Such substances like sand, clay, various minerals, water, carbon oxides, coalic acid, its salts and others, found in "inanimate nature", received the name of inorganic or minerals.
Approximately from a hundred chemical elements found in the earth's crust, only sixteen is needed for life, and four of them are hydrogen (H), carbon (C), oxygen (O) and nitrogen (N) are most common in living organisms and amount to 99%. Mass alive. The biological importance of these elements is associated with their valence (1, 2, 3, 4) and the ability to form strong covalent bonds, which are stronger than the links formed by other elements of the same valence. The following are phosphorus (P), sulfur (S), sodium, magnesium, magnesium, chlorine, potassium and calcium ions (Na, Mg, Cl, K, Ca). As trace elements in living organisms there are also iron (Fe), cobalt (CO), copper (C), zinc (Zn), Bor (B), aluminum (AL), silicon (Si), Vanadium (V), Molybdenum (V) MO), iodine (I), manganese (Mn).
All chemical elements in the form of ions or as part of certain compounds are involved in building the body. For example, carbon, hydrogen and oxygen are included in carbohydrates and fats. In the composition of proteins, nitrogen and sulfur are added to them, in the composition of nucleic acids - nitrogen, phosphorus, iron involved in the construction of the hemoglobin molecule; Magnesium is located in chlorophyll; Copper found in some oxidative enzymes; iodine is contained in thyroxine molecules (thyroid hormone); sodium and potassium provide electrical charge on the membranes of nerve cells and nerve fibers; Zinc enters the pancreas hormone molecule - insulin; Cobalt is located in vitamin B12.
Nitrogen, phosphorus, calcium compounds and other inorganic substances serve as a source of building material for the synthesis of organic molecules (amino acids, proteins, nucleic acids, etc.) and are part of a number of supporting cells of the cell and the body. Some inorganic ions (for example, calcium and magnesium ions) are activators and components of many enzymes, hormones and vitamins. With the lack of these ions, vital processes in the cell are violated.
Independent functions in living organisms perform inorganic acids and their salts. Salonic acid is part of the gastric juice of animals and a person, speeding up the process of digesting food proteins. Residues of sulfuric acid, joining insoluble in water alien substances, give them solubility, contributing to the elimination of the body. Inorganic sodium and potassium salts of nitrate and phosphoric acids are important components of plants mineral nutrition, they are added to the soil as fertilizers. Calcium and phosphorus salts are part of the bone tissue of animals. Carbon dioxide (CO2) is constantly formed in nature when oxidizing organic substances (rotting of plant and animal residues, breathing, fuel combustion) in large quantities it is released from volcanic cracks and from water mineral sources.
Water is a very common substance on Earth. Almost ѕ The surface of the globe is covered with water forming the ocean, the sea. Rivers, lakes. Many water is in a gaseous state in the form of vapors in the atmosphere; In the form of huge masses of snow and ice, it lies all year round on the tops of high mountains and in the polar countries in the depths of the Earth also contains water, impregnating the soil and rocks.
Water is very important in the life of plants, animals and humans. According to modern ideas, the origin of life is associated with the sea. In any organism, water is a medium in which chemical processes occur, which ensure the vital activity of the body; In addition, she herself takes part in a number of biochemical reactions.
The chemical and physical properties of the water are rather unusual and are mainly associated with small sizes of its molecules, with the polarity of its molecules and with their ability to connect with each other hydrogen bonds.
Consider the biological value of water. Water - superb solvent For polar substances. These include ionic compounds, such as salts, in which the charged particles (ions) are dissociated (separated from each other) in water, when the substance dissolves, as well as some non-ionic compounds, for example, sugar and simple alcohols, in the molecule of which are charged (polar) groups (sugars and alcohols it is a group). When the substance passes into the solution, its molecules or ions are able to move more freely and, accordingly, its reactivity increases. For this reason, in the cell, most of the chemical reactions occur in aqueous solutions. Non-polar substances, such as lipids, are not mixed with water and therefore can be separated by aqueous solutions into separate compartments, just as membranes are separated. Non-polar parts of molecules are repelled with water and in its presence are attracted to each other, as it happens, for example, when oil droplets merge into larger drops; In other words, non-polar hydrophobic molecules. Such hydrophobic interactions play an important role in ensuring the stability of membranes, as well as many protein molecules, nucleic acids. Inherent in the water of the solvent properties also mean that water serves as a medium for transporting various substances. It performs this role in the blood, in the lymphatic and excretory systems, in the digestive tract and in the floem and xylene of plants.
Water has big heat capacity. This means that a significant increase in thermal energy causes only a relatively slight increase in its temperature. This phenomenon is explained by the fact that a significant part of this energy is consumed on the gap of hydrogen bonds that limit the mobility of water molecules, i.e. to overcome its stickiness. The high heat capacity of water minimizes the temperature changes occurring in it. Due to this, biochemical processes flow in a smaller temperature range, with a more constant speed, and the danger of violation of these processes from sharp deviations of temperature threatens not so much. Water serves for many habitat cells and organisms for which a rather significant consistency of conditions is characteristic.
Water is characterized by a big heat evaporation. Hidden heat of evaporation (or relative hidden heat of evaporation) There is a measure of the amount of thermal energy, which is necessary to inform liquid to transition to steam, i.e. to overcome the molecular clutch forces in the liquid. Evaporation of water requires rather significant amounts of energy. This is due to the existence of hydrogen bonds between water molecules. It is precisely why the boiling point of water - substances with such small molecules - unusually high.
The energy required by water molecules for evaporation is drawn from their environment. Thus, evaporation is accompanied by cooling. This phenomenon is used in animals when sweating, with thermal shortness of mammals or some reptiles (for example, crocodiles), which are sitting with open mouth on the sun; It is possible that it plays a noticeable role in the cooling of transparency leaves. Hidden heat melting (or relative hidden melting heat) is a measure of heat energy required for melting solids (ice). Water for melting (melting) requires a relatively large amount of energy. Inversely: when freezing, water should give a large amount of thermal energy. This reduces the likelihood of freezing the contents of cells and the surrounding fluid. Ice crystals are especially destructive for living when they are formed inside the cells.
Water is the only substance possessing in a liquid state greater density than in solid. Since ice floats in water, it is formed when freezing first on its surface and only at the end in the bottom layers. If the frosting of the ponds went in the reverse order, from the bottom up, then in areas with a temperate or cold climate, life in freshwater reservoirs could not exist at all. The ice covers the thickness of the water as a blanket, which increases the chances of survival in organisms living in it. This is important in cold climate conditions and during the cold season, but, undoubtedly, it was a particularly important role in the ice age. Being on the surface, ice faster and melts. The fact that the water layers, the temperature of which fell below 4 degrees, rise up, causes their movement in large water bodies. Along with water, nutrients in it are circulated, thanks to which the reservoirs are populated by alive organisms to a greater depth.
Water is large surface tension and cohesion. Kegezia - This is the grip of the physical body molecules with each other under the action of attraction forces. There is a surface tension on the surface of the liquid - the result of cohesion forces acting between molecules inwards. Due to the surface tension, the liquid tends to take such a form so that its surface area is minimal (ideally - the shape of the ball). Of all the liquids, the largest surface tension in the water. Significant cohesion characteristic of water molecules plays an important role in living cells, as well as when the water is moving along the vessels of xylems in plants. Many small organisms benefit from surface tension for themselves: it allows them to hold on water or slide along its surface.
The biological value of water is determined by the fact that it is one of the necessary metabolites, i.e. it is involved in metabolic reactions. Water is used, for example, as a source of hydrogen in the process of photosynthesis, and also involved in hydrolysis reactions.
The role of water for living organisms is reflected, in particular, in the fact that one of the main factors of natural selection affecting the speciation is the lack of water (limiting the propagation of some plants having mobile gems). All terrestrial organisms are adapted to obtain and save water; In the extreme manifestations - in xerophytes, in the wilderness of animals, etc. This kind of adaptation is a genuine miraculous of the ingenuity of nature.
Biological functions of water:
All organisms:
1) ensures maintenance of the structure (high water content in protoplasm); 2) serves as a solvent and diffusion medium; 3) participates in hydrolysis reactions; 4) serves as a medium in which fertilization occurs;
5) Provides the spread of seeds, weights and larval stages of aquatic organisms, as well as seeds of some land plants, such as coconut palm.
At plants:
1) Causes OSMOS and TURGESSENTRATION (from which much depends on: growth (increase in cells), maintaining the structure, the movement of the Ust and T.); 2) participates in photosynthesis; 3) ensures transport of inorganic ions and organic molecules; 4) Provides germination of seeds - swelling, a break of seed peel and further development.
In animals:
1) provides transport substances;
2) causes an ocistrality;
3) contributes to the cooling of the body (sweating, thermal shortness of breath);
4) serves as one of the components of the lubricant, for example, in the joints;
5) carries the support functions (hydrostatic skeleton);
6) performs a protective function, for example, in a tear liquid and in mucus;
7) contributes to migration (sea currents).
As you know, all substances can be divided into two large categories - mineral and organic. You can learn a large number of examples of inorganic, or mineral, substances: salt, soda, potassium. But what types of compounds fall into the second category? Organic substances are represented in any living organism.
Proteins
The most important example of organic substances are proteins. They include nitrogen, hydrogen and oxygen. In addition to them, sometimes in some proteins you can also detect sulfur atoms.
Proteins are one of the most important organic compounds, and they are most often found in nature. Unlike other compounds, some characteristic features are characteristic of proteins. The main property is a huge molecular weight. For example, the molecular weight of the alcohol atom is 46, benzene - 78, and hemoglobin - 152,000. Compared to molecules of other substances, proteins are real giants containing thousands of atoms. Sometimes biologists are called their macromolecules.
Proteins are the most complex of all organic buildings. They relate to the class of polymers. If we consider the polymer molecule under the microscope, then it can be seen that it is a chain consisting of simpler structures. They are called monomers and repeated in polymers many times.
In addition to proteins, there are a large number of polymers - rubber, cellulose, as well as ordinary starch. Also, many polymers were created by both human hands - Capron, Loven, polyethylene.
Protein formation
How are proteins are formed? They are an example of organic substances, the composition of which in living organisms is determined by the genetic code. In their synthesis, various combinations are used in the overwhelming majority.
Also new amino acids can be formed when the protein begins to function in the cell. In this case, only alpha-amino acids occur in it. The primary structure of the described substance is determined by the sequence of residual amino acid compounds. And in most cases, the polypeptide chain in the formation of the protein is twisted into the spiral, the turns of which are closely close to each other. As a result of the formation of hydrogen compounds, it has a sufficiently strong structure.
Fat.
Another example of organic substances can serve fats. A lot of a lot of fats are known: butter, beef and fish oil, vegetable oils. In large quantities, fats are formed in plant seeds. If the purified sunflower seed is put on a sheet of paper and pick up, then an oily spot will remain on the sheet.
Carbohydrates
Carbohydrates are no less important. They are contained in all organs of plants. The carbohydrate class includes sugar, starch, as well as fiber. We are rich in potatoes, Banana fruits. It is very easy to detect starch in potatoes. When reaction with iodine, this carbohydrate is painted in blue. You can make sure that you can drop a little iodine into the slice of potatoes.
It is also easy to detect sugars - they all have a sweet taste. Many carbohydrates of this class are contained in the fruits of grapes, watermelons, melons, apple trees. They are examples of organic substances that are also produced in artificial conditions. For example, sugar is extracted from sugar cane.
And how are carbohydrates formed in nature? The simplest example is the process of photosynthesis. Carbohydrates are organic substances that contain a chain of several carbon atoms. Also in their composition include several hydroxyl groups. In the process of photosynthesis, the sugar of inorganic substances is formed from carbon and sulfur oxide.
Cellulose
Another example of organic substances is fiber. Most of all it is contained in cotton seeds, as well as stalks of plants and their leaves. The tissue consists of their linear polymers, its molecular weight ranges from 500 thousand to 2 million.
In their pure form, it is a substance that has no smell, taste and color. It is used in the manufacture of photographic, cellophane, explosives. In the human body, the fiber does not absorb, but is the necessary part of the diet, since it stimulates the operation of the stomach and intestines.
Organic and inorganic substances
It is possible a lot of examples of formation of organic and the second always occur from minerals - non-residential which are formed in the depths of the Earth. They come into the composition of various rocks.
In natural conditions, inorganic substances are formed in the process of destruction of minerals or organic substances. On the other hand, substances organic are constantly formed from minerals. For example, plants absorb water with compounds dissolved in it, which are later moving from one category to another. Live organisms are used to supply mainly organic matter.
Causes of diversity
Often, schoolchildren or students need to answer the question of what the causes of the diversity of organic substances are. The main factor is that carbon atoms are connected with each other with two types of connections - simple and multiple. They can also form chains. Another reason is a variety of various chemical elements that are part of organic matter. In addition, the manifold is due to the allotropy - the phenomenon of the existence of the same element in various compounds.
And how are inorganic substances formed? Natural and synthetic organic substances and their examples are studied both in high school schools and in profiled higher education institutions. The formation of inorganic substances is not such a complex process as the formation of proteins or carbohydrates. For example, soda from time immemorial people mined from soda lakes. In 1791, the Chemist Scientist Nicolas Leblan proposed to synthesize it in laboratory using chalk, salt, as well as sulfuric acid. Once all the usual soda today was a fairly expensive product. To carry out experience, it was necessary to calculate the table salt together with the acid, and then the resulting sulfate to roll together with limestone and charcoal.
Another is mangalling, or permanganate potassium. This substance is obtained in industrial conditions. The formation process consists in electrolysis of potassium hydroxide and manganese anode. In this case, the anode is gradually dissolved to form a solution of purple color - this is all known mangalls.
Little chemistry
Of the 92 chemical elements, known science at present, the 81 element is detected in the human body. Among them allocate 4 main: C (carbon), H (hydrogen), o (oxygen), n (nitrogen), as well as 8 macro- and 69 microelements.
Macroelements
Macroelements - These are substances whose content exceeds 0.005% of body weight. it Ca (calcium), Cl (chlorine), F (fluorine). K (potassium), mg (magnesium), Na (sodium), P (phosphorus) and s (sulfur). They are part of the main tissues - bones, blood, muscles. In the amount of basic and macroelements constitute 99% of human body weight.
Microelements
Microelements - These are substances that the content of which does not exceed 0.005% for each individual element, and their concentration in tissues does not exceed 0.000001%. Microelements are also very important for normal life.
A special subgroup of trace elements are ultramicroelementscontained in the body in exceptionally small quantities, it is gold, uranium, mercury, etc.
At 70-80%, the human body consists of water, the remaining fraction is organic and minerals.
Organic substances
Organic substances Can be formed (or synthesized by artificially) from mineral. The main component of all organic substances is carbon (Studying the structure, chemical properties, methods for producing and practical use of various carbon compounds is a subject of organic chemistry). Carbon It is the only chemical element capable of forming a huge number of different connections (the number of these compounds exceeds 10 million!). It is present in the composition of proteins, fats and carbohydrates that determine the nutritional value of our food; It is part of all animal organisms and plants.
In addition to carbon, organic compounds often contain oxygen, nitrogen, sometimes - phosphorus, sulfur And other elements, however, many of these compounds have the properties of inorganic. There is no sharp face between organic and inorganic substances. Basic signs of organic compounds Possess hydrocarbons - various carbon compounds with hydrogen And their derivatives. Molecules of any organic substances contain hydrocarbon fragments.
The study of various types of organic compounds discovered in living organisms, special science is engaged in their structures and properties - biochemistry.
Depending on its structure, organic compounds are divided into simple - amino acids, sugars and fatty acids, more complex - pigments, as well as vitamins and coenzymes (non-chicken components of enzymes), and the most complex - Proteinsand nucleic acids.
The properties of organic substances are determined not only by the structure of their molecules, but also the number and nature of their interactions with adjacent molecules, as well as a mutual spatial location. These factors are most pronounced in the difference in the properties of substances in different aggregate states.
The process of conversion of substances accompanied by a change in their composition and (or) structure is called chemical reaction. The essence of this process is to break the chemical bonds in the initial substances and the formation of new links in reaction products. The reaction is considered complete if the real composition of the reaction mixture no longer changes.
Reactions of organic compounds (organic reactions) obey the general laws of the flow of chemical reactions. However, their move is often more complicated than in the case of interaction of inorganic compounds. Therefore, in organic chemistry, much attention is paid to the study of reaction mechanisms.
Minerals
Mineralsin the human body less than organic, but they are also vital. These substances include iron, iodine, copper, zinc, cobalt, chrome, molybdenum, nickel, vanadium, selenium, silicon, lithium et al. Despite the low need for quantitative terms, they have an impact on the activity and speed of all biochemical processes. Without them, normal absorption of food and synthesis of hormones are impossible. With the deficiency of these substances in the human body, specific disorders arise, leading to characteristic diseases. The trace elements of children in the period of intensive growth of bones, muscles and internal organs are especially important. With age, the need for a person in minerals is somewhat reduced.
Inorganic substances are such chemical compounds that, unlike organic, do not contain carbon (except cyanides, carbides, carbonates, and some other compounds traditionally related to this group).
The classification of inorganic substances is as follows. Significant Simple substances: non-metals (H2, N2, O2), metals (Na, Zn, Fe), amphoteric Simple substances (Mn, Zn, Al), noble gases (XE, He, Rn) and complex substances: oxides (H2O, CO2, P2O5); hydroxides (Ca (OH) 2, H2SO4); Salts (CUSO4, NaCl, KnO3, Ca3 (PO4) 2) and binary connections.
Molecules of simple (single-element) substances consist only of atoms of a certain (one) view (element). They do not decompose in chemical reactions and are not capable of forming other substances. Simple substances in turn are divided into metals and non-metals. The clear boundary between them does not exist due to the ability of simple substances to show dual properties. Some elements simultaneously show properties and metals, and non-metals. They are called amphoteric.
Noble gases are inorganic substances of a separate class; They are allocated among others in particular originality. VIIIA group.
The ability of some elements to form several simple, characterized by the structure and properties is called allotropy. Examples may be elements with diamond carbines and graphite; O - ozone and oxygen; P - white, red, black and others. Such a phenomenon is possible due to the different number of atoms in the molecule and due to the ability of the formation of atoms of different crystalline forms.
In addition to ordinary basic class of inorganic substances include complex compounds. Under complex (two or multi-element) substances understand the compounds of chemical elements. Their molecules consist of atoms of different types (different elements). In case of decompositions in chemical reactions, they form several other substances. Divided by bases and salts.
In the bases, metal atoms are connected to hydroxyl groups (or one group). These compounds are divided into soluble (alkali) and insoluble in water.
Oxides consist of two elements, one of which is necessarily oxygen. They are intolerating and shaking.
Hydroxides are substances that are formed when interacting (directly or indirect) with water. These include: base (Al (OH) 3, Ca (OH) 2), acids (HCl, H2SO4, HNO3, H3PO4), (Al (OH) 3, Zn (OH) 2). In the interaction of different types of hydroxides, oxygen-containing salts are formed.
Salts are divided into medium (consist of cations and anions - Ca3 (PO4) 2, Na2SO4); acidic (containing hydrogen atoms in the acid residue, which can be replaced by cations -nahso3, CAHPO4), main (have hydro and oxo group - Cu2CO3 (OH) 2); Double (contain two different chemically cations) and / or complex (contain two different acidic residues) salts (CAMG (CO3) 2, K3).
Binary compounds (rather large class of substances) are divided into acids of oxygen-free (H2S, HCl); Salts of oxygen-free (CAF2, NaCl) and other compounds (CAC2, ALH3, CS2).
Inorganic substances do not have a carbon skeleton, which is the basis of organic compounds.
In the human body there is both (34%), so inorganic compounds. The latter include, first of all, water (60%) and calcium salts, of which the human skeleton is mainly.
Inorganic substances in the human body are represented by 22 chemical elements. Most of them are metals. Depending on the concentration of elements in the body, they are called micro (the content in the body of which is not more than 0.005% by weight of the body) and macroelements. Indispensable to the body by microelements are iodine, iron, copper, zinc, manganese, molybdenum, cobalt, chrome, selenium, fluorine. Their receipt with food in the body is necessary for its normal life. Macroelements such as calcium, phosphorus and chlorine are the basis of many tissues.
Human organism - Open biological system. The human body is a multi-level system. It consists of organ systems, each system of organs - from organs, each organ - from tissues, fabrics from cells. Each cell is a system of interconnected organelle.
The human body is an open system that is constantly exchanged by substances and energy with the environment. Oxygen comes from it to the body during gas exchange, and with food - water and nutrients. The body removes carbon dioxide, undigested residues of food, urine, sweat, secret of the sebaceous glands.
Externally, the body receives thermal energy and nutrients (proteins, fats, carbohydrates), whose molecules accumulate chemical energy. It is released in the reactions of splitting these substances in the body. Part of the chemical energy is spent on the process of its livelihoods, and excess in the form of heat is returned to the external environment.
Inorganic substances
Among all the inorganic substances, the water content in the human body is the greatest. It is up to 90% of the mass of the embryo and up to 70% of the mass of the elderly human body. Water is a solvent that provides transport substances in the body. The substances dissolved in water acquire the ability to interact. Water participates in the heat exchange processes between the organism and the environment.
The human body contains many inorganic substances. Some of them are present in the form of molecules, such as calcium compounds in the bones, substances - in the form of ions. Thus, iron ions are involved in blood oxygen transport, calcium ions are necessary to reduce muscles, and potassium and sodium ions for the formation and transfer of nerve pulses.
Organic substances
Molecules of many organic substances consist of blocks - simple organic molecules. Such a structure has all proteins. They are formed from amino acid molecules. Typically, the amino acid chain is folded into fibrous or club-like structures. So the protein molecule becomes more compact and takes less space in the cell.
In each process taking place in the body, dozens are involved, and even hundreds of various proteins. The proportion of proteins is more than 50% of the dry mass of the cells. Some proteins are a building material of cells, others work when cutting muscles, the third defend the body from infections. With the help of enzymes - protein-catalysts - almost all chemical reactions occur in the body.
Complex carbohydrates
Like I. Proteins, complex carbohydrates Food from molecules blocks. Thus, glycogen blocks are simple carbohydrate molecules - glucose. Glucose in the body plays the role of energy source, and glucose reserves are created as glycogen. In compounds with proteins and other organic substances, carbohydrates perform a structural function.
Fat.
Fat. - water insoluble organic matter. The fat molecule usually includes glycerol molecules and fatty acids. Fats form plasma membranes of cells, they accumulate in adipose tissue cells, which performs protective functions in the body. Just like glucose, fats are a source of energy. The fat molecule is more energy than the glucose molecule, but the cell produces energy from fats much longer than from carbohydrates.