Interesting and important topics in biophysics. Physiology and biophysics of the human body. The ratio of the phases of the action potential and excitability

One of the most ancient sciences is, of course, biology. People's interest in the processes occurring within themselves and the surrounding beings arose several thousand years before our era.

Observation of animals, plants, natural processes was an important part of people's lives. Over time, a lot of knowledge has accumulated, methods of studying wildlife and the mechanisms that occur in it have been improved and developed. This led to the emergence of many sections that make up a complex science in total.

Biological research in various areas of life makes it possible to obtain new valuable data that are important for understanding the structure of the planet's biomass. Use this knowledge for practical human purposes (space exploration, medicine, agriculture, chemical industry, and so on).

Many discoveries made it possible to make biological research in the field of the internal structure and functioning of all living systems. The molecular composition of organisms, their microstructure has been studied, many genes have been isolated and studied from the genome of humans and animals, plants. The merits of biotechnology, cellular and allow you to get several harvests of plants per season, as well as to breed animal breeds that give more meat, milk and eggs.

The study of microorganisms made it possible to obtain antibiotics and create tens and hundreds of vaccines that allow defeating many diseases, even those that used to take thousands of lives in epidemics of people and animals.

Therefore, the modern science of biology is the limitless possibilities of mankind in many branches of science, industry and health preservation.

Classification of biological sciences

One of the very first appeared private sections of the science of biology. Such as botany, zoology, anatomy and taxonomy. Later, disciplines more dependent on technical equipment began to form - microbiology, virology, physiology, and so on.

There are a number of young and progressive sciences that emerged only in the 20th-21st century and play an important role in the modern development of biology.

There is not one, but several classifications by which biological sciences can be ranked. Their list is quite impressive in all cases, consider one of them.

Biology	Private sciences	Botany	deals with the study of the external and internal structure, physiological processes, phylogenesis and distribution in nature of all plants existing on the planet (flora)	Includes the following sections: algology; dendrology; taxonomy; anatomy; morphology; physiology; bryology; paleobotany; ecology; geobotany; ethnobotany; plant reproduction.
		Zoology	deals with the study of the external and internal structure, physiological processes, phylogenesis and distribution in nature of all animals existing on the planet (fauna)	Disciplines included in: Disciplines: topographic anatomy; comparative; systematic; age; plastic; functional; experimental.
		Anthropology	a number of disciplines that study the development and formation of a person in a biological and social environment in a complex	Sections: philosophical, judicial, religious, physical, social, cultural, visual.
		Microbiology	studies the smallest living organisms, from bacteria to viruses	Disciplines: virology, bacteriology, medical microbiology, mycology, industrial, technical, agricultural, space microbiology
		General Sciences	Systematics	the tasks include developing the basis for the classification of all life on our planet with the aim of strict ordering and identification of any representative of the biomass
	Morphology		description of external signs, internal structure and topography of the organs of all living beings	Sections: plants, animals, microorganisms, fungi
	Physiology		studies the features of the functioning of a particular system, organ or part of the body, the mechanisms of all processes that ensure its vital activity	Plants, animals, human, microorganisms
	Ecology		the science of the relationship of living beings with each other, the environment and man	Geoecology, general, social, industrial
	Genetics		studies the genome of living beings, the mechanisms of heredity and variability of traits under the influence of various conditions, as well as historical changes in the genotype during evolutionary transformations
	biogeography		considers the resettlement and distribution of certain species of living beings on the planet
	evolutionary doctrine		reveals the mechanisms of the historical development of man and other living systems on the planet. Their origin and development
	Complex sciences that arose at the junction with each other	Biochemistry	studies the processes occurring in the cells of living beings from a chemical point of view
		Biotechnology	considers the use of organisms, their products and or parts for human needs
		Molecular biology	studies the mechanisms of transmission, storage and use of hereditary information by living beings, as well as the functions and fine structure of proteins, DNA and RNA.	Related sciences: genetic and cell engineering, molecular genetics, bioinformatics, proteomics, genomics
		Biophysics	it is a science that studies all possible physical processes occurring in all living organisms, from viruses to humans	Sections of this discipline will be discussed below.

Thus, we have tried to capture the main diversity that is the biological sciences. This list with the development of technology and methods of study is expanding and replenishing. Therefore, a unified classification of biology does not exist today.

Progressive biosciences and their significance

The youngest, modern and progressive sciences of biology include such as:

• biotechnology;
• molecular biology;
• space biology;
• biophysics;
• biochemistry.

Each of these sciences was formed no earlier than the 20th century, and therefore is rightfully considered young, intensively developing and the most significant for practical human activity.

Let us dwell on such of them as biophysics. This is a science that appeared around 1945 and became an important part of the entire biological system.

What is biophysics?

To answer this question, first of all, it is necessary to point out its close contact with chemistry and biology. In some issues, the boundaries between these sciences are so close that it is difficult to make out which of them is specifically involved and in priority. Therefore, it is worth considering biophysics as a complex science that studies the deep physical and chemical processes occurring in living systems at the level of both molecules, cells, organs, and at the level of the Biosphere as a whole.

Like any other, biophysics is a science that has its own object of study, goals and objectives, as well as worthy and significant results. In addition, this discipline is closely correlated with several new directions.

Objects of study

For biophysics they are biosystems at different organizational levels.

1. viruses, unicellular fungi and algae).
2. The simplest animals.
3. Individual cells and their structural parts (organelles).
4. Plants.
5. Animals (including humans).
6. ecological communities.

That is, biophysics is the study of the living from the point of view of the physical processes occurring in it.

The tasks of science

Initially, the tasks of biophysicists were to prove the presence of physical processes and phenomena in the life of living beings and to study them, finding out their nature and significance.

Modern tasks of this science can be formulated as follows:

1. To study the structure of genes and the mechanisms that accompany their transmission and storage, modifications (mutations).
2. Consider many aspects of cell biology (the interaction of cells with each other, chromosomal and genetic interactions, and other processes).
3. To study polymer molecules (proteins, nucleic acids, polysaccharides) in combination with molecular biology.
4. To reveal the influence of cosmogeophysical factors on the course of all physical and chemical processes in living organisms.
5. More deeply reveal the mechanisms of photobiology (photosynthesis, photoperiodism, and so on).
6. Implement and develop methods of mathematical modeling.
7. Apply the results of nanotechnology to the study of living systems.

From this list, it is obvious that biophysics studies a lot of significant and serious problems of modern society, and the results of this science are of great importance for a person and his life.

History of formation

As a science, biophysics was born relatively recently - in 1945, when he published his work "What is life from the point of view of physics." It was he who first noticed and indicated that many laws of physics (thermodynamic, laws of quantum mechanics) take place precisely in the life and work of organisms of living beings.

Thanks to the work of this man, the science of biophysics began its intensive development. However, even earlier, in 1922, an institute of biophysics was created in Russia, headed by P.P. Lazarev. There, the main role is assigned to the study of the nature of excitation in tissues and organs. The result was the identification of the importance of ions in this process.

1. Galvani discovers electricity and its significance for living tissues (bioelectricity).
2. A. L. Chizhevsky is the father of several disciplines studying the influence of space on the Biosphere, as well as ionization radiation and electrohemodynamics.
3. The detailed structure of protein molecules was studied only after the discovery of X-ray diffraction analysis (X-ray diffraction analysis). This was done by Perutz and Kendrew (1962).
4. In the same year, the three-dimensional structure of DNA was discovered (Maurice Wilkins).
5. Neher and Zakman in 1991 managed to develop a method for local fixation of the electric potential.

Also, a number of other discoveries allowed the science of biophysics to embark on the path of intensive and progressive modernization in development and formation.

Sections of biophysics

There are a number of disciplines that make up this science. Let's consider the most basic of them.

1. Biophysics of complex systems - considers all the complex mechanisms of self-regulation of multicellular organisms (systemogenesis, morphogenesis, synergogenesis). Also, this discipline studies the features of the physical component of the processes of ontogenesis and evolutionary development, the levels of organization of organisms.
2. Bioacoustics and biophysics of sensory systems - studies the sensory systems of living organisms (vision, hearing, reception, speech, and others), ways of transmitting various signals. Reveals the mechanisms of energy conversion when organisms perceive external influences (irritations).
3. Theoretical biophysics - includes a number of subsciences involved in the study of the thermodynamics of biological processes, the construction of mathematical models of the structural parts of organisms. Also considers kinetic processes.
4. Molecular biophysics - considers the deep mechanisms of the structural organization and functioning of such biopolymers as DNA, RNA, proteins, polysaccharides. He is engaged in the construction of models and graphic images of these molecules, predicts their behavior and formation in living systems. Also, this discipline builds supramolecular and submolecular systems in order to determine the mechanism of construction and action of biopolymers in living systems.
5. Biophysics of the cell. He studies the most important cellular processes: differentiation, division, excitation and biopotentials of the membrane structure. Particular attention is paid to the mechanisms of membrane transport of substances, potential difference, properties and structure of the membrane and its surrounding parts.
6. Biophysics of metabolism. The main ones under consideration are solarization and adaptation of organisms to it, hemodynamics, thermoregulation, metabolism, and the influence of ionization rays.
7. Applied Biophysics. It consists of several disciplines: bioinformatics, biometrics, biomechanics, the study of evolutionary processes and ontogenesis, pathological (medical) biophysics. The objects of study of applied biophysics are the musculoskeletal system, methods of movement, methods of recognizing people by physical features. Medical biophysics deserves special attention. It considers pathological processes in organisms, methods of reconstruction of damaged sections of molecules or structures or their compensation. Gives material for biotechnology. It is of great importance in the prevention of the development of diseases, especially of a genetic nature, their elimination and explanation of the mechanisms of action.
8. Habitat biophysics - studies the physical effects of both the local habitats of beings and the effects of near and far space entities. Also considers biorhythms, the influence of weather conditions and biofields on creatures. Develops measures to prevent negative impacts

All these disciplines make an enormous contribution to the development of understanding the mechanisms of life of living systems, the influence of the biosphere and various conditions on them.

Modern achievements

Some of the most significant events that relate to the achievements of biophysics can be named:

• revealed the mechanisms of cloning organisms;
• the features of transformations and the role of nitric oxide in living systems have been studied;
• the relationship between small and messenger RNAs has been established, which in the future will make it possible to find a solution to many medical problems (elimination of diseases);
• discovered the physical nature of autowaves;
• thanks to the work of molecular biophysicists, aspects of DNA synthesis and replication have been studied, which led to the possibility of creating a number of new drugs for serious and complex diseases;
• computer models of all reactions accompanying the process of photosynthesis have been created;
• methods of ultrasonic research of an organism are developed;
• the connection between cosmogeophysical and biochemical processes has been established;
• predicted climate change on the planet;
• discovery of the significance of the enzyme urokenase in the prevention of thrombosis and the elimination of consequences after strokes;
• also made a number of discoveries on the structure of the protein, the circulatory system and other parts of the body.

Institute of Biophysics in Russia

In our country, they exist. M. V. Lomonosov. The Faculty of Biophysics operates on the basis of this educational institution. It is he who trains qualified specialists for work in this area.

It is very important to give a good start to future professionals. They have a tough job ahead of them. A biophysicist is obliged to understand all the intricacies of the processes occurring in living beings. In addition, students must understand physics. After all, this is a complex science - biophysics. Lectures are structured in such a way as to cover all the disciplines related to and constituting biophysics, and cover consideration of both biological and physical issues.

With the expansion and deepening of human knowledge about living organisms, such branches of science have appeared that study processes and phenomena that simultaneously belong to different fields of knowledge. Among these scientific disciplines biological Physics, or biophysics. What does she study and what are her research methods?

It is known that physics studies the basic laws of nature: the structure of atoms and nuclei, the properties of elementary particles, the interaction of electromagnetic waves and particles, etc. Biophysics, which arose at the intersection of biology and physics, is the science of the basic physical and physico-chemical processes in living body and their regulation.

Biophysicists need to learn the laws of the structure and work of living organisms without violating their properties, keeping the organism in a living, active state. After all, when dying, the body loses its inherent properties, all processes in it change, and it becomes an ordinary inanimate system. Therein lies the great difficulty. Hence the need arose to study living organisms at different "levels" - to study the properties of biological molecules, the characteristic features and operation of cells, to study the joint work of organs in the whole organism, etc. Therefore, such large sections have emerged in biophysics: molecular biophysics, cell biophysics, biophysics management and regulation processes, etc. Let's briefly talk about each of the main sections of biophysics.

Molecular biophysics studies the properties of biological molecules, physicochemical processes in receptor cells. These cells are called receptor or sensitive, as they are the first to perceive signals about light, taste, smell (in Latin "receptio" - I feel).

Molecular biophysics investigates, for example, the processes that take place in the sense organs of animals - in the organs of sight, hearing, touch and smell. We are used to the fact that everything happens in our body simply, naturally, and sometimes we don’t think about how complex biophysical processes are taking place, for example, when we taste sugar or smell flowers. And this is one of the problems that molecular biophysics has been working on for many years. The fact is that sensations of taste or smell are possible due to complex physicochemical processes in receptor cells when molecules of various substances interact with them.

It is known that chemists have created 1 million organic compounds and almost each of them has its own characteristic smell. A person can distinguish several thousand odors, and we feel some substances at extremely low concentrations - only millionths and billionths of a milligram per liter of water. For example, in order to feel substances such as skatole, trinitrobutyltoluene, their concentration of 10 -9 mg / l is sufficient. Animals are much more sensitive than humans. For example, geologists use specially trained dogs to sniff out ore deposits deep underground. Everyone is well aware of the work of sniffer dogs, finding a trace by a negligible smell. But, perhaps, fish and insects excel in the acuteness of smell. Some fish feel an odorous substance, even if it is contained in water in vanishingly small concentrations - only 10 -11 mg / l. Butterflies detect almost one molecule of an odorous substance per 1 m 3 of air.

Molecular biophysics helps to elucidate not only the difference in the sensitivity and structure of the olfactory organs in different animals, but also the process of smell determination itself. It has now been established that there are 6-7 basic odors, different combinations of which explain their diversity. These basic odors correspond to certain types of olfactory cells.

Molecular biophysics studies properties and processes not only in animals, but also in plants. In particular, she is engaged in the study of photosynthesis. Amazing and complex processes take place in the green leaf of birch, bird cherry, apple or wheat. The sun sends a colossal amount of energy to the Earth, which would be wasted if it were not for the green leaves that capture it and create organic matter from water and carbon dioxide with its help and thereby give life to all living organisms.

Photosynthesis takes place in green particles - chloroplasts, located in leaf cells and containing plant pigment - chlorophyll. Portions of light energy (photons) are absorbed by the pigment and produce photo-oxidation of water: it gives its electron to the chlorophyll molecule, and the proton is used to reduce carbon dioxide to carbohydrates. The proton and the electron, as we know, make up the hydrogen atom; this atom "in parts" is taken away from the water molecule. In the process of photosynthesis, oxygen is released, which all living organisms breathe.

The basis of photosynthesis is the very first elementary process: the interaction of portions of light energy (photons) with a chlorophyll molecule. It is this process that is studied by molecular biophysics in photosynthesis in order to know how the conversion of light energy into the energy of chemical bonds and the subsequent transformation of substances takes place. If this fundamental process is fully understood, it can be carried out under artificial conditions. Then humanity will master the fastest and most economical way of obtaining organic substances, hence, food and valuable raw materials, which green plants give to man today.

There is a close connection between the study of cells and the molecular processes occurring in them, that is, between molecular and cellular biophysics. One of them studies molecular changes, the properties of biological molecules and the systems formed by molecules in cells (as they say, submolecular formations), their properties and changes, the other studies the properties and functioning of various cells - excretory, contractile, olfactory, light-sensitive, etc.

development cell biophysics the successes of physics and radio electronics contributed in many ways, it was thanks to these sciences that biophysics received electron microscopes, which made it possible to magnify microscopic objects hundreds of thousands of times. Biophysicists are armed with electron paramagnetic resonance, which can be used to study special active parts of molecules - the so-called free radicals, which play a very important role in all biological processes. With the help of devices highly sensitive to light - photomultiplier tubes (PMT) it became possible to determine extremely small light fluxes. The use of these instruments has led to a great discovery in cell biophysics.

The ability to glow in living organisms has long been known: fireflies and various aquatic organisms, called bioluminescence. But with the help of photomultipliers, it was found that the organs of almost all animals and plants have the ability to glow. This so-called superweak glow - biochemiluminescence - occurs as a result of physicochemical reactions inside cells, and it is associated with intracellular oxidation of lipid substances that make up the structural elements. The free radicals mentioned above play an important role in these processes. By the intensity of the ultra-weak glow, one can monitor the level of oxidative metabolic reactions and the release of energy as a result of various reactions taking place inside the cells.

The discovery of superweak luminescence, the presence of free radicals, and their connection with the vital activity of the cell has dramatically changed the concept of cellular processes. The task of cell biophysics was not only to understand the ultramicroscopic structure of the cell and its organelles, but also to find out how these elements are connected with each other, how they work, what is the reason for the coherence and consistency of the processes occurring in cells.

When studying a cell in an electron microscope, scientists opened up a new world of ultramicroscopic, i.e., the smallest, cellular structures. Intracellular membranes, tubules, tubules, vesicles were found. All these structures, millions of times thinner than a human hair, play a certain role in the life of the cell. Any cell, which seems to be a simple lump of cytoplasm with a nucleus, is a complex formation with a large number of tiny particles (structural elements) that act accurately and consistently, in a strict order, closely interconnected. The number of these structural elements is very large, for example, in a nerve cell there are up to 70 thousand particles - mitochondria, thanks to which the cell breathes and receives energy for its activities.

In any cell of a living organism, the absorption of necessary substances and the release of unnecessary substances take place, respiration and division take place, along with this, the cells perform special functions. Thus, the cells of the retina of the eye determine the strength and quality of light, the cells of the nasal mucosa determine the smell of substances, the cells of various glands secrete physiologically active substances - enzymes and hormones that regulate the growth and development of the body.

About all their great work - seen, heard, identified - the cells of the nervous tissue of animals report by electrical impulses to the brain - the main coordinating center. Biophysics of the cell as a whole and one of its important sections, called cell electrophysiology, they study how cells receive the necessary information from the surrounding space, how this information is encrypted in electrical signals - impulses, how biological currents and potentials are formed in cells.

The cells of a living organism are closely connected with each other, with the brain - the main control center. In the cells themselves, in thousands of their structural elements, ordered biochemical processes take place. What makes these hundreds of thousands of reactions so coordinated and precise?

The fact is that both a cell, and a separate organ, and a whole organism represent a certain system, based on specific laws of regulation and interconnection. These features are studied by the youngest section - biophysics of control and regulation processes.

Let's talk about this branch of biophysics using the following example. Each human organ consists of a large number of cells that perform a specific job. For example, the mucous membrane of the nose, the so-called mucous epithelium, plays a special role in the sense of smell. Its area is not more than 4 cm 2, but it contains almost 500 million olfactory receptor cells. Information about their work is transmitted through nerve fibers, the number of which reaches 50 million, to the olfactory nerve and then to the brain. The signals coming from the cells in the form of primary electrical impulses must be correctly decoded. To do this, they are sent to various parts of the brain, consisting of a huge number of cells. For example, only the cerebral hemispheres contain 2 * 10 10 cells, the cerebellum - 10 11 cells. The brain makes the necessary "decisions" and transmits response signals - instructions on how certain cells, tissues or organs should work. The central nervous system receives hundreds of thousands of various signals from the external environment about sounds, light, smells and signals about the state of the cells of the body itself. From what has been said, it is clear how complex the interconnections are in any living system - in a single cell or the whole organism, how difficult it is to manage cells, regulate their state and control the consistency of all life processes.

This important branch of biophysics relies on patterns discovered by another science - cybernetics. Biophysicists studying the processes of control and regulation, using its methods, have developed a number of electronic models, such as a turtle, a nerve cell, and the process of photosynthesis, which facilitate the study of complex regulatory phenomena in the body.

The study of regulatory processes in a living organism showed that they have an amazing property - self-regulation. Cells, tissues, organs of living organisms are self-regulating, self-organizing, self-adjusting, self-learning systems. This means that the work of cells, organs and the organism as a whole is determined by the properties and qualities inherent in the organism itself. Therefore, every cell or organ on one's own, without outside help regulates the constancy of the composition of the environment inside them. If, under the influence of any factor, their state changes, this amazing property helps them return to their normal state again.

Chloroplasts in leaf cells change their location depending on the intensity of illumination: in strong illumination, they are located along the cell walls (left); with a weak - throughout the cell. This is an example of cellular self-regulation.

Here is just one simple example of such self-regulation. We have already talked about the important role of chloroplasts located in green leaf cells. Chloroplasts are capable of independent movement in cells under the influence of light, since they are very sensitive to it. On a bright sunny day with high light intensity, chloroplasts are located along the cell wall, as if trying to avoid the action of strong light. On overcast, cloudy days, chloroplasts spread over the entire surface of the cell to absorb more rays. The transition of chloroplasts from one position to another under the influence of light (phototaxis) occurs due to cellular self-regulation.

Man's knowledge of nature and various living organisms proceeds so rapidly and leads to such unexpected results and conclusions that they do not fit into the framework of any single science. Biophysics laid the foundation for new branches of science, expanding the horizons of human knowledge. So it stood out as an independent branch of biology radiobiology - the science of the effects of various types of radiation on living organisms, space biology, studying the problems of life in space, mechanochemistry, investigating the conversion of chemical energy into mechanical energy, which occurs in muscle fibers. On the basis of biophysical research, a new science has arisen - bionics, studying living organisms in order to use the principles of their work to create new and more advanced devices and apparatuses.

We talked about only a small part of the research conducted by biophysicists, but much more examples could be given, both in the field of studying molecules, subcellular structures, and the body as a whole. Every day brings new discoveries, inventions, valuable ideas. Our century is a time of great success in all fields of knowledge, including the study of nature.

The history of biological research institutes in Russia goes back to the end of the 19th century and begins with the bites of rabid dogs. Impressed by the success of the rabies vaccine developed by Pasteur, the Institute of Experimental Medicine was established in St. Petersburg at the end of the 19th century. The organization of the institute was initiated and financed by Prince A.P. Oldenburgsky. Before that, the prince had to send one of his officers to Paris for vaccination. In 1917, the Institute of Physics and Biophysics was established in Moscow at the expense of the merchant Kh.S. Ledentsov. This institute was headed by P.P. Lazarev, who soon turned out to be close “to the body of Lenin”: after the assassination attempt on the leader of the world proletariat, he needed an X-ray examination.

Biophysics in Soviet Russia became for some time a "darling of fate." The Bolsheviks were obsessed with innovation in society and showed a willingness to support new directions in science. Later, the Institute of Physics of the Russian Academy of Sciences grew out of this Institute. Note that many fundamental physical discoveries occurred due to the interest of scientists in biological systems. So, the famous Italian Luigi Galvani made discoveries in the field of electricity, studying animal electricity on frogs, and Alessandro Volta guessed that it was a more general physical phenomenon.

In the Soviet Union, the authorities were interested in conducting scientific research on a "broad front". It was impossible to miss any of the promising directions that could promise military or economic advantages in the future. Until the early 1990s, state support ensured the priority development of molecular biology and biophysics. In 1992, the new authorities sent an unambiguous signal to scientists: the salary of a researcher became less than the subsistence level, and scientists were forced to choose between emigration and a change in field of activity. Many biophysicists who did not think about emigrating before had to leave for the West. The community of biophysicists in Russia is relatively small, and if hundreds of researchers out of several thousand leave, it is impossible not to notice this.

At first, Russian biophysics suffered little from "economic" emigration. The development of such means of communication as e-mail and the Internet has made it possible to maintain links between scientists and colleagues. Many began to help their institutes with reagents and scientific literature, and continued research on "their" topics. Well-known scientists, after arriving at a new place, created "platforms" for internships and invited colleagues. The most energetic scientists left, mostly young. This led to the "aging" of scientific personnel, which was also facilitated by the decline in the prestige of the specialty. Due to the inability to live on an academic salary, the influx of students into science has decreased. A generational gap has emerged, which now, after 15 years of change, is beginning to have an ever greater effect: the average age of employees in some laboratories of the Academy of Sciences already exceeds 60 years.

Russian biophysics has not lost its leading positions in a number of areas headed by scientists who were educated in the 60-80s of the twentieth century. Significant discoveries in science were made by these scientists. So, as an example, we can cite the creation in recent years of a new science - bioinformatics, the main achievements of which are related to the computer analysis of genomes. The foundations of this science were laid back in the 60s by a young biophysicist Vladimir Tumanyan, who was the first to develop a computer algorithm for analyzing nucleic acid sequences. From this example, it becomes clear how important it is now to attract gifted young people to science who could lay the foundations for new scientific directions.

Biophysicist Anatoly Vanin discovered the role of nitric oxide in the regulation of cellular processes back in the 1960s. Later it turned out that nitric oxide is of great medical importance. Nitric oxide is the main signaling molecule of the cardiovascular system. The study of the role of nitric oxide in this system was awarded the Nobel Prize in 1998. On the basis of nitric oxide, the world's most popular drug to increase potency "Viagra" was created. Meanwhile, Anatoly Vanin's article "Free radicals of a new type" was published in 1965 in the journal Biophysics. American scientists are now demonstrating it as the first work on nitric oxide in a living organism. A similar story happened with cloning - was the first work also published in the domestic "Biophysics"?

Many achievements in the field of biophysics are associated with the Belousov-Zhabotinsky self-oscillatory reaction discovered by Soviet scientists. This reaction provides an example of self-organization in inanimate nature; it served as the basis for many models of synergetics that are now fashionable. Oleg Mornev from Pushchino recently showed that autowaves propagate according to the laws of optical waves. This discovery sheds light on the physical nature of autowaves, which can also be considered the contribution of biophysicists to physics.

One of the most interesting areas of modern biophysics is the analysis of the binding of small RNAs to messenger RNA encoding proteins. This binding underlies the phenomenon of "RNA interference". The discovery of this phenomenon was awarded the Nobel Prize in 2006. The world scientific community has high hopes that this phenomenon will help fight many diseases. The analysis of the binding mechanisms of RNA molecules has been successfully carried out in recent years by an international group of researchers led by Olga Matveeva, who is currently working in the USA.

The most important area of ​​molecular biophysics is the study of the mechanical properties of a single DNA molecule. The development of fine techniques for biophysical and biochemical analysis makes it possible to monitor such properties of the DNA molecule as stiffness, stretching, bending, and tensile strength. Such properties are revealed in experimental and theoretical work carried out in recent years in Russia under the direction of Sergei Grokhovsky and in the USA under the direction of Carlos Bustamente. These works are closely related to studies of mechanical stresses in a living cell. Donald Ingber was the first to point out the resemblance of the mechanical structures of a living cell to "self-stressed structures". Such structures were invented in the early 1920s by Russian engineer Karl Ioganson and "rediscovered" later by American engineer Buckminster Fuller.

The positions of Russian biophysicists in the field of theory are traditionally strong. The Faculty of Physics of Moscow State University, where the strongest theoreticians in the country worked and taught in the 20th century, gave a lot to graduates of the Department of Biophysics. Graduates of this department put forward a number of original theoretical concepts and created many unique developments that have found their application in medicine. For example, Georgy Gursky and Alexander Zasedatelev developed the theory of binding biologically active compounds to DNA. They suggested that the phenomenon of "matrix adsorption" underlies such binding. Based on this concept, they proposed an original project for the synthesis of low molecular weight compounds. Such compounds can "recognize" certain places on the DNA molecule and regulate the activity of genes. In recent years, this project has been successfully developing, drugs are being synthesized for a number of serious diseases. Alexander Zasedatelev successfully applies his developments to create domestic biochips that allow diagnosing oncological diseases at an early stage. Under the leadership of Vladimir Poroikov, a set of computer programs was created that made it possible to predict the biological activity of chemical compounds according to their formulas. This direction makes it possible to significantly facilitate the search for new medicinal compounds.

Galina Riznichenko and her colleagues developed computer models of the reactions that take place during photosynthesis. She heads the association "Women in Science, Culture and Education", which, together with the Department of Biophysics of the Faculty of Biology, Moscow State University, holds a number of important conferences for the Russian biophysicists community. In Soviet times, there were many such conferences: several times a year, biophysicists gathered for meetings, symposiums, and seminars in Armenia, Georgia, Ukraine, and the Baltic states. With the collapse of the USSR, these meetings ceased, which had a negative impact on the level of research conducted in a number of CIS countries. The Scientific Council for Biophysics at the Academy of Sciences has held two All-Russian Biophysical Congresses over the past 15 years, which stimulated scientific contacts and information exchange between Russian scientists. Conferences dedicated to the memory of Lev Blumenfeld and Emilia Frisman have begun to play an important role in recent years. These conferences are held regularly at the physics departments of Moscow State University and St. Petersburg State University.

Judging by financial indicators, the "palm" for the greatest achievements should be given to the biophysicist Armen Sarvazyan, who created a number of unique developments in the field of studying the human body using ultrasound. These studies are generously funded by the US military department: for example, Sarvazyan owns the discovery of a connection between tissue hydration (the degree of dehydration) and the state of the body. The work of Sarvazyan's laboratory is in demand in connection with the US-led military operations in the Middle East.

Worldview upheavals promise the discovery of Simon Shnol: he discovered the influence of cosmogeophysical factors on the course of physical and biochemical reactions. The point is that the well-known Gauss law, or the normal distribution of measurement errors, turns out to be the result of rough averaging, which is not always valid. In reality, all ongoing processes have certain "spectral" characteristics due to the anisotropy of space. The "cosmic" wind, about which science fiction writers of the 20th century wrote, finds its confirmation in subtle experiments and original concepts of the 21st century.

The most significant for all people living on our planet may be the research of the biophysicist Alexei Karnaukhov. His climate models predict that we will face global cooling followed by warming. Not surprisingly, there has been a huge amount of public interest in this topic. Surprisingly, the film "Day after tomorrow" is based not only on this idea, but even on the specific model of cooling proposed by Karnaukhov. The Gulf Stream, which warms Northern Europe, will cease to bring heat from the Atlantic due to the fact that the Labrador Current, which is opposite to it, will be desalinated due to the melting of glaciers and an increase in the flow of northern rivers, which will make it easier and stop "dive" under the Gulf Stream. The increase in the flow of northern rivers observed in recent years and the melting of glaciers give Karnaukhov's forecasts more and more grounds. The risks of climate catastrophes are increasing sharply, and the public in a number of European countries is already sounding the alarm.

Research by Robert Bibilashvili from the Cardiology Center has led to significant results in curing a number of diseases that were previously considered incurable. It turned out that timely intervention (injection of the urokinase enzyme into areas of the brain of patients affected by a stroke) can completely remove the consequences of even very severe attacks! Urokinase is an enzyme that is formed by blood and vascular cells and is one of the components of the system that prevents the development of thrombosis.

Until recently, Russian biophysics has retained priority in a large number of scientific areas: Vsevolod Tverdislov is engaged in original research in the field of the origin of life, Fazoil Ataullakhanov obtained a number of fundamental results in understanding the functioning of the blood system, under the leadership of Mikhail Kovalchuk a number of areas are developing in a new science - nanobiology, interesting concepts currently being developed by Genrikh Ivanitsky, Vladimir Smolyaninov and Dmitry Chernavsky ...

The world biophysical community enthusiastically greeted the book "Protein Physics", written by Alexei Finkelstein and Oleg Ptitsyn. Together with the book "The Age of DNA" (in the first Russian edition - "The Most Important Molecule") by Maxim Frank-Kamenetsky, this book has become a desktop guide for students and scientists from many countries. In general, over the past 15 years, Russian biophysics, despite a significant reduction in funding, has not lost the ability to generate new ideas and obtain original results. However, the deterioration of the scientific infrastructure and instrument base, the outflow of young people to more profitable sectors of the economy led to the fact that the resources for the further development of science were exhausted. Domestic science has lost a little in the speed and intensity of its development. Science was supported by the dedication of scientists, the help of Western colleagues and foundations, as well as the significance of inertia, determined by the laboriousness of education. The "saving" role here was also played by the conservatism of the predilections of scientists. Science has been supported for centuries thanks to the interest in it of people from the upper strata of society who finance research from their own pockets (think of the Prince of Oldenburg). The well-known aristocracy of academic science saved its bearers from the market temptations of the "transitional period".

Now these "noble dons" in biophysics can no longer find and educate their own kind: young people go to offices not because they do not like science, but because they cannot find a full reward for their labors. Under-education has become the scourge of our time: in order to "make" a real scientist, it takes at least 8-10 years: 5-6 years of study at a university or university and three years in graduate school. All this time, the young man must be supported by his parents, but if he begins to "earn some money", then, as a rule, this ends with leaving "to the office." However, it is rather difficult to find parents who have been ready to nurture their child and satisfy his interest in science for ten years. Such parents could be found in the scientific community if the scientists themselves had sufficient funding. Thanks to a long-term education, a "long-playing" specialist is obtained, however, a break in education halfway leads to "dropouts". It is the irreparable loss of young specialists (and not achievements) in science that is the main result of changes in Russian biophysics. The loss of achievements and the loss of world-class research is a process that still awaits us if young people do not return to science.

Of the recent achievements of foreign scientists, two can be noted: firstly, a group of American researchers from the University of Michigan, led by S.J. Weiss discovered one of the genes responsible for the "three-dimensional" development of biological tissue, and secondly, scientists from Japan showed that mechanical stresses help create artificial vessels. Japanese scientists placed stem cells inside a polyurethane tube and forced fluid through the tube under varying pressure. Pulsation parameters and mechanical stress structures were approximately the same as in real human arteries. The result is encouraging - the stem cells "turned" into the cells lining the blood vessels. This work allows a deeper understanding of the role of mechanical stress in the development of organs. On the agenda is the creation of artificial "spare parts for the repair" of the circulatory system. Science news can be viewed at scientific.ru.

Summing up, we can say that Russian biophysics has lost a lot in the present, but it is threatened by a more serious danger - to lose the future.

Knowledge of human functions is one of the most difficult tasks. The development of science at the first stages occurs - the differentiation of disciplines aimed at a deep study of certain problems. At the first stage, we try to know a certain part, and when we succeed in doing this, another task arises - how to make a general idea. There are scientific disciplines at the junction of the original specialties. This also applies to biophysics, which appeared at the intersection of physiology, physics, physical chemistry and opened up new possibilities in understanding biological processes.

Biophysics- a science that studies physical and physico-chemical processes at different levels of living matter (molecular, cellular, organ, whole organism), as well as patterns and mechanisms of the impact of physical environmental factors on living matter.

Allocate-

• molecular biophysics - kinetics and thermodynamics of processes
• cell biophysics - study of cell structure and physico-chemical manifestations - permeability, formation of biopotentials
• biophysics of the sense organs - physical and chemical mechanisms of reception, energy transformation, information coding in receptors.
• Biophysics of complex systems - processes of regulation and self-regulation and thermodynamic features of these processes
• Biophysics of the impact of external factors - explores the impact on the body of ionizing radiation, ultrasound, vibration, exposure to light

Biophysics tasks

1. Establish patterns of wild nature by studying the physical and chemical phenomena in the body
2. The study of the mechanisms of the influence of physical factors on the body

Euler (1707-1783) - the laws of the theory of hydrodynamics, to explain the movement of blood through the vessels

Lavoisier (1780) - studied the exchange of energy in the body

Galvani (1786) - the founder of the doctrine of biopotentials, animal electricity

Helmholtz(1821)

X-ray - tried to explain the mechanisms of muscle contraction from the position of piezo effects

Arrhenius - laws of classical kinetics to explain biological processes

Lomonosov - the law of conservation and transformation of energy

Sechenov - studied the transport of gas in the blood

Lazarev - the founder of the national biophysical school

Pauling - the discovery of the spatial structure of the protein

Watson and Crick - discovery of the double structure of DNA

Hodgkin, Huxley, Katz - discovery of the ionic nature of bioelectrical phenomena

Prigogine - the theory of thermodynamics of irreversible processes

Eigen - the theory of hypercycles, as the basis of evolution

Sakman, Neher - established the molecular structure of ion channels

Biophysics became in connection with the development of medicine, because. methods of physical influence on the body were used there.

Biology was developing and it was necessary to penetrate the secrets of biological processes occurring at the molecular level

The need of industry, the development of which led to the action of various physical factors on the body - radioactive radiation, vibrations, weightlessness, overloads

Methods of biophysical research

• X-ray diffraction analysis- study of the atomic structure of matter, using X-ray diffraction. The distribution of the electron density of a substance is established from the diffraction pattern, and already from it it is possible to determine which atoms are contained in the substance and how they are located. Study of crystal structures, liquids and protein molecules.
• Column chromatography- different distribution and analysis of mixtures between 2 phases - mobile and stationary. It may be related to varying degrees of substance absorption or to varying degrees of ion exchange. Can be gas or liquid. The distribution of substances is used in capillaries - capillary, or in tubes filled with a sorbent - columnar. Can be done on paper, plates
• Spectral analysis- qualitative and quantitative determination of a substance by optical spectra. The substance is determined either by the emission spectrum - emission spectral analysis or by the absorption spectrum - absorption. The substance content is determined by the relative or absolute thickness of the lines in the spectrum. Also include radiospectroscopy - electron paramagnetic resonance and nuclear magnetic resonance.
• Isotope indication
• electron microscopy
• ultraviolet microscopy- the study of biological objects in UV rays increases the contrast of the image, especially intracellular structures, and it allows you to examine other cells without preliminary staining and fixing the preparation

One of the most important conditions for existence is adequate adaptation of functions, organs and tissues, systems to the environment. There is a constant balancing of the organism and the environment. In these processes, the main process is the regulation and control of physiological functions.

The general laws for the implementation, management and processing of information in different systems are studied by the science of cybernetics (cybernetics is the art of management). The laws of management are common to both humans and technical devices. The emergence of cybernetics was prepared by the development of the theory of automatic control, the development of radio electronics, and the creation of information theory.

This work was presented by Shannon (1948) in "The Mathematical Theory of Communication"

Cybernetics deals with the study of systems of any nature capable of receiving, storing and processing information and using it for management and regulation. Cybernetics studies those signals and factors that lead to certain control processes.

It is of great importance for medicine. The analysis of biological processes makes it possible to qualitatively and quantitatively study the mechanisms of regulation. Information processes of management and regulation are decisive in the body, i.e. are primary, on the basis of which all processes occur.

Systems- an organized complex of elements connected with each other and performing certain functions in accordance with the program of the entire system. The elements of the brain will be neurons. The elements of a team are the people who make it up. Only the crowd is not a cybernetic system.

Program- the sequence of changes in the system in space and time, which can be incorporated into the structure of the system or enter it from the outside.

Connection- the process of interaction of elements with each other, in which there is an exchange of matter, energy, information.

Messages are continuous and discrete.

continuous have the character of a continuously changing value (blood pressure, temperature, muscle tension, musical melodies).

Discrete- consist of separate steps or gradations that differ from each other (portions of mediators, the nitrogenous base of DNA, dots and dashes of Morse code)

The process of coding information is also important. It is encoded by nerve impulses for the perception of information by the nerve centers. Code elements - symbols and positions. Symbols are dimensionless quantities that distinguish something (letters of the alphabet, mathematical signs, nerve impulses, molecules of odorous substances, and positions determine the spatial and temporal arrangement of symbols).

The information code contains the same information as the original message. This is the phenomenon of isomorphism. The code signal has a very low energy value. The arrival of information is evaluated by the presence or absence of a signal.

Message and information are not the same thing, because according to information theory

Information- a measure of the amount of uncertainty that is eliminated after receiving the message.

Possibility of an event a priori information.

The probability of an event after receiving the information is a posteriori information.

The informativeness of the message will be greater if the received information increases the posterior probability.

Information properties.

1. Information makes sense only if there are its receivers (consumer) - "if there is a TV in the room, and there is no one in it"
2. The presence of a signal does not necessarily indicate that information is being transmitted, because there are messages that do not carry anything new for the consumer.
3. Information can be transmitted both on the conscious and subconscious levels.
4. If the event is reliable (i.e. its probability is P=1), the message that it happened does not carry any information for the consumer
5. Message about an event, the probability of which is P< 1, содержит в себе информацию, и тем большую, чем меньше вероятность события, которого произошло.

Disinformation- negative value of information.

A measure of the uncertainty of events - entropy(H)

If log2 N=1 then N=2

Unit of information - bit(double unit of information)

H=lg N (hartley)

1 hartley is the amount of information needed to select one of ten equiprobable possibilities. 1 hartley = 3.3 bits

The regulator can work on compensation, when the effect on the body is a compensatory action of the regulator, which leads to the normalization of the function

Management is aimed at launching physiological functions, their correction and coordination of processes.

The most ancient is the humoral mechanism of regulation.

nervous mechanism.

neurohumoral mechanism.

The development of regulatory mechanisms leads to the fact that animals are able to move and can leave an unfavorable environment, unlike plants.

Outpost mechanism (in humans) - in the form of conditioned reflexes. On signaling stimuli, we can implement measures to influence the environment.

What is biophysics

Man seeks to know the world. In these darings man relies on science and technology. Huge radio telescopes heard the "voice" of distant galaxies, durable bathyscaphes helped discover a new world with unprecedented animals at the bottom of the ocean, powerful rockets left the sphere of gravity and opened the way to space ...

There is another "fortress" in the nature surrounding us. This is life itself. Yes, life, a living organism, a living cell - an invisible lump of protoplasm (or cytoplasm) with a nucleus enclosed in a shell - is one of the most mysterious phenomena in the world. And this "fortress" must surrender, a powerful weapon - the human mind tears the covers from the microscopic worlds of living cells, penetrating into the very essence of life.
The study of nature by man is now proceeding so rapidly and leads to such unexpected results and conclusions that they do not fit into the framework of the old sciences. For example, physics, one of the most important sciences of natural phenomena, has developed so widely that it became necessary to single out new, independent areas - quantum physics, nuclear, solid state physics, astronomical, radio physics, etc. The process of expanding and deepening human knowledge of nature has led to the emergence of such branches of science that study processes and phenomena that simultaneously belong to different fields of knowledge.
Such a frontier science, which emerged at the intersection of biology, physics and chemistry, is biophysics, which plays a special role in the study of the properties of living matter.
Biophysics is the science of physical and physico-chemical processes and their regulation in a living organism.
From biophysics, in turn, sprout new sciences that expand the horizons of human knowledge. This is how radiobiology stood out - the science of the action of various types of radiation on living organisms; space biology - a science that studies the features of life in space; mechanochemistry, which studies the mutual transformation of chemical and mechanical energy that occurs in muscle fibers; More recently, bionics has emerged, which studies living organisms in order to use the principles of their work to create new, perfect in design devices and apparatuses.
A story about these scientific disciplines included in biophysics would take up too much space, so we will only talk about the three main directions that are being developed today in biophysics, about its three departments - molecular biophysics, cellular and biophysics of control processes.
Each science, including biophysics, consists of two parts - theoretical and experimental, closely related to each other, mutually complementing each other. But there are also differences between them. Theoretical biophysics studies the primary phenomena and processes occurring in biological molecules on model substances, as scientists say, that is, on systems isolated from a living organism or artificially created. These model systems are used to study the basic processes of photosynthesis, the nature of biopotentials, bioluminescence and other phenomena.
Experimental (applied) biophysics studies the functioning of the body as a whole and its individual organs, using the methods and approaches of theoretical biophysics (biophysics of movement, vision, regulation of physiological functions).
One of the large divisions of biophysics, as already mentioned, is called molecular biophysics. This department studies the properties of biological molecules, physicochemical processes occurring in sensitive cells, their relationship with cellular structures. Particular attention is paid to the study of the properties of enzymes - proteins that have the ability to accelerate (catalyze) biochemical reactions in living organisms.
Thanks to the successes of molecular biophysics, people have learned a lot about how information is stored and transmitted in living cells, how molecules and ions move, how proteins are synthesized, how energy is stored in living cells. Molecular biophysics helps in the study of photosynthesis.
Everyone saw the green leaves of plants. But, probably, not everyone knows what amazing processes take place in an ordinary leaf of a birch or bird cherry, apple tree or wheat. The sun sends a colossal amount of energy to the Earth, which would be wasted if it were not for the green leaves that capture it, create organic matter with its help and thereby give life to all life on Earth.
This very important process takes place in green particles located in leaf cells - chloroplasts containing plant pigments - chlorophyll and carotenoids.
Portions of light energy are absorbed by pigments and produce photo-oxidation of water: it gives up its electron to the chlorophyll molecule, and then the proton is used to reduce carbon dioxide to carbohydrates. (A proton and an electron, as you know, make up a hydrogen atom; this atom is taken away in parts from a water molecule. Water is oxidized and added to carbon dioxide, and carbohydrates are obtained.) The rest of the water (it is called hydroxyl) is decomposed by special enzymes, forming oxygen, which all living things breathe.
We talked very briefly about photosynthesis. In fact, the conversion of light energy absorbed by chlorophyll into chemical energy of substances synthesized in a green leaf is an endless chain of molecular changes. During this process, electrons pass from one molecule to another, molecules of compounds with high energy are formed and decay, hundreds of thousands of reactions occur.
Biophysicists have also worked hard to unravel this process, and we owe it to molecular biophysics to elucidate its details.
One can ask the question: why do scientists struggle so long and stubbornly over the secret of the green leaf? The fact is that a green leaf is like a miniature "factory" that produces substances that form the basis of human nutrition. It has been calculated that as a raw material, green plants consume huge amounts of carbon dioxide per year - 150,000,000,000 g! If scientists unravel the great mystery of the green leaf to the end, humanity will receive the fastest and most economical way to obtain food and other important products, in a word, everything that green plants give to man today.
Molecular biophysics also deals with the processes that take place in animal organisms, for example, in their sense organs.
One of these amazing and extraordinary pages of molecular biophysics is the study of smell. Chemists have created about 1 million organic compounds, and almost all of them have their own characteristic smell. A person can distinguish several thousand odors, and for some substances extremely small quantities are enough to feel them - only millionths and billionths of a milligram per liter of water (for example, substances such as skatole, trinitrobutyl toluene, [sufficient-7-10-9 mg /l).
Animals are more sensitive than humans. Dogs, for example, distinguish about half a million different smells! They are able (especially sniffer dogs) to smell the right smell, even if it is negligibly weak. It is worth a person just a little touch to the subject - and the dog can already determine who did it. There are cases when trained sniffer dogs helped geologists find ore lying underground at a depth of 2-3 m.
But, perhaps, all are surpassed by fish and insects. Some fish feel an odorous substance at its immeasurably low content - 10 "mg / l. It's like dissolving one drop of a substance in 100 billion m3 of water! Butterflies find each other by smell at a distance of several kilometers. Calculations show that in such In the case of butterflies, they detect almost one molecule of odorous substance per 1 mg of air.How this happens remains a mystery.Some scientists suggest that odorous substances propagate electromagnetic waves, the energy of which is perceived by the sensitive cells of insects and helps them find each other on such large distances.
Recently, the attention of biophysicists has attracted the unusual ability of some species of flies. It turns out that a fly, touching a substance with its paws, instantly produces an accurate chemical analysis. The mechanism of this phenomenon is unknown, but it has been established that special sensitive cells on the paws determine the "taste" of the substance by electromagnetic means!
Molecular biophysics helps to elucidate not only the differences in the sensitivity and structure of the olfactory organs in different groups of animals, fish and insects, but also the process of smell determination itself. It has now been established that there are several basic (6-7) smells, the combinations of which explain all their diversity. These basic odors correspond to certain types of olfactory cells that perceive the smell. Cells have molecular-sized recesses of a strictly defined shape and size, corresponding to the shape of molecules of odorous substances (a camphor molecule has a likeness of a ball, a musk molecule has a disk, etc.). Getting into "its" recess, the molecule irritates the nerve endings and creates a sense of smell.
Even from a brief story it is clear that there is a close connection between the study of cells and the molecular processes occurring in them, that is, between molecular and cellular biophysics. One of them studies molecular changes, the properties of biological molecules, as well as those systems that form molecules in cells (as they say, submolecular formations), their properties and changes, and the other studies the properties and functioning of cells - excretory, contractile, olfactory, etc.
The development of cell biophysics, which we will now discuss, was greatly facilitated by the invention of the electron microscope. The use of an electron microscope with a magnification of hundreds of thousands, millions of times has greatly expanded our knowledge about the living organisms that inhabit the planet, about their internal structure. When studying a cell with an electron microscope, a new world of ultramicroscopic (the smallest) cellular structures immediately opened up. Electron microscopes made it possible to see different thicknesses of the membrane, the smallest tubes, hundreds of thousands of times thinner than a human hair, tiny bubbles, cavities, tubules. Studies have shown that even the smallest cellular structures - mitochondria, chloroplasts - also have a rather complex structure. It became clear that any cell, which seems to be a simple lump of protoplasm with a nucleus, is a complex formation with a large number of tiny cellular particles (as they say, structural elements) that act in a strict order and are interconnected in a complex, precise and coordinated manner.
The researchers were especially struck by the diversity of structural elements. For example, in a nerve cell there are up to 70 thousand particles - mitochondria, thanks to which the cell breathes and receives energy for its activities. In addition, in the cell there are up to hundreds of thousands of the smallest particles - ribosomes that create protein molecules.
The most amazing thing is that in any small cell of a living organism, exact coordinated processes take place: the absorption of necessary substances and the release of unnecessary substances take place, respiration and division take place. Along with this, the cells perform special functions: the cells of the retina determine the strength and quality of light, the cells of the nasal mucosa determine the smell of substances, the cells of various glands secrete special substances - enzymes that promote digestion, and hormones that help the growth and development of the body.
About all their great work - seen, heard, identified - cells report nerve electrical impulses to the brain - the main coordinating center. How cells receive the necessary information from the surrounding space, how this information is encrypted in electrical signals-impulses, how biological potentials are formed in cells, what is the connection with the brain - all these and many other questions are studied by cell biophysics.
Recently, an important discovery has been made in the field of cell biophysics. It has long been known that many living organisms have the ability to glow - luminescence. The glow of many inhabitants of the seas is strong - fish, sponges, stars, etc. But it turns out that the cells of any organisms have luminescence - the so-called super-weak glow. This light is so insignificant that only special devices can detect it - photomultipliers capable of amplifying the incident light flux millions of times. Superweak glow is observed in the roots and leaves of plants, in the cells of various organs of animals. Superweak glow is inherent in all cells of living organisms and occurs as a result of biochemical reactions occurring in cells.
Scientists have found that the super-weak glow has its own characteristics in various groups of animals, insects and plants. By the intensity of the ultra-weak glow, biophysicists can already now determine the drought and frost resistance of agricultural plants (barley, wheat) and thereby help plant breeders and plant physiologists in breeding the desired varieties.
We have already said that all cells are interconnected, that the reactions taking place in them, despite their complexity, proceed with amazing regularity and constancy, we also talked about the close connection of all cells with the brain. These features of cells, organs and the whole organism are studied by a recently emerged branch of science - the biophysics of control and regulation processes.
Let's talk about the work of this department on the following example. Each human organ is made up of countless cells, often performing specific jobs. For example, the nasal mucosa, the so-called olfactory epithelium, plays an important role in the sense of smell. The mucous membrane occupies an area of ​​no more than 4 s but contains almost 500 million olfactory receptor cells. Information about their work is transmitted to the olfactory nerve through nerve fibers, the number of which reaches 50 million, and then to the brain. The parts of the brain - the hemispheres of the brain - contain 2 1010 cells, and in the cerebellum there are even more of them - 10th. Even] it is difficult to imagine what kind of information flow the brain receives every second from all organs and tissues.
The signals coming from the cells in the form of primary electrical impulses must be correctly decoded, then it is necessary to make the appropriate "decisions" and transmit response signals - instructions on how certain cells, tissues or organs should work in general under certain conditions. It is clear that the central nervous system receives thousands of various signals from the external environment in the form of sounds, light, smells, etc. Thus, | we see how complex the interconnections are in any organism, how complex is the work of managing cells, regulating their state, controlling the consistency of all life processes.
This important branch of biophysics relies on the laws discovered by another science - cybernetics. Using its methods, biophysicists studying control and regulation processes have developed electronic models of living organisms, organs, cells, and even individual processes occurring in these cells. Such electronic models (for example, an electronic turtle, an electronic nerve cell, an electronic model of the photosynthesis process) facilitate the study of all | complex phenomena of regulation in a living organism.
Biophysicists who study regulation and control in a living organism have found that both cells and organs of living organisms are a system with an amazing property. Cells and organs, as biophysicists say, are SELF-regulating, SELF-organizing, SELF-adjusting, SELF-learning systems, that is, all their work, unusual qualities and properties that characterize them, the constancy of the composition of the environment inside them and the work they perform - everything is due to processes flowing in them.
In order to imagine the work of biophysicists in a little more detail, we will talk about one interesting direction that arose on the basis of biophysics and has already taken shape in an independent biophysical science - bionics.
This is a science that studies living organisms to create perfect artificial systems, machines and devices. The results of bionics research have shown that design engineers of all specialties have a lot to learn from nature. Here are some examples.
The design of modern electronic computers includes a large number of different parts (semiconductor diodes, triodes, resistances, capacitors, etc.). The dimensions of electronic computers depend on how many such parts (elements) are in 1 cm3 of the machine. The more working elements in 1 cm3 (the so-called mounting density), the more capacious the "memory" of the machine, the more opportunities to carry out the necessary operations, the better the work. It turns out that if the highest assembly density in the technical circuits of machines reaches 2000 elements in 1 cm3, then the assembly density of brain elements is 50 thousand times greater: 100,000,000 elements in 1 cm3.

The difference between living organisms and the most complex modern machines and devices is manifested not only in structure, but also in properties. Take, for example, the organs of vision. The eyes of animals are not only of different sizes - from microscopically small in an ant (0.1 mm) to giant (20-30 cm) in squids - but also differ in other properties.
It turns out that the eye of the horseshoe fish is able to increase the contrast between the edge of the visible image and the general background, so that the subject becomes sharply defined - just like they do on a TV screen, increasing or weakening the contrast. An interesting property also has the eye of an ordinary marsh frog. It is known that the frog feeds only on moving food - flies, midges, bugs. But if the insect does not move, the frog will never find its food and will remain hungry: its eye perceives only moving objects, ignoring the background.
It has long been known that nocturnal forest birds (eagle owl, owl) see perfectly in the dark, but more recently, the extraordinary ability of some animals (frogs, mice) to see even "invisible" ionizing rays - x-rays and cosmic radiation.
Nature turned out to be an exceptional designer who reached extraordinary heights of skill in the field of hearing. Experiments have shown that the human ear, by its sensitivity, is capable of perceiving sounds, the negligible intensity of which is even difficult to imagine. It can only be compared with the "noise" with which the thermal movement of molecules occurs! No less striking is the auditory organ of the grasshopper, located on its leg. This organ allows the grasshopper to feel vibrations, the magnitude of which (amplitude) is half the diameter of a hydrogen atom! The sensitivity of the grasshopper's hearing is so high that, being in Moscow, it can perceive the smallest earthquakes occurring in the Far East.
Bionics seeks to know all the unusual properties of living organisms and apply the data obtained to create machines and devices. For example, scientists are developing a device that will enable the blind to read books typed in ordinary typographic type. A model of an artificial hand has already been created, controlled by a person's thought, more precisely, by biopotentials arising in the muscles. Based on the study of the eyes of bees and dragonflies (by the way, they have a very large angle of view - 240-300 °), the designers created a device - a celestial compass used in the movement of ships and aircraft. The study of the jellyfish led to the construction of a device that warns of the onset of a storm in almost 15 hours. The list of devices developed by bionics is quite large, and even a simple listing of them would take a long time.
But bionics not only copy the functions and structure of individual animal organs. They explore and use the features of information transmission in insects, birds, and fish. The results of these works are very interesting. So, recently it became known that mosquitoes communicate with each other using electromagnetic waves of the millimeter range (13-17 mm), and the range of the mosquito "radio station" is 15 m. (for example, when a bat appears). Scientists are working on the creation of ultrasonic devices that repel harmful insects and attract beneficial ones. (See also the article "What is technical cybernetics and bionics" about bionics.)

We talked about only a small part of the research conducted by biophysicists, but much more examples could be given both in the field of studying molecules, cells, and the organism as a whole. Our century is a time of great accomplishments in all fields of knowledge, including the knowledge of living nature.

A.P. Dubov

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