Biomedical Computation

Molecular Genetics, DNA and Protein Sequence: General Information

Molecular biology is a complex of biological sciences that study the mechanisms of storage, transmission and implementation of genetic information, the structure and functions of irregular biopolymers (proteins and nucleic acids). Molecular biology is aimed at deepening knowledge of the molecular foundations of the vital activity of living organisms, which are widely used in modern biotechnology and biomedicine.

What is DNA?

What is DNA in simple words and how does it work? Physically, it is a macromolecule that not only stores hereditary information but is also detailed instructions for the development of the whole organism conditionally from one universal cell.

If we compare a person with a computer and all the diversity of biological life with various forms of robotic computers, DNA in this comparison will be a biological programming language. The only difference is that biological species are much more complex and perfect than the most advanced computers.

For example, all species have the unique ability to divide and transform cells.

In fact, in the course of cell self-reproduction, biomass not only materializes from itself but also physically transforms to solve a variety of highly specialized problems.

And all the variety of living species, their forms, unique abilities come from the division of one universal cell. This alone goes far beyond all modern genetic achievements.

Discovery history

In fact, the discovery of deoxyribonucleic acid happened twice. The first discovery of the molecule was made by Johann Friedrich Miescher in 1869. As a Swiss biologist and physiologist, he was able to isolate a large molecule with a high content of nitrogen and phosphorus from the cells contained in pus.

He called his discovery nuclein, and later – nucleic acid, when its acidic properties were discovered. Scientists originally believed that the main function of a nucleic acid is to store phosphorus.

And the assumption that it could contain hereditary information caused ridicule since the structure of the molecule seemed to them too simple and monotonous for such functions. It was also believed that the presence of deoxyribonucleic acid is characteristic only of animal cells, and plants contain only RNA.

But in 1934-1935 Soviet biologists A. N. Belozersky and A. R. Kizel clearly refuted this and published the results of their work in Soviet and world scientific journals.

The rediscovery of DNA already as a carrier of hereditary information and not only was accomplished in 1944.

A team of researchers consisting of Oswald Avery, Colin Macleod and McLean McCarthy conducted experiments with the transformation of bacteria and proved that deoxyribonucleic acid plays a major role in this process.

The importance of DNA in medicine

The discovery of DNA in medicine, the decoding of this acid are events whose significance can hardly be exaggerated. Much of today’s breakthrough technology and research is directly or indirectly based on this fundamental discovery for science.

If we did not know about genes, there would not be many modern methods of treatment and diagnostics, many technical inventions. In fact, there would be no genetics as a full-fledged independent science. The study of the cell and how it functions would be stalled.

And without this knowledge, many discoveries in this area would have been impossible.

Today, knowledge about genes helps many people to:

  • Learn about the disease much earlier than the onset of the first symptoms. Early treatment is always more successful;
  • Find out your genetics is easy – all you need to do is make a DNA analysis. With the help of it, you can understand what diseases you have a predisposition to, or, for example, how you should eat, which vitamins you just need to include in your diet and which substances, on the contrary, need to be limited, etc.;
  • Find your loved ones, learn a lot of details about your kind;
  • Overcome hereditary diseases that previously seemed incurable;
  • Solve the problem of many millennia and find the elixir of immortality or a pill for all diseases.

DNA structure

Everyone has heard that deoxyribonucleic acid has a double-stranded structure. If you need the answer in more details, let’s understand better what this structure consists of:

  1. Nucleotides are basic structural elements;
  2. Two chains of genes, twisted into a spiral;
  3. Each strand consists of nucleotides that code for a specific gene;
  4. The two chains are linked together by hydrogen bonds.

The chains of nucleotides also contain completely unexplored structures that, at first glance, do not participate in any way in physiological processes. These rather large areas are called garbage.

DNA composition

If we talk about the composition of DNA in more detail, then nucleotides are the basic structural element, the building blocks of which both strands of the helix are composed. Nucleotides are classified into 4 types: adenine, thymine, guanine, and cytosine. And only four of these nucleotides record all hereditary information and make up all known genes.

Both gene chains are twisted into a spiral for a reason. Of all four different nucleotides, they can be opposite each other in different chains only in two pairs: adenine-thymine and guanine-cytosine. In science, these pairs are called complementary.

A strong hydrogen bond arises between paired nucleotides. At the same time, the connection between adenine and thymine is slightly weaker than between guanine and cytosine. But the chains are twisted into a spiral for other reasons:

  • Studies have shown that twisting helps to shorten the length of the gene chain by 5-6 times. And during supercoiling (this also happens), the chain length can be reduced by as much as 30 times!
  • In addition to the fact that a pair of gene chains are twisted into a spiral, there is also supercoiling. Histone proteins in the form of thread spools are responsible for this phenomenon. The already twisted double helix winds around these proteins like a thread. This leaves no doubt that helicity as such specifically serves to more compactly pack hereditary information into the cell.

Role in the cell

Of course, one double helix is ​​not able to contain the entire amount of information required for such a complex project as the human body. Perhaps that is why these chains are paired, which makes them look like the letter “X”. Chromosomes, in turn, are also paired, and a person has 46 pairs of them.

In addition to the fact that the chromosome contains detailed instructions on the functioning of the cell, it also provokes the cell to produce certain proteins with a variety of properties by activating the genes relevant to the moment. For example, the gene of old age is actively involved in the fight against tumors, which ages its poor-quality cells and prevents them from dividing indefinitely.

What are nucleotides?

Nucleotides are the four elements that are the backbone of the bio-language of DNA strand programming, just as zero and one are the backbone of assembler (the first of the programming languages). The unique sequence of nucleotides in one of the two strands of DNA is the gene. If you just slightly change this sequence, then the gene will already be damaged or destroyed.

Protein synthesis

Protein synthesis is the key mystery of human physiology. Proteins start and control all processes in the body at the cellular level. If we fully study which genes and groups of genes in which cases trigger the synthesis of proteins and these proteins themselves, then science will learn to completely tune and reconfigure the entire human body.

Today we know that genes or regions with genes are activated in the double helix of deoxyribonucleic acid in response to various stimuli.

Information from these sites is copied to RNA (ribonucleic acid), and RNA transfers information from the cell nucleus into the cell itself. The RNC acts as a kind of herald who reads the decree to all employees.

So RNA makes the cell behave in one way or another and produce various proteins.

If DNA is the cabinet of ministers who govern everything and make all decisions, then RNA is the press attaché. It notifies everyone about new orders and decrees and distributes instructions in the field.

RNA is a ribonucleic acid that can copy the shapes of different regions of deoxyribonucleic acid and transport them from the cell nucleus to its intracellular space.

DNA decoding

DNA decoding became possible only thanks to the discovery of the polymerase chain reaction, and it happens as follows:

The sample containing the deoxyribonucleic acid samples heats up quickly. This is necessary for the double helix to unwind and split into two independent strands.

  • Polymerase adheres to the region of the gene chain of interest to researchers. This procedure takes place at slightly lower temperatures;
  • Polymerase activates division of the caught area – this is how the synthesis of genes necessary for studying areas occurs;
  • Areas are impregnated with a special paint that glows when exposed to a directed laser beam. This is how a picture of the gene is obtained, which can be studied and deciphered.

Thus, the study of DNA has become an affordable tool that allows people to learn a lot about themselves and can help maintain health, get rid of existing diseases, lose weight, maintain youth and improve the quality of their life!