational discovery: DNA consists of a double helix. These scientists were Francis Crick and James Watson. Since then, for more than 50 years, scientists around the world have been trying to uncover all the secrets of DNA.
Human DNA - a mystery solved:
- The DNA of all people on the planet is 99.9% identical, and only 0.1% unique. It is this 0.1% that determines who and what we are. Sometimes it happens that this value (0.1%) manifests itself in a very unexpected way: children are born that look not like their parents, but like the great-grandmother or great-grandfather of one of the parents, and sometimes even more distant ancestors appear.
– We are 30% salad and 50% banana! And this is true: the DNA of each of us, regardless of age, gender, skin color and other characteristics, is identical with the DNA of lettuce leaves and bananas by 30 and 50 percent, respectively.
– Erythrocytes (red blood cells) are the only cells that lack DNA.
– There are 80,000 genes in human DNA, and 200 of them are inherited from bacteria.
- Very rarely, people are born who have not 1, but 2 sets of DNA. Such people are called chimeras, in their bodies the organs have different DNA.
Humans only have 2 fewer chromosomes than chimpanzees.
The human genetic code has 2 meanings. It was previously thought that the value is 1, but the American scientist John Stamatoyannopoulos, together with his team, discovered the second value in 2013. Thanks to this discovery, Western medicine began to develop in the direction of studying the human genome, which in the future will allow "genetic" treatment.
- There is a "Disk of Immortality" in space, which contains the digitized DNA of some outstanding personalities.
“There are living organisms on our planet whose DNA, under the most favorable living conditions, could provide them with immortality. But man is not one of them.
And these are far from all the mysteries of a small molecule, without which life on Earth would be impossible.
A new look at DNA
DNA for most of us is a deep mystery. We hear this word, we seem to understand its meaning, but we don’t even imagine how complicated this thing is and why it is actually needed. So let's try to figure this out together. First, let's talk about what we were taught in school, and then about what we were not taught.
DNA (deoxyribonucleic acid) is the main human program. From a chemical point of view, this is a very long polymer molecule, which has the form of two chains, spirally twisting around each other. Each strand is made up of repeating "building blocks" called nucleotides. Each nucleotide is made up of sugar (deoxyribose), phosphate group and actually nitrogen base. The bonds between nucleotides in a chain are formed by deoxyribose and a phosphate group. And nitrogenous bases provide a link between the two helical chains. That is actually the creation of living matter. Foundations are of four types. And it is their sequence that forms the genetic code.
The Human genetic code contains about three billion base pairs of DNA and about 23,000 genes (according to the latest estimates), which are responsible for all the signs and qualities inherent in us. This includes everything that we receive from nature, as well as what we inherit from parents and their parents. A gene is the unit of heredity of a living organism. It may contain information about eye color, how to create a kidney, and hereditary diseases such as Alzheimer's. So heredity is not only the qualities of parents, but also the general qualities of a person. We can say that the genes contain everything that is human in us, along with the unique features inherited from our parents. You may also have heard of RNA (ribonucleic acid). It is involved in the transcription process, which actually begins the production and management of proteins. DNA is the template on which RNA is created and the blueprint followed by the process.
Listen carefully: this tiny double helix molecule can only be seen with a very powerful electron microscope. But it consists of three billion parts! Can you imagine how small these parts are? In fact, we see only the form of DNA discovered by Watson and Crick in England in 1953 on the basis of X-ray data obtained by Rosalind Franklin.<…>
It took another 43 years before, in February 2001, scientists were able to draw the structure of the entire DNA molecule.<…>
Then the real work began, because the study of the structure showed only the general chemical structure of DNA. Imagine that these are letters in a giant book. Now scientists knew every letter, but had no idea what language it was! They needed to decipher the language in order to see the whole picture, understand the words in the book, and find the genes. It was then that they discovered that things were taking an unexpected turn. The best scientists and the most powerful computers in the country struggled to find the codes that they expected to see in the chemical structure of the human genome.
We think in three dimensions. There's nothing you can do about it. This is our reality, and we cannot hope that we will escape it. But often it prevents us from seeing the big picture. Science is now beginning to loudly declare that the Universe and everything in it are multidimensional. So sooner or later we will have to invent mathematics that can fit such a model, as well as discover new physical laws and learn to think more broadly. In the meantime, scientists are making very serious assumptions that the human genome is linear and that the entire human genetic structure is contained in three billion "letters" of DNA. But it's not.<…>
Against all logic, scientists could not find the codes, although they absolutely knew that they were there. They used the best modern computers capable of cracking codes in search of the symmetry that any language generates. And they found her. The find certainly blew them away, and at the same time gave them the greatest biological mystery of the century.
Of the entire chemical structure of the most complex Human genome, only 4% carry a code! Only protein-coding DNA contains a clear code for the production of genes, and its presence there was quite obvious. It's so three-dimensional that you could literally see the "start" and "stop" marks in the gene sequence! Like today's computer codes, chemistry adjusted to our expectations, but only a small part of the Human genome was involved in the production of the 23,000 genes of the human body. Everything else was there, as it were, "for nothing."
Let me give you an analogy for such disappointment. A flying saucer appears above us. She does amazing tricks - hovering in the air, defying gravity and behaving as we would expect from a flying saucer. Then she lands. We approach and realize that there is no one inside. Apparently, this is just a robot probe sent to Earth. Suddenly, the top of the plate rises, inviting the best scientists to take a look at how it works. We are very excited, realizing that we are close to unraveling some mysteries. We are about to discover a new physics! We start looking for the engine, and a surprise awaits us: the engine compartment is filled to the brim with some kind of garbage! No, perhaps, it is more like foam granules, which we fill up as a filler in packages with dishes. These granules are clearly connected to each other, some of them even move, but they do nothing. No structure is visible in this material; it just fills the space. You dig up the "filler" with a shovel, throw out the pellets bucket after bucket, and finally find a tiny shiny object with some kind of wires coming out of it. Obviously, this object is the engine, the heart of the ship. So Littel! Fits in the palm of your hand and controls everything! You are trying to run it. And then it turns out that without the "filler" the flying saucer does not want to fly. You put the pellets back in and the plate flies again! So, it turns out that the "filler" still does something? Or not? How can a filler do something? The error is understandable. We expected to see an engine - something shiny, wired, linear and complete in its structure - and we found it. What seemed to us "filler", "packaging", we immediately threw away. Do you understand what the oversight is and what the metaphor is?
There was an anecdote. DNA is made up of three billion parts, most of which do nothing! Only four tiny percent do all the work! What nonsense! We know that nature is very rational. We can observe the evolution of living beings even during one of our lives, and we understand how expedient nature is. If the fish are trapped in an underground cave, then after ten years or so, their eyes disappear. Nature strikes out everything that is not necessary, and we see it everywhere. However, 96% of our DNA is just junk! We, the pinnacle of evolution, are 96% garbage? This is contrary to everything that we observe in nature, but that's exactly what happened.. The parts of DNA that do not code for protein have been declared "garbage" by even the best minds. The non-protein-coding regions were random, had neither symmetry nor visible purpose, and appeared to be useless.
Meet the Non-3D Thinkers
Let's try to approach our flying saucer with new ideas. Perhaps this seemingly chaotic "filler" is not part of the engine at all. Maybe it's a map! After all, the ship must know where it's going. Then you think it's some other type of card. Maybe in a quantum state, a ship needs a quantum map? What could it be? That there must be something that would allow it to exist in a linear world, but could give instructions to a tiny shiny engine to control the vessel in three dimensions. In this case, we know that the ship has multidimensional characteristics because it can control its mass. We also know from our quantum physics that when we move into a multidimensional world, time and space as we know them cease to exist. These two concepts are replaced by potentials and a completely non-linear and confusing profusion of "event rules" that make very little sense to us in the third dimension. Thus, the strange and chaotic "filler" is not disordered at all - it just looks so to three-dimensional creatures (you, me and scientists)! It must be exactly where it is in order for the engine to be able to move the ship. One could say that "filler" is an engine modifier and it should be present in significant amounts because it has so much to "tell" the engine about how to move in a multi-dimensional way.
For years we have put up with the term "junk DNA". However, suddenly we began to think differently. "What if,- someone said, - there is no code in the garbage, because it should not be there? What if this 96% of DNA somehow contains non-linear quantum rules that govern the encoded parts? This is a completely new and controversial concept - but at least it goes beyond the limited 3D logic!
Here is a report from UC San Diego on July 13, 2007, broadcast on CBS news:
The so-called "junk DNA" - 96% of the human genome, seemingly useless - may play a more important role than its name suggests, US scientists say. An international team of scientists has found that some of the "junk" DNA can serve as a framework to help properly organize the other 4%. “Some of the junk DNA can be considered punctuation marks, commas and periods, helping to understand the meaning of the encoded regions of the genome,” says co-author of this theory Victoria Lunyak, a researcher at KUD.
I think we're starting to see a multi-dimensional aspect of our biology that is obviously huge! What if 96% of our DNA is a set of instructions for the other 4%? Then this part is not chaotic at all, it just seems so to 3D thinking. Can punctuation marks appear to be letters of the alphabet? No. Then what is it? Are they symmetrical? Are they pronounced somehow? No. If you look at the punctuation marks in our language, it may seem that they are arranged in a random order. If you, for example, looked at this page without knowing anything about the language and its structure, then the punctuation marks would seem meaningless to you. They do not have symmetry. If you run this page through a supercomputer, it will eventually identify the words and their likely meanings, but not the punctuation marks.
Think about it. The engine we were looking for in a flying saucer was indeed there. This 4% portion encoding the protein serves as the "brilliant motor". And "garbage" is 96%, similar to granular filler. Now we suspect that something completely different is going on, and 96% may actually be a multi-dimensional constructor template, and 4% just an engine that obeys its design.
Doesn't this ratio seem interesting to you? According to the teachings of Kryon, only 8% of DNA is in the third dimension, and 92% of DNA controls the rest.
Perhaps we are witnessing a gradual recognition of the fact that the functions of DNA differ significantly from our expectations and that it is something more complex than just a code that can be read chemically.
excerpts from Kryon and Lee Carroll's "The Twelve Layers of DNA"
Molecular biology is one of the most important branches of biological sciences and involves a detailed study of the cells of living organisms and their components. The scope of her research includes many vital processes, such as birth, respiration, growth, death.
The invaluable discovery of molecular biology was the deciphering of the genetic code of higher beings and the determination of the cell's ability to store and transmit genetic information. The main role in these processes belongs to nucleic acids, which are distinguished in nature by two types - DNA and RNA. What are these macromolecules? What are they made of and what biological functions do they perform?
What is DNA?
DNA stands for deoxyribonucleic acid. It is one of the three macromolecules of the cell (the other two are proteins and ribonucleic acid), which ensures the preservation and transmission of the genetic code for the development and activity of organisms. Simply put, DNA is the carrier of genetic information. It contains the genotype of an individual, which has the ability to reproduce itself and transmits information by inheritance.
As a chemical substance, acid was isolated from cells as early as the 1860s, but until the middle of the 20th century, no one assumed that it was capable of storing and transmitting information. 
For a long time it was believed that these functions are performed by proteins, but in 1953 a group of biologists managed to significantly expand the understanding of the essence of the molecule and prove the primary role of DNA in the preservation and transmission of the genotype. The discovery was the discovery of the century, and scientists received the Nobel Prize for their work.
What is DNA made of?
DNA is the largest of biological molecules and consists of four nucleotides, consisting of a phosphoric acid residue. Structurally, the acid is quite complex. Its nucleotides are interconnected by long chains, which are combined in pairs into secondary structures - double helixes.
DNA tends to be damaged by radiation or various oxidizing substances, due to which a mutation process occurs in the molecule. The functioning of an acid directly depends on its interaction with another molecule - proteins. Interacting with them in the cell, it forms the substance chromatin, within which information is realized.
What is RNA?
RNA is a ribonucleic acid containing nitrogenous bases and phosphoric acid residues. 
There is a hypothesis that it is the first molecule that acquired the ability to self-reproduce back in the era of the formation of our planet - in prebiological systems. RNA is still included in the genomes of individual viruses, performing in them the role that DNA plays in higher beings.
Ribonucleic acid consists of 4 nucleotides, but instead of a double helix, as in DNA, its chains are connected by a single curve. Nucleotides contain ribose, which is actively involved in metabolism. Depending on the ability to encode a protein, RNA is divided into matrix and non-coding.
The first acts as a kind of intermediary in the transfer of encoded information to ribosomes. The latter cannot code for proteins, but have other capabilities - translation and ligation of molecules.
How is DNA different from RNA?
In their chemical composition, acids are very similar to each other. Both are linear polymers and are an N-glycoside created from five-carbon sugar residues. The difference between them is that the sugar residue of RNA is ribose, a monosaccharide from the pentose group, which is easily soluble in water. The sugar residue of DNA is deoxyribose, or a derivative of ribose, which has a slightly different structure. 
Unlike ribose, which forms a ring of 4 carbon atoms and 1 oxygen atom, in deoxyribose the second carbon atom is replaced by hydrogen. Another difference between DNA and RNA is their size - larger. In addition, among the four nucleotides that make up DNA, one is a nitrogenous base called thymine, while in RNA, instead of thymine, its variant, uracil, is present.
DNA - deoxyribonucleic acid, in the form of a double helix, located in the nucleus of the cell. DNA contains genetic information, with the help of which a huge number of cellular processes take place, the transfer of genetic information during cell division and construction.
If you "untwist" the DNA molecule, then its length will be about 3 meters. DNA stores such a large amount of information that if you take one molecule as a symbol (a letter of the alphabet, a space, or a punctuation mark), you get a book of 27 trillion pages.
In 1990, the US Department of Energy, together with the US National Institutes of Health, invested 3 billion dollars in a program to decipher the human genome. The program was designed for 15 years. Already 13 years later, decoding work was done and information about the complete human genome was obtained. Interestingly, scientists have deciphered the complete sequence of DNA molecules, but have not been able to obtain information about what each of them “encodes”. To date, it is believed that about 20-25 thousand genes are encoded in a human DNA cell, i.e. consecutive DNA molecules responsible for certain functions.
Although humanity is only on the verge of understanding the entire DNA code, today we can understand in more detail the research of human theory and determine our genotype, find out the predisposition to certain diseases and the causes of genetic diseases.
Deciphering DNA, in the foreseeable future, can change medicine and open the door to "personalized medicine" using new therapeutic methods and procedures, up to the replacement of certain genes in the body. Certain DNA research methods are aimed at obtaining information about the predispositions for various skills. At the state level, deciphering the human genome can be very useful. It would be very convenient to have such a "baggage" of knowledge about the country's population. For example, by processing the data obtained, predict the predisposition to diseases of each individual and implement targeted programs for disease prevention. As it turned out, deciphering your DNA can become a very common procedure, along with obtaining a TIN number.
Of course, there are still many gaps in the understanding of the genome, but decoding one's own DNA is already useful knowledge today. With the discovery of new genes, in the future it will be possible to "upgrade" knowledge on the existing code.
Nutrinews has compiled a selection of companies where you can get a DNA test:
23andme (USA)
99$ + 60$ (sending of biological material is not carried out from the territory of Russia)
The company was the first in the world to offer to decipher DNA for a record low price of $99. This step changed the approach to genetic research and allowed a huge number of people to find out information about their origin and body characteristics. The decryption process takes two weeks.
23andme had problems with the US Food and Drug Administration (FDA) in 2013, after the order, the company cannot provide complete DNA information to its US customers, due to the lack of government approval of the procedure. The company has the right to provide its customers from the USA with only limited information on the interpretation of the genome, and the resulting report must be for informational purposes only.
On the territory of Russia, 23andme does not work due to the ban on sending parcels containing biological materials. But you can get around it by sending your test tube from the 23andme kit from the territory of the EU countries, for example, from Finland.
Genotek (Russia)
From 14,990 to 425,000 rubles.
Today Genotek is one of the most popular companies in Russia for DNA decoding. Founded in 2010 by MSU graduates, the company was able to raise a $500,000 investment from RuStars Ventures that should have paid off by now, given that some analysts estimate the company's turnover is around $1 million a year.
Do not be afraid, for 425,000 rubles. the company offers full genome sequencing (sequencing) on Life Technologies and Illumina licensed equipment. The service offers various payment options, including with the help of a financial partner POSFinance, which offers an annual installment plan. If you are ready to limit yourself to only the necessary data obtained from certain sections of DNA, then you can choose cheaper "packages". So the package "My genome +", for 90,000 rubles, provides the main indicators for:
- predisposition to various diseases;
- Physiological characteristics of the body;
- Tolerance to various foods, etc.
The most affordable test is "Genealogy" for 14,990 rubles. It includes: searching for relatives, data on the origin of the paternal and maternal lines, the Talents and Sports test (it will tell you what talents and abilities the customer has and which, most likely, the unborn child will inherit). All testing information is stored electronically on the company's website and is available at any time through your personal account. The time for obtaining test results is quite long - from 1.5 to 3 months.
My gene (Russia)
From 21,000 to 30,000 rubles.
The company was one of the first in Russia to provide a service for decoding the human genome. Founded in 2007. "My Gen" has branches in Moscow, St. Petersburg, Yekaterinburg, Perm and Rostov-on-Don, which speeds up the process of decoding and obtaining data, but in general, the procedure may take 2 months.
According to the company, it provides reliable genetic information.
All tests of the company "My gene" can be conditionally divided into five groups. By ordering the study "Diet" you will receive individual recommendations on nutrition and an explanation of the features of your eating behavior. Testing in the "Sports" package will tell you in which sports you can achieve great results or how to make your workouts more effective. You can find out the individual characteristics of the tolerance of various types of drugs by doing the "Pharmacy" analysis. The study for genetic diseases is divided into two tests: "Monogenic diseases" and "Polygenic diseases". The first study is useful when planning a pregnancy. Based on its results, you will learn about diseases that “sleep” in your genes, but in some cases can lead to a child’s illness if the partner has the same tendency. The second study reveals individual genetic predispositions to dangerous diseases and will allow you to adjust your lifestyle.
Each individual test costs 21,000 rubles, if you choose two, the cost will be 25,000 rubles, and for a complete “genetic passport” (five studies), you will have to pay 30,000 rubles.
Atlas (Russia)
From 14900 rub.
The Atlas company works in two directions: the first is the development of a medical clinic in Moscow, the second is a DNA decoding service. A genetic test costs 14,900 rubles. It includes health scores (ranging from disease risk to drug response), sports and nutrition scores (from optimal diet to optimal sport), and personality and background information. In addition to the test, the cost of the service includes an online consultation with a geneticist. Based on the results of the analysis, the user will receive recommendations on all items with explanations.
According to the company itself, their offer is now the most profitable in Russia both in terms of the number of analyzed indicators and in terms of cost. At the same time, Atlas has impressive financial resources, only 10 million rubles were spent on the development of an internal system for storing and processing DNA information.
LiftGen (USA)
From 30,000 to 70,000 rubles.
Lifegen is an American company that opened its representative office in Russia several years ago. It provides an opportunity to make standard tests, according to the results of which you will receive information about health, beauty and sports with expert recommendations. Lifegen also does genetic testing for couples about to have children. The results that clients will receive contain a forecast about the health of the unborn child and advice on how to prevent possible problems. Another research package is called "My Talented Child". Parents will receive a booklet with information on their child's health, talents, and sports predispositions.
The minimum package of services costs 30,000 rubles. For 50-70 thousand rubles, the client will be analyzed for more DNA sections and he will receive a brochure (at least 70 pages) about his own health.
“One of our differences from other companies is the submission form. The client receives a book about his own health, - says Arseniy Duchinov, Managing Partner of Lifegen. - There is no place for depression. The positive illustrations smooth out the negative information. Plus, the information is presented clearly and understandably. We translate from medical into Russian.”
Dukhinov admits that prices are lower in the American division of the company. But there is another market. US genetic testing companies are not authorized to provide health information.
MyGenetics (Russia)
From 4,900 to 29,800 rubles.
The Novosibirsk company MyGenetics is developing with the help of a partner network. It is joined by companies wishing to sell DNA tests and other services in the regions of Russia and in the CIS countries. To date, MyGenetics has some of the lowest prices for minimal genotype research. For example, a study of seven genes, as a result of which the client finds out his optimal type of diet and metabolic rate, costs 4,900 rubles. The same test, but with information about the body's reaction to various products and environmental factors - 9,900 rubles. The most complete study (28 genes) costs 14,900 rubles. The results contain extended information about digestion and suitable sports. If you want to get results in the form of a glossy magazine (it looks more like a book), you will have to pay twice as much. Although, in this case, consultations of a geneticist and a nutritionist are also included in the price.
But those who are interested in knowing about their origin should pay attention to other companies, MyGenetics does not provide such information.
At the end of 2013, Google launched the Google Genomics service, designed to store the decoded genome and automate queries to it. And in 2014, Google partnered with the Broad Institute of MIT and Harvard to create the Genome Analysis Toolkit. And now this system is part of Google Genomics, available to users as a service. The decoded genome weighs approximately 100 GB. Genome storage will cost you $25/year. Google Genomics contains many tools, as well as a database derived from over a million sequenced genomes. Of course, such a service is more useful for scientists, but it is also available to those who want to independently analyze their DNA. But most importantly, Google Genomics provides the ability to use the genome as a database that can be analyzed using various applications. Right now, Google is trying to attract scientists and developers to create such applications.
Recently, the company's social network has made a lot of noise. Previously, data about users got there automatically, now - only with the prior permission of the test-takers. A case led to a revision of the policy when a married couple broke up, it turned out on the social network that the husband had an illegitimate child.
Another important consequence of the disclosure of DNA results is the reaction of employers. It is unlikely that, other things being equal, they will prefer a candidate with a tendency, for example, to schizophrenia. Since 2008, a law has been in force in the United States prohibiting the use of genetic information in hiring. There is no such restriction in Russia.
Most likely, the medicine of the future will be engaged in the analysis of very large arrays of information about the patient. And a significant part of this information will be obtained from the results of human gene analysis. Knowing about the genetic predispositions and weaknesses of the body, the doctor will be able to accurately determine the diagnosis and prescribe an effective individual treatment for the patient. Interestingly, the world's first digitized human genome was formed over 15 years, and it cost $ 3 billion. At the Consumer Electronics Show in Las Vegas, the American biotech company Life Technologies presented a new version of its Ion Proton DNA human genome sequencing machine. This device, the size of an office printer, can decipher the human genome in one day at a cost of just $1,000. Until now, the record low cost of such an operation was $ 4-5 thousand, and it took at least 3 days to decrypt. And if we go back a couple of years ago, then progress in general will be exciting. In 2009, the minimum cost of genome sequencing was $1 million (and 6-8 weeks), in 2010 it dropped to $50,000 (4-6 weeks).
It is very interesting what awaits us in the future.
In this and several subsequent posts, I will tell you a little about what DNA consists of, how information about our body is encoded in it.
I think many readers associate DNA with the object shown in the picture:
And this is the right association, it is indeed DNA. Let's look at the main features of the DNA molecule. Firstly, it looks like a spiral, they usually say a double helix (I hope the picture makes it clear why), and secondly, it consists of several identical sections arranged in some sequence. Let's look a little deeper into the structure of DNA. First, straighten it into one line:
As you can see, the top and bottom parts are very similar, so let's look at only one half of the DNA:
The considered half of the DNA consists of four identical building blocks, located one after the other in some sequence. These building blocks are called nucleotides (deoxynucleotides). Nucleotides differ from each other in nitrogenous bases, which in DNA are represented by adenine, thymine, guanine and cytosine. Nitrogenous bases are usually denoted by the following Latin letters adenine - A, thymine - T, guanine - G and cytosine - C. In one of the previous posts, I called the mentioned thymine, adenine, guanine and cytosine nucleotides. This is not entirely accurate, but often, when it comes to DNA, nucleotides and nitrogenous bases are not particularly distinguished. Perhaps you do not know what a nitrogenous base is, or, even more so, a nucleotide. It's okay, all these concepts are from chemistry, these are chemicals that have oxygen, hydrogen, nitrogen and phosphorus in their composition. For geneticists, the sequence of nucleotides in the structure of DNA is important. It is the sequence of nucleotides that affects your predispositions and speaks about your origin. Now in this and future posts, the letters A, T, G and C will denote nucleotides in DNA.
The 4 letters A, T, G and C are the alphabet of your genetic code.
Let's return now to the untwisted DNA, consisting of two parts.
As you can see, in DNA, nitrogenous bases combine with each other, while adenine always combines with thymine, and guanine with cytosine. This means that adenine is complementary to thymine, and cytosine is complementary to guanine. The reasons for such intelligibility of nitrogenous bases with whom they combine lie in chemistry. We will not go into details of how it all works, we will only remember that in the DNA double helix T will always be opposite A, A C against G.
Due to this property of nitrogenous bases to selectively combine with other bases, we can always determine from one part of DNA, the second part, putting opposite A - T, and opposite C - G and vice versa, therefore, when talking about the nucleotide sequence in DNA, only one is used a series of letters, e.g. TCCAGCAT...
The totality of all human DNA is called the genome.
Finally, why does DNA have such a name? Here, many well-educated readers will obviously say that DNA is an abbreviation for deoxyribonucleic acid. But why is the molecule we have considered called deoxyribonucleic acid? The answer is in chemistry. Chemists love to give meaningful names to the substances they study. Even if the name is very long, breaking it into elements, you can understand what substance it describes, and in the case of DNA.
Let's look at the structure of a single nucleotide:
First, why is deoxyribo...? Each nucleotide contains deoxyribose, the chemical circled in red. Secondly, why nucleic? Each nucleotide contains a nitrogenous base, which gives the "nucleic" component. Third, why acid? What is circled in blue in the picture is a residue of phosphoric acid.
Enough for now, I will describe the rest of the interesting nuances of DNA in our body in the following posts.
