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Chemical elements in the human body. Organic and inorganic substances

Every day a person interacts with a large number of objects. They are made from different materials and have their own structure and composition. Everything that surrounds a person can be divided into organic and inorganic. In the article we will look at what such substances are and give examples. We will also determine what inorganic substances are found in biology.

Description

Inorganic substances are those substances that do not contain carbon. They are the opposite of organic. This group also includes several carbon-containing compounds, for example:

cyanides;
carbon oxides;
carbonates;
carbides and others.

water;
various acids (hydrochloric, nitric, sulfuric);
salt;
ammonia;
carbon dioxide;
metals and non-metals.

The inorganic group is distinguished by the absence of a carbon skeleton, which is characteristic of organic substances. According to their composition, they are usually divided into simple and complex. Simple substances make up a small group. There are approximately 400 of them in total.

Simple inorganic compounds: metals

Metals are simple atoms which are based on a metallic bond. These elements have characteristic metallic properties: thermal conductivity, electrical conductivity, ductility, luster and others. In total, there are 96 elements in this group. These include:

alkali metals: lithium, sodium, potassium;
alkaline earth metals: magnesium, strontium, calcium;
copper, silver, gold;
light metals: aluminum, tin, lead;
semimetals: polonium, moscovium, nihonium;
lanthanides and lanthanum: scandium, yttrium;
actinides and actinium: uranium, neptunium, plutonium.

Metals are mainly found in nature in the form of ores and compounds. To obtain pure metal without impurities, it is purified. If necessary, it is possible to carry out alloying or other processing. This is done by a special science - metallurgy. It is divided into black and colored.

Simple inorganic compounds: nonmetals

Nonmetals are chemical elements that do not have metallic properties. Examples of inorganic substances:

water;
nitrogen;
sulfur;
oxygen and others.

Nonmetals are characterized by a large number of electrons per their atom. This determines some properties: the ability to attach additional electrons increases, and higher oxidative activity appears.

In nature you can find non-metals in a free state: oxygen, chlorine, as well as solid forms: iodine, phosphorus, silicon, selenium.

Some nonmetals have a distinctive property - allotropy. That is, they can exist in various modifications and forms. For example:

gaseous oxygen has modifications: oxygen and ozone;
solid carbon can exist in the following forms: diamond, graphite, glassy carbon and others.

Complex inorganic compounds

This group of substances is more numerous. Complex compounds are distinguished by the presence of several chemical elements in the substance.

Let's take a closer look at complex inorganic substances. Examples and their classification are presented below in the article.

1. Oxides are compounds in which oxygen is one of the elements. The group includes:

non-salt-forming (for example, nitrogen);
salt-forming oxides (for example, sodium oxide, zinc oxide).

2. Acids are substances that contain hydrogen ions and acidic residues. For example, nitrogen hydrogen sulfide.

3. Hydroxides are compounds that contain the -OH group. Classification:

bases - soluble and insoluble alkalis - copper hydroxide, sodium hydroxide;
oxygen-containing acids - dihydrogen trioxocarbonate, hydrogen trioxonitrate;
amphoteric - chromium hydroxide, copper hydroxide.

4. Salts are substances that contain metal ions and acidic residues. Classification:

medium: sodium chloride, iron sulfide;
acidic: sodium bicarbonate, hydrosulfates;
main: dihydroxochrome nitrate, hydroxochrome nitrate;
complex: sodium tetrahydroxyzincate, potassium tetrachloroplatinate;
double: potassium alum;
mixed: potassium aluminum sulfate, potassium copper chloride.

5. Binary compounds are substances consisting of two chemical elements:

oxygen-free acids;
oxygen-free salts and others.

Inorganic compounds containing carbon

Such substances traditionally belong to the group of inorganic ones. Examples of substances:

Carbonates - esters and salts of carbonic acid - calcite, dolomite.
Carbides are compounds of non-metals and metals with carbon - beryllium carbide, calcium carbide.
Cyanides - salts of hydrocyanic acid - sodium cyanide.
Carbon oxides are a binary compound of carbon and oxygen - carbon monoxide and carbon dioxide.
Cyanates are derivatives of cyanic acid - fulmic acid, isocyanic acid.
Carbonyl metals - a complex of metal and carbon monoxide - nickel carbonyl.

All the substances considered differ in their individual chemical and physical properties. In general terms, the distinctive features of each class of inorganic substances can be identified:

1. Simple metals:

high thermal and electrical conductivity;
metallic shine;
lack of transparency;
strength and ductility;
at room temperature they retain their hardness and shape (except for mercury).

2. Simple non-metals:

simple non-metals can be in a gaseous state: hydrogen, oxygen, chlorine;
bromine occurs in the liquid state;
solid non-metals have a non-molecular state and can form crystals: diamond, silicon, graphite.

3. Complex substances:

oxides: react with water, acids and acid oxides;
acids: react with water and alkalis;
amphoteric oxides: may react with acidic oxides and bases;
hydroxides: soluble in water, have a wide range of melting points, and can change color when interacting with alkalis.

The cell of any living organism consists of many components. Some of them are inorganic compounds:

Water. For example, the amount of water in a cell ranges from 65 to 95%. It is necessary for the implementation of chemical reactions, the movement of components, and the process of thermoregulation. It is also water that determines the volume of the cell and the degree of its elasticity.
Mineral salts. They can be present in the body both in dissolved and undissolved form. An important role in cellular processes is played by cations: potassium, sodium, calcium, magnesium - and anions: chlorine, bicarbonates, superphosphate. Minerals are necessary to maintain osmotic balance, regulate biochemical and physical processes, form nerve impulses, maintain blood clotting levels and many other reactions.

Not only the inorganic substances of the cell are important for maintaining life. Organic components occupy 20-30% of its volume.

Classification:

simple organic substances: glucose, amino acids, fatty acids;
complex organic substances: proteins, nucleic acids, lipids, polysaccharides.

Organic components are necessary to perform the protective, energetic function of the cell; they serve as a source of energy for cellular activity and store nutrients, carry out protein synthesis, and transmit hereditary information.

The article examined the essence and examples of inorganic substances, their role in the composition of the cell. We can say that the existence of living organisms would be impossible without groups of organic and inorganic compounds. They are important in every area of human life, as well as in the existence of every organism.

Chemical composition of the cell

Mineral salts

water.
good solvent

Hydrophilic(from Greek hydro- water and filleo

Hydrophobic(from Greek hydro- water and Phobos

elasticity

Water. Water- universal solvent hydrophilic. 2- hydrophobic. .3- heat capacity. 4- Water is characterized 5- 6- Water provides movement of substances 7- In plants, water determines turgor support functions, 8- Water is an integral part lubricating fluids slime

Mineral salts. action potential ,

Physico-chemical properties of water as the main medium in the human body.

Of the inorganic substances that make up the cell, the most important is water. Its amount ranges from 60 to 95% of the total cell mass. Water plays a vital role in the life of cells and living organisms in general. In addition to the fact that it is part of their composition, for many organisms it is also a habitat. The role of water in a cell is determined by its unique chemical and physical properties, associated mainly with the small size of its molecules, the polarity of its molecules and their ability to form hydrogen bonds with each other.

Lipids. Functions of lipids in the human body.

Lipids are a large group of substances of biological origin, highly soluble in organic solvents such as methanol, acetone, chloroform and benzene. At the same time, these substances are insoluble or slightly soluble in water. Poor solubility is associated with the insufficient content of atoms with a polarizable electron shell, such as O, N, S or P, in lipid molecules.

The system of humoral regulation of physiological functions. Principles of hum..

Humoral physiological regulation uses body fluids (blood, lymph, cerebrospinal fluid, etc.) to transmit information. Signals are transmitted through chemicals: hormones, mediators, biologically active substances (BAS), electrolytes, etc.

Features of humoral regulation: does not have an exact addressee - with the flow of biological fluids, substances can be delivered to any cells of the body; the speed of information delivery is low - determined by the speed of flow of biological fluids - 0.5-5 m/s; duration of action.

The transmission of humoral regulation is carried out by the blood flow, lymph, by diffusion, nervous regulation is carried out by nerve fibers. The humoral signal travels more slowly (with the blood flow through the capillary at a speed of 0.05 mm/s) than the nervous signal (nerve transmission speed is 130 m/s). A humoral signal does not have such a precise addressee (it works on the principle of “everyone, everyone, everyone”) as a nervous one (for example, a nerve impulse is transmitted by the contracting muscles of a finger). But this difference is not significant, since cells have different sensitivity to chemicals. Therefore, chemicals act on strictly defined cells, that is, on those that are able to perceive this information. Cells that have such a high sensitivity to any humoral factor are called target cells.
Among humoral factors, substances with a narrow
spectrum of action, that is, directed action on a limited number of target cells (for example, oxytocin), and wider (for example, adrenaline), for which there is a significant number of target cells.
Humoral regulation is used to ensure reactions that do not require high speed and accuracy of execution.
Humoral regulation, like nervous regulation, is always carried out
a closed regulatory loop in which all elements are interconnected by channels.
As for the monitoring element of the device circuit (SP), it is absent as an independent structure in the humoral regulation circuit. The function of this link is usually performed by the endocrine system.
cell.
Humoral substances that enter the blood or lymph diffuse into the intercellular fluid and are quickly destroyed. In this regard, their effect can only extend to nearby organ cells, that is, their influence is local in nature. In contrast to local effects, distant effects of humoral substances extend to target cells at a distance.

HYPOTHALAMUS HORMONES

hormone effect

Corticoliberin - Stimulates the formation of corticotropin and lipotropin

Gonadotropin-releasing hormone - Stimulates the formation of lutropin and follitropin

Prolactoliberin - Promotes the release of prolactin

Prolactostatin - Inhibits the release of prolactin

Somatoliberin Stimulates the secretion of growth hormone

Somatostatin - Inhibits the secretion of growth hormone and thyrotropin

Thyroliberin - Stimulates the secretion of thyrotropin and prolactin

Melanoliberin - Stimulates the secretion of melanocyte-stimulating hormone

Melanostatin - Inhibits the secretion of melanocyte-stimulating hormone

ADENOGYPOPHYSIC HORMONES

STH (somatotropin, growth hormone) - Stimulates body growth, protein synthesis in cells, glucose formation and lipid breakdown

Prolactin - Regulates lactation in mammals, the instinct to nurse offspring, differentiation of various tissues

TSH (thyrotropin) - Regulates the biosynthesis and secretion of thyroid hormones

Corticotropin - Regulates the secretion of hormones from the adrenal cortex

FSH (follitropin) and LH (luteinizing hormone) - LH regulates the synthesis of female and male sex hormones, stimulates the growth and maturation of follicles, ovulation, the formation and functioning of the corpus luteum in the ovaries FSH has a sensitizing effect on follicles and Leydig cells to the action of LH, stimulates spermatogenesis

THYROID HORMONES The release of thyroid hormones is controlled by two “superior” endocrine glands. The area of the brain that connects the nervous and endocrine systems is called the hypothalamus. The hypothalamus receives information about the level of thyroid hormones and secretes substances that affect the pituitary gland. Pituitary also located in the brain in the area of a special depression - the sella turcica. It secretes several dozen hormones that are complex in structure and action, but only one of them acts on the thyroid gland - thyroid-stimulating hormone or TSH. The level of thyroid hormones in the blood and signals from the hypothalamus stimulate or inhibit the release of TSH. For example, if the amount of thyroxine in the blood is small, then both the pituitary gland and hypothalamus will know about it. The pituitary gland will immediately release TSH, which activates the release of hormones from the thyroid gland.

Humoral regulation is the coordination of the physiological functions of the human body through blood, lymph, and tissue fluid. Humoral regulation is carried out by biologically active substances - hormones that regulate body functions at the subcellular, cellular, tissue, organ and system levels and mediators that transmit nerve impulses. Hormones are produced by the endocrine glands (endocrine), as well as by the external secretion glands (tissue - the walls of the stomach, intestines, and others). Hormones affect the metabolism and activity of various organs, entering them through the blood. Hormones have the following properties: High biological activity; Specificity – effects on certain organs, tissues, cells; They are quickly destroyed in tissues; The molecules are small in size and penetrate easily through the walls of capillaries into tissues.

Adrenal glands - paired endocrine glands of vertebrates animals and person. The zona glomerulosa produces hormones called mineralcorticoids. These include :Aldosterone (basic mineralocorticosteroid hormone adrenal cortex) Corticosterone (insignificant and relatively inactive glucocorticoid hormone). Mineralcorticoids increase reabsorption Na + and K + excretion in the kidneys. In the beam zone there are formed glucocorticoids, which include: Cortisol. Glucocorticoids have an important effect on almost all metabolic processes. They stimulate education glucose from fat And amino acids(gluconeogenesis), oppress inflammatory, immune And allergic reactions, reduce proliferation connective tissue and also increase sensitivity sense organs And nervous system excitability. Produced in the mesh zone sex hormones (androgens, which are precursor substances estrogen). These sex hormones play a slightly different role than the hormones secreted gonads. Adrenal medulla cells produce catecholamines - adrenalin And norepinephrine . These hormones increase blood pressure, increase heart function, dilate the bronchial tubes, and increase blood sugar levels. When at rest, they constantly release small amounts of catecholamines. Under the influence of a stressful situation, the secretion of adrenaline and norepinephrine by the cells of the adrenal medulla increases sharply.

The resting membrane potential is a deficiency of positive electrical charges inside the cell, resulting from the leakage of positive potassium ions from it and the electrogenic action of the sodium-potassium pump.

Action potential (AP). All stimuli acting on the cell primarily cause a decrease in PP; when it reaches a critical value (threshold), an active propagating response—PD—occurs. AP amplitude approximately = 110-120 mv. A characteristic feature of AP, which distinguishes it from other forms of cell response to stimulation, is that it obeys the “all or nothing” rule, i.e., it occurs only when the stimulus reaches a certain threshold value, and a further increase in the intensity of the stimulus no longer affects amplitude, nor on AP duration. The action potential is one of the most important components of the excitation process. In nerve fibers it ensures the conduction of excitation from sensory endings ( receptors) to the body of the nerve cell and from it to the synaptic endings located on various nerve, muscle or glandular cells. The conduction of PD along nerve and muscle fibers is carried out by the so-called. local currents, or currents of action that arise between the excited (depolarized) and the resting sections of the membrane adjacent to it.

Postsynaptic potentials (PSPs) arise in areas of the membrane of nerve or muscle cells directly adjacent to synaptic terminals. They have an amplitude of the order of several mv and duration 10-15 msec. PSPs are divided into excitatory (EPSP) and inhibitory (IPSP).

Generator potentials arise in the membrane of sensitive nerve endings - receptors. Their amplitude is on the order of several mv and depends on the strength of stimulation applied to the receptor. The ionic mechanism of generator potentials has not yet been sufficiently studied.

Action potential

An action potential is a rapid change in membrane potential that occurs when nerve, muscle, and some glandular cells are excited. Its occurrence is based on changes in the ionic permeability of the membrane. In the development of an action potential, four successive periods are distinguished: local response, depolarization, repolarization and trace potentials.

Irritability is the ability of a living organism to respond to external influences by changing its physicochemical and physiological properties. Irritability manifests itself in changes in the current values of physiological parameters that exceed their shifts at rest. Irritability is a universal manifestation of the vital activity of all biosystems. These environmental changes that cause an organism's response can include a wide repertoire of reactions, ranging from diffuse protoplasmic reactions in protozoa to complex, highly specialized reactions in humans. In the human body, irritability is often associated with the property of nervous, muscle and glandular tissues to respond in the form of producing a nerve impulse, muscle contraction or secretion of substances (saliva, hormones, etc.). In living organisms that lack a nervous system, irritability can manifest itself in movements. Thus, amoebas and other protozoa leave unfavorable solutions with high salt concentrations. And plants change the position of the shoots to maximize light absorption (stretch towards the light). Irritability is a fundamental property of living systems: its presence is a classic criterion by which living things are distinguished from nonliving things. The minimum magnitude of the stimulus sufficient for the manifestation of irritability is called the perception threshold. The phenomena of irritability in plants and animals have much in common, although their manifestations in plants differ sharply from the usual forms of motor and nervous activity of animals

Laws of irritation of excitable tissues: 1) law of force– excitability is inversely proportional to the threshold force: the greater the threshold force, the less excitability. However, for excitation to occur, the force of stimulation alone is not enough. It is necessary that this irritation last for some time; 2) law of time action of the stimulus. When the same force is applied to different tissues, different durations of irritation will be required, which depends on the ability of a given tissue to manifest its specific activity, that is, excitability: the least time will be required for tissue with high excitability and the longest time for tissue with low excitability. Thus, excitability is inversely proportional to the duration of the stimulus: the shorter the duration of the stimulus, the greater the excitability. The excitability of tissue is determined not only by the strength and duration of irritation, but also by the rate (speed) of increase in the strength of irritation, which is determined by the third law - law of the rate of increase in the strength of irritation(the ratio of the strength of the stimulus to the time of its action): the greater the rate of increase in the strength of stimulation, the less excitability. Each tissue has its own threshold rate of increase in the strength of irritation.

The ability of a tissue to change its specific activity in response to irritation (excitability) is inversely dependent on the magnitude of the threshold force, the duration of the stimulus and the speed (speed) of increase in the strength of irritation.

The critical level of depolarization is the value of the membrane potential, upon reaching which an action potential occurs. The critical level of depolarization (CLD) is the level of electrical potential of the membrane of an excitable cell from which the local potential turns into an action potential.

A local response occurs to subthreshold stimuli; spreads over 1-2 mm with attenuation; increases with increasing stimulus strength, i.e. obeys the law of “force”; sums up - increases with repeated frequent subthreshold stimulation 10 - 40 mV increases.

The chemical mechanism of synaptic transmission, compared to the electrical one, more effectively provides the basic functions of the synapse: 1) one-way signal transmission; 2) signal amplification; 3) convergence of many signals on one postsynaptic cell, plasticity of signal transmission.

Chemical synapses transmit two types of signals - excitatory and inhibitory. In excitatory synapses, the neurotransmitter released from the presynaptic nerve endings causes an excitatory post-synaptic potential in the postsynaptic membrane - local depolarization, and in inhibitory synapses - an inhibitory postsynaptic potential, as a rule, hyperpolarization. The decrease in membrane resistance that occurs during an inhibitory postsynaptic potential short-circuits the excitatory postsynaptic current, thereby weakening or blocking the transmission of excitation.

Chemical composition of the cell

Organisms are made up of cells. Cells of different organisms have similar chemical compositions. About 90 elements are found in the cells of living organisms, and about 25 of them are found in almost all cells. Based on their content in the cell, chemical elements are divided into three large groups: macroelements (99%), microelements (1%), ultramicroelements (less than 0.001%).

Macroelements include oxygen, carbon, hydrogen, phosphorus, potassium, sulfur, chlorine, calcium, magnesium, sodium, iron. Microelements include manganese, copper, zinc, iodine, fluorine. Ultramicroelements include silver, gold, bromine, selenium.

A deficiency of any element can lead to illness and even death of the body, since each element plays a specific role. Macroelements of the first group form the basis of biopolymers - proteins, carbohydrates, nucleic acids, as well as lipids, without which life is impossible. Sulfur is part of some proteins, phosphorus is part of nucleic acids, iron is part of hemoglobin, and magnesium is part of chlorophyll. Calcium plays an important role in metabolism. Some of the chemical elements contained in the cell are part of inorganic substances - mineral salts and water.

Mineral salts are found in the cell, as a rule, in the form of cations (K +, Na +, Ca 2+, Mg 2+) and anions (HPO 2-/4, H 2 PO -/4, CI -, HCO 3), the ratio of which determines the acidity of the environment, which is important for the life of cells.

Of the inorganic substances in living nature, plays a huge role water.
It makes up a significant mass of most cells. A lot of water is contained in the cells of the brain and human embryos: more than 80% water; in adipose tissue cells - only 40.% By old age, the water content in cells decreases. A person who has lost 20% of water dies. The unique properties of water determine its role in the body. It is involved in thermoregulation, which is due to the high heat capacity of water - the consumption of a large amount of energy when heating. Water - good solvent. Due to their polarity, its molecules interact with positively and negatively charged ions, thereby promoting the dissolution of the substance. In relation to water, all cell substances are divided into hydrophilic and hydrophobic.

Hydrophilic(from Greek hydro- water and filleo- love) are called substances that dissolve in water. These include ionic compounds (for example, salts) and some non-ionic compounds (for example, sugars).

Hydrophobic(from Greek hydro- water and Phobos- fear) are substances that are insoluble in water. These include, for example, lipids.

Water plays an important role in the chemical reactions that occur in the cell in aqueous solutions. It dissolves metabolic products that the body does not need and thereby promotes their removal from the body. The high water content in the cell gives it elasticity. Water facilitates the movement of various substances within a cell or from cell to cell.

Inorganic compounds in the human body.

Water. Of the inorganic substances that make up the cell, the most important is water. Its amount ranges from 60 to 95% of the total cell mass. Water plays a vital role in the life of cells and living organisms in general. In addition to the fact that it is part of their composition, for many organisms it is also a habitat. The role of water in a cell is determined by its unique chemical and physical properties, associated mainly with the small size of its molecules, the polarity of its molecules and their ability to form hydrogen bonds with each other. Water as a component of biological systems performs the following essential functions: 1- Water- universal solvent for polar substances, such as salts, sugars, alcohols, acids, etc. Substances that are highly soluble in water are called hydrophilic. 2- Water does not dissolve non-polar substances and does not mix with them, since it cannot form hydrogen bonds with them. Substances that are insoluble in water are called hydrophobic. Hydrophobic molecules or parts of them are repelled by water, and in its presence they are attracted to each other. Such interactions play an important role in ensuring the stability of membranes, as well as many protein molecules, nucleic acids, and a number of subcellular structures. .3- Water has a high specific heat capacity. 4- Water is characterized high heat of vaporization, i.e. e. the ability of molecules to carry away a significant amount of heat while simultaneously cooling the body. 5- It is exclusively characteristic of water high surface tension. 6- Water provides movement of substances in the cell and body, absorption of substances and excretion of metabolic products. 7- In plants, water determines turgor cells, and in some animals performs support functions, being a hydrostatic skeleton (round and annelids, echinoderms). 8- Water is an integral part lubricating fluids(synovial - in the joints of vertebrates, pleural - in the pleural cavity, pericardial - in the pericardial sac) and slime(facilitate the movement of substances through the intestines, create a moist environment on the mucous membranes of the respiratory tract). It is part of saliva, bile, tears, sperm, etc.

Mineral salts. Modern methods of chemical analysis have revealed 80 elements of the periodic table in the composition of living organisms. Based on their quantitative composition, they are divided into three main groups. Macroelements make up the bulk of organic and inorganic compounds, their concentration ranges from 60% to 0.001% of body weight (oxygen, hydrogen, carbon, nitrogen, sulfur, magnesium, potassium, sodium, iron, etc.). Microelements are mainly ions of heavy metals. Contained in organisms in the amount of 0.001% - 0.000001% (manganese, boron, copper, molybdenum, zinc, iodine, bromine). The concentration of ultramicroelements does not exceed 0.000001%. Their physiological role in organisms has not yet been fully elucidated. This group includes uranium, radium, gold, mercury, cesium, selenium and many other rare elements. Not only the content, but also the ratio of ions in the cell is significant. The difference between the amounts of cations and anions on the surface and inside the cell ensures the occurrence action potential , what underlies the occurrence of nervous and muscle excitation.

The bulk of the tissues of living organisms inhabiting the Earth are made up of organogenic elements: oxygen, carbon, hydrogen and nitrogen, from which organic compounds are mainly built - proteins, fats, carbohydrates.

Every science is full of concepts, and if these concepts are not mastered, or indirect topics can be very difficult to learn. One of the concepts that should be well understood by every person who considers himself more or less educated is the division of materials into organic and inorganic. It doesn’t matter how old a person is, these concepts are on the list of those with the help of which they determine the general level of development at any stage of human life. In order to understand the differences between these two terms, you first need to find out what each of them is.

Organic compounds - what are they?

Organic substances are a group of chemical compounds with a heterogeneous structure, which include carbon elements, covalently linked to each other. The exceptions are carbides, coal, and carboxylic acids. Also, one of the constituent substances, in addition to carbon, are the elements of hydrogen, oxygen, nitrogen, sulfur, phosphorus, and halogen.

Such compounds are formed due to the ability of carbon atoms to form single, double and triple bonds.

The habitat of organic compounds is living beings. They can be either part of living beings or appear as a result of their vital activities (milk, sugar).

The products of the synthesis of organic substances are food, medicine, clothing items, building materials, various equipment, explosives, various types of mineral fertilizers, polymers, food additives, cosmetics and more.

Inorganic substances - what are they?

Inorganic substances are a group of chemical compounds that do not contain the elements carbon, hydrogen or chemical compounds whose constituent element is carbon. Both organic and inorganic are components of cells. The first in the form of life-giving elements, others in the composition of water, minerals and acids, as well as gases.

What do organic and inorganic substances have in common?

What could be common between two seemingly antonymous concepts? It turns out that they have something in common, namely:

Substances of both organic and inorganic origin are composed of molecules.
Organic and inorganic substances can be obtained as a result of a certain chemical reaction.

Organic and inorganic substances - what is the difference

Organic ones are better known and studied scientifically.
There are much more organic substances in the world. The number of organic ones known to science is about a million, inorganic – hundreds of thousands.
Most organic compounds are linked to each other using the covalent nature of the compound; inorganic compounds can be linked to each other using an ionic compound.
There is also a difference in the composition of the incoming elements. Organic substances consist of carbon, hydrogen, oxygen, and less commonly nitrogen, phosphorus, sulfur and halogen elements. Inorganic - consist of all elements of the periodic table, except carbon and hydrogen.
Organic substances are much more susceptible to the influence of hot temperatures and can be destroyed even at low temperatures. Most inorganic ones are less prone to the effects of extreme heat due to the nature of the type of molecular compound.
Organic substances are the constituent elements of the living part of the world (biosphere), inorganic substances are the nonliving parts (hydrosphere, lithosphere and atmosphere).
The composition of organic substances is more complex in structure than the composition of inorganic substances.
Organic substances are distinguished by a wide variety of possibilities for chemical transformations and reactions.
Due to the covalent type of bond between organic compounds, chemical reactions last slightly longer than chemical reactions in inorganic compounds.
Inorganic substances cannot be a food product for living beings; even moreover, some of this type of combination can be deadly to a living organism. Organic substances are a product produced by living nature, as well as an element of the structure of living organisms.

The human and animal body consists of organic and inorganic substances, which is determined by the form in which liquids and food products are consumed and absorbed by them.

Organic and inorganic substances have common and different properties. Inorganic substances dissolve in water and are absorbed by plants. In plants, inorganic substances change their state and turn into organic matter. This is the same chemical element, but its bonds change after it enters the plant cell from the liquid, i.e. into the structure of plant matter. Organic substances that enter the human and animal body with plant foods are identical to the chemical elements of living matter. Assimilated by the body from plant foods, chemical elements retain the natural properties of living matter, i.e. organic state.

A living organism can absorb substances from air, liquids, plant and animal foods. With air and water, a living organism receives mainly inorganic substances, which can become part of the cells of a living organism if they are not removed from it in a timely manner. Inorganic substances are absent in pure rainwater, in distilled water and in freshly prepared juices of berries, fruits and vegetables. When storing the juices of berries, fruits and vegetables, chemical elements lose their organic state and turn into inorganic substances. Only a plant has the ability to retain chemical elements in an organic state for a long time, namely until full maturity.

Inorganic compounds.

1.Water, its properties and importance for biological processes.

Water is a universal solvent. It has a high heat capacity and at the same time high thermal conductivity for liquids. These properties make water an ideal liquid for maintaining the body's thermal balance.

Due to the polarity of its molecules, water acts as a structure stabilizer.

Water is a source of oxygen and hydrogen, it is the main medium where biochemical and chemical reactions take place, the most important reagent and product of biochemical reactions.

Water is characterized by complete transparency in the visible part of the spectrum, which is important for the process of photosynthesis and transpiration.

Water practically does not compress, which is very important for giving shape to organs, creating turgor and ensuring a certain position of organs and parts of the body in space.

Thanks to water, osmotic reactions in living cells are possible.

Water is the main means of transport of substances in the body (blood circulation, ascending and descending currents of solutions throughout the plant’s body, etc.).

Minerals.

Modern methods of chemical analysis have revealed 80 elements of the periodic table in the composition of living organisms. Based on their quantitative composition, they are divided into three main groups.

Macroelements make up the bulk of organic and inorganic compounds, their concentration ranges from 60% to 0.001% of body weight (oxygen, hydrogen, carbon, nitrogen, sulfur, magnesium, potassium, sodium, iron, etc.).

Microelements are mainly ions of heavy metals. Contained in organisms in the amount of 0.001% - 0.000001% (manganese, boron, copper, molybdenum, zinc, iodine, bromine).

The concentration of ultramicroelements does not exceed 0.000001%. Their physiological role in organisms has not yet been fully elucidated. This group includes uranium, radium, gold, mercury, cesium, selenium and many other rare elements.

Role and function of individual elements.

Nitrogen in autotrophic plants is the initial product of nitrogen and protein metabolism. Nitrogen atoms are part of many other non-protein, but important compounds: pigments (chlorophyll, hemoglobin), nucleic acids, vitamins.

Phosphorus is part of many vital compounds. Phosphorus is part of AMP, ADP, ATP, nucleotides, phosphorylated saccharides, and some enzymes. Many organisms contain phosphorus in mineral form (soluble cell sap phosphates, bone tissue phosphates).

After the organisms die, phosphorus compounds are mineralized. Thanks to root secretions and the activity of soil bacteria, phosphates are dissolved, which makes it possible for phosphorus to be absorbed by plant and then animal organisms.

Sulfur is involved in the construction of sulfur-containing amino acids (cystine, cysteine), and is part of vitamin B1 and some enzymes. Sulfur and its compounds are especially important for chemosynthetic bacteria. Sulfur compounds are formed in the liver as products of the disinfection of toxic substances.

Potassium is found in cells only in the form of ions. Thanks to potassium, the cytoplasm has certain colloidal properties; potassium activates enzymes of protein synthesis, determines the normal rhythm of cardiac activity, participates in the generation of bioelectric potentials, and in the processes of photosynthesis.

Sodium (contained in ionic form) makes up a significant part of the minerals in the blood and therefore plays an important role in regulating the body’s water metabolism. Sodium ions contribute to the polarization of the cell membrane; the normal rhythm of cardiac activity depends on the presence in the nutrient medium of the required amount of sodium, potassium, and calcium salts.

Calcium in its ionic state is an antagonist of potassium. It is part of membrane structures and, in the form of salts of pectin substances, glues plant cells together. In plant cells it is often found in the form of simple, needle-shaped or fused crystals of calcium oxalate.

Magnesium is contained in cells in a certain ratio with calcium. It is part of the chlorophyll molecule, activates energy metabolism and DNA synthesis.

Iron is an integral part of the hemoglobin molecule. It is involved in the biosynthesis of chlorophyll, so when there is a lack of iron in the soil, plants develop chlorosis. The main role of iron is participation in the processes of respiration and photosynthesis by transferring electrons as part of oxidative enzymes - catalase, ferredoxin. A certain supply of iron in the body of animals and humans is stored in the iron-containing protein ferritin, contained in the liver and spleen.

Copper is found in animals and plants, where it plays an important role. Copper is part of some enzymes (oxidases). The importance of copper for the processes of hematopoiesis, the synthesis of hemoglobin and cytochromes has been established.

Every day, 2 mg of copper enters the human body with food. In plants, copper is part of many enzymes that participate in the dark reactions of photosynthesis and other biosyntheses. Animals with copper deficiency experience anemia, loss of appetite, and heart disease.

Manganese is a trace element, insufficient quantities of which cause chlorosis in plants. Manganese also plays a large role in the processes of nitrate reduction in plants.

Zinc is part of some enzymes that activate the breakdown of carbonic acid.

Boron affects growth processes, especially of plant organisms. In the absence of this microelement in the soil, conducting tissues, flowers and ovaries die off in plants.

Recently, microelements have been widely used in crop production (pre-sowing seed treatment) and in animal husbandry (microelement feed additives).

Other inorganic components of the cell are most often found in the form of salts, dissociated in solution into ions, or in an undissolved state (phosphorus salts of bone tissue, calcareous or silicon shells of sponges, corals, diatoms, etc.).

2. Basic vital compounds: proteins, carbohydrates, fats, vitamins.

Carbohydrates (saccharides). The molecules of these substances are built from only three elements - carbon, oxygen and hydrogen. Carbons are the main source of energy for living organisms. In addition, they provide organisms with compounds that are later used for the synthesis of other compounds.

The most famous and widespread carbohydrates are mono- and disaccharides dissolved in water. They crystallize and taste sweet.

Monosaccharides (monoses) are compounds that cannot be hydrolyzed. Saccharides can polymerize to form higher molecular weight compounds - di-, tri-, and polysaccharides.

Oligosaccharides. The molecules of these compounds are built from 2 to 4 molecules of monosaccharides. These compounds can also crystallize, are easily soluble in water, taste sweet, and have a constant molecular weight. Examples of oligosaccharides include the disaccharides sucrose, maltose, lactose, stachyose tetrasaccharide, etc.

Polysaccharides (polyoses) are water-insoluble compounds (form a colloidal solution) that do not have a sweet taste. Like the previous group of carbohydrates, they can be hydrolyzed (arabans, xylans, starch, glycogen). The main function of these compounds is binding, gluing together connective tissue cells, protecting cells from unfavorable factors.

Lipids are a group of compounds that are found in all living cells; they are insoluble in water. The structural units of lipid molecules can be either simple hydrocarbon chains or residues of complex cyclic molecules.

Depending on their chemical nature, lipids are divided into fats and lipoids.

Fats (triglycerides, neutral fats) are the main group of lipids. They are esters of the trihydric alcohol glycerol and fatty acids or a mixture of free fatty acids and triglycerides.

Free fatty acids are also found in living cells: palmitic, stearic, ricinic.

Lipoids are fat-like substances. They are of great importance because, due to their structure, they form clearly oriented molecular layers, and the ordered arrangement of hydrophilic and hydrophobic ends of molecules is of primary importance for the formation of membrane structures with selective permeability.

Vitamins have high physiological activity and a complex and varied chemical structure. They are necessary for normal growth and development of the body. Vitamins regulate the oxidation of carbohydrates, organic acids, amino acids, some of which are part of NAD and NADP.

Biosynthesis of vitamins is characteristic mainly of green plants. In animal organisms, only vitamins D and E are independently synthesized. Vitamins are divided into two groups: water-soluble (C, B1, B2, folic acid, B5, B12, B6, PP) and fat-soluble (A, D, E, K).

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CHEMICAL ELEMENTS IN THE HUMAN BODY (KUKUSHKIN Y. N., 1998), CHEMISTRY

For the human body, the role of about 30 chemical elements has been definitely established, without which it cannot exist normally. These elements are called vital. In addition to them, there are elements that in small quantities do not affect the functioning of the body, but at certain levels are poisons.

CHEMICAL ELEMENTS IN THE HUMAN BODY

Yu. N. KUKUSHKIN

St. Petersburg State Technological Institute

INTRODUCTION

Many chemists know the famous words spoken in the 40s of this century by the German scientists Walter and Ida Noddack, that every cobblestone on the pavement contains all the elements of the Periodic Table. At first, these words were not met with unanimous approval. However, as more and more accurate methods for the analytical determination of chemical elements were developed, scientists became increasingly convinced of the truth of these words.

If we agree that every cobblestone contains all the elements, then this should also be true for a living organism. All living organisms on Earth, including humans, are in close contact with the environment. Life requires constant metabolism in the body. The entry of chemical elements into the body is facilitated by nutrition and consumed water. In accordance with the recommendation of the Dietetic Commission of the US National Academy, the daily intake of chemical elements from food should be at a certain level (Table 1). The same number of chemical elements must be excreted from the body every day, since their contents are relatively constant.

The assumptions of some scientists go further. They believe that not only are all chemical elements present in a living organism, but each of them performs a specific biological function. It is quite possible that this hypothesis will not be confirmed. However, as research in this direction develops, the biological role of an increasing number of chemical elements is revealed.

The human body consists of 60% water, 34% organic matter and 6% inorganic matter. The main components of organic substances are carbon, hydrogen, oxygen, they also include nitrogen, phosphorus and sulfur. Inorganic substances of the human body necessarily contain 22 chemical elements: Ca, P, O, Na, Mg, S, B, Cl, K, V, Mn, Fe, Co, Ni, Cu, Zn, Mo, Cr, Si, I ,F,Se. For example, if a person weighs 70 kg, then it contains (in grams): calcium - 1700, potassium - 250, sodium - 70, magnesium - 42, iron - 5, zinc - 3.

Scientists have agreed that if the mass fraction of an element in the body exceeds 10 -2%, then it should be considered a macroelement. The proportion of microelements in the body is 10 -3 -10 -5%. If the content of an element is below 10 -5%, it is considered ultramicroelement. Of course, such a gradation is arbitrary. Through it, magnesium enters the intermediate region between macro- and microelements.

Table 1. Daily intake of chemical elements into the human body

Chemical element	Daily intake, mg
Chemical element	adults










	About 0.2 (vitamin B 12)

VITAL ELEMENTS

Undoubtedly, time will make adjustments to modern ideas about the number and biological role of certain chemical elements in the human body. In this article we will proceed from what is already reliably known. The role of macroelements that make up inorganic substances is obvious. For example, the main amount of calcium and phosphorus enters the bones (calcium hydroxyphosphate Ca 10 (PO 4) 6 (OH) 2), and chlorine in the form of hydrochloric acid is found in gastric juice.

Microelements are included in the above-mentioned series of 22 elements that are necessarily present in the human body. Note that most of them are metals, and of the metals more than half are d-elements. The latter form coordination compounds in the body with complex organic molecules. Thus, it has been established that many biological catalysts - enzymes contain transition metal ions ( d-elements). For example, it is known that manganese is part of 12 different enzymes, iron - in 70, copper - in 30, and zinc - in more than 100. Microelements are called vital if their absence or deficiency disrupts the normal functioning of the body. A characteristic feature of the required element is the bell-shaped appearance of the dose curve ( n) - responsiveness ( R, effect) (Fig. 1).

Rice. 1. Response dependence ( R) from dose ( n) for vital elements

With a small intake of this element, significant damage is caused to the body. He functions on the edge of survival. This is mainly due to a decrease in the activity of enzymes that contain this element. As the dose of the element increases, the response increases and reaches the norm (plateau). With a further increase in the dose, the toxic effect of an excess of this element appears, as a result of which a fatal outcome cannot be ruled out. The curve in Fig. 1 can be interpreted as follows: everything should be in moderation and very little and very much are harmful. For example, a lack of iron in the body leads to anemia, since it is part of the hemoglobin in the blood, or rather, its component - heme. An adult's blood contains about 2.6 g of iron. In the process of life, the body constantly breaks down and synthesizes hemoglobin. To replenish the iron lost with the breakdown of hemoglobin, a person needs an average daily intake of about 12 mg of this element from food. The connection between anemia and iron deficiency has been known to doctors for a long time, since back in the 17th century in some European countries an infusion of iron filings in red wine was prescribed for anemia. However, excess iron in the body is also harmful. It is associated with siderosis of the eyes and lungs - diseases caused by the deposition of iron compounds in the tissues of these organs. The main regulator of iron content in the blood is the liver.

A lack of copper in the body leads to the destruction of blood vessels, pathological bone growth, and defects in connective tissues. In addition, copper deficiency is believed to be one of the causes of cancer. In some cases, doctors associate lung cancer in older people with an age-related decrease in copper content in the body. However, excess copper in the body leads to mental disorders and paralysis of some organs (Wilson's disease). Only relatively large amounts of copper compounds are harmful to humans. In small doses they are used in medicine as an astringent and bacteriostasis (inhibiting the growth and reproduction of bacteria) agent. For example, copper (II) sulfate is used in the treatment of conjunctivitis in the form of eye drops (25% solution), as well as for cauterization for trachoma in the form of eye pencils (an alloy of copper (II) sulfate, potassium nitrate, alum and camphor) . In case of skin burns with phosphorus, the skin is thoroughly moistened with a 5% solution of copper (II) sulfate.

Table 2. Characteristic symptoms of deficiency of chemical elements in the human body

Element deficiency	Typical symptom
	Slower skeletal growth
	Muscle cramps
	Anemia, immune system disorder
	Skin damage, slowed growth, delayed puberty
	Arterial weakness, liver dysfunction, secondary anemia
	Infertility, deterioration of skeletal growth
	Slow cell growth, susceptibility to caries
	Pernicious anemia
	Increased incidence of depression, dermatitis
	Diabetes symptoms
	Skeletal growth disorder
	Dental caries
	Thyroid dysfunction, slow metabolism
	Muscular (particularly cardiac) weakness

The biological function of other alkali metals in a healthy body is still unclear. However, there are indications that by introducing lithium ions into the body it is possible to treat one of the forms of manic-depressive psychosis. Let's give a table. 2, from which the important role of other vital elements is visible.

IMPURITY ELEMENTS

There are a large number of chemical elements, especially heavy ones, which are poisons for living organisms - they have adverse biological effects. In table 3 shows these elements in accordance with the Periodic Table of D.I. Mendeleev.

Table 3.

Period	Group
Period

With the exception of beryllium and barium, these elements form strong sulfide compounds. There is an opinion that the reason for the action of poisons is associated with the blocking of certain functional groups (in particular, sulfhydryl groups) of the protein or with the displacement of metal ions, such as copper and zinc, from certain enzymes. The elements presented in table. 3 are called impurities. Their dose-response diagram has a different shape compared to life-saving (Fig. 2).

Rice. 2. Response dependence ( R) from dose ( n) for impurity chemical elements Up to a certain content of these elements, the body does not experience any harmful effects, but with a significant increase in concentration they become toxic.

There are elements that are poisonous in relatively large quantities, but have a beneficial effect in low concentrations. For example, arsenic, a strong poison that disrupts the cardiovascular system and affects the kidneys and liver, is beneficial in small doses, and doctors prescribe it to improve appetite. Oxygen, which a person needs for breathing, in high concentrations (especially under pressure) has a toxic effect.

From these examples it is clear that the concentration of the element in the body plays a very significant, and sometimes catastrophic, role. Among the impurity elements there are also those that in small doses have effective healing properties. Thus, the bactericidal (causing the death of various bacteria) property of silver and its salts was noticed long ago. For example, in medicine, a solution of colloidal silver (collargol) is used to wash purulent wounds, the bladder, for chronic cystitis and urethitis, as well as in the form of eye drops for purulent conjunctivitis and blennorrhea. Silver nitrate pencils are used to cauterize warts and granulations. In diluted solutions (0.1-0.25%), silver nitrate is used as an astringent and antimicrobial agent for lotions, and also as eye drops. Scientists believe that the cauterizing effect of silver nitrate is associated with its interaction with tissue proteins, which leads to the formation of protein salts of silver - albuminates. Silver is not yet classified as a vital element, but its increased content in the human brain, endocrine glands, and liver has already been experimentally established. Silver enters the body through plant foods, such as cucumbers and cabbage.

The article presents the Periodic Table, in which the bioactivity of individual elements is characterized. The assessment is based on the manifestation of symptoms of deficiency or excess of a particular element. It takes into account the following symptoms (in order of increasing effect): 1 - loss of appetite; 2 - need to change diet; 3 - significant changes in tissue composition; 4 - increased damage to one or more biochemical systems, manifested under special conditions; 5 - incapacity of these systems in special conditions; 6 - subclinical signs of incapacity; 7 - clinical symptoms of incapacity and increased damage; 8 - inhibited growth; 9 - lack of reproductive function. The extreme form of manifestation of deficiency or excess of an element in the body is death. The bioactivity of the element was assessed on a nine-point scale depending on the nature of the symptom for which specificity was identified.

With this assessment, vital elements are characterized by the highest score. For example, the elements hydrogen, carbon, nitrogen, oxygen, sodium, magnesium, phosphorus, sulfur, chlorine, potassium, calcium, manganese, iron, etc. are characterized by a score of 9.

CONCLUSION

Identifying the biological role of individual chemical elements in the functioning of living organisms (humans, animals, plants) is an important and exciting task. Minerals, like vitamins, often act as coenzymes to catalyze chemical reactions that occur all the time in the body.

The efforts of specialists are aimed at revealing the mechanisms of manifestation of the bioactivity of individual elements at the molecular level (see articles by N.A. Ulakhnovich “Metal complexes in living organisms”: Soros Educational Journal. 1997. No. 8. P. 27-32; D.A. Lemenovsky "Compounds of metals in living nature": Ibid. No. 9. P. 48-53). There is no doubt that in living organisms, metal ions are found mainly in the form of coordination compounds with “biological” molecules that act as ligands. Due to space limitations, the article contains material related mainly to the human body. Clarifying the role of metals in the life of plants will undoubtedly be useful for agriculture. Work in this direction is widely carried out in laboratories in various countries.

A very interesting question is about the principles of nature’s selection of chemical elements for the functioning of living organisms. There is no doubt that their prevalence is not a decisive factor. A healthy body itself is able to regulate the content of individual elements. Given a choice (food and water), animals can instinctively contribute to this regulation. The capabilities of plants in this process are limited. Conscious regulation by humans of the content of microelements in the soil of agricultural land is also one of the important tasks facing researchers. The knowledge acquired by scientists in this direction has already formed into a new branch of chemical science - bioinorganic chemistry. Therefore, it is appropriate to recall the words of the outstanding scientist of the 19th century A. Ampere: “Happy are those who develop science in the years when it is not completed, but when a decisive turn is already ripe in it.” These words can be especially useful to those who are faced with choosing a profession.

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Yuri Nikolaevich Kukushkin, Doctor of Chemical Sciences, Professor, Head. Department of Inorganic Chemistry of the St. Petersburg State Technological Institute, Honored Scientist of the Russian Federation, laureate of the Prize named after. L.A. Chugaev of the USSR Academy of Sciences, academician of the Russian Academy of Natural Sciences. Area of scientific interests: coordination chemistry and chemistry of platinum metals. Author and co-author of more than 600 scientific articles, 14 monographs, textbooks and popular science books, 49 inventions.