It is known that the properties of organic substances are determined by their composition and chemical structure. Therefore, it is not surprising that the classification of organic compounds is based on the theory of structure - the theory of L.M. Butlerov. Organic substances are classified according to the presence and order of connection of atoms in their molecules. The most durable and least changeable part of a molecule of organic matter is its skeleton - a chain of carbon atoms. Depending on the order of joining carbon atoms in this chain, substances are divided into acyclic, which do not contain closed chains of carbon atoms in molecules, and carbocyclic, containing such values ​​(cycles) in molecules.
In addition to carbon and hydrogen atoms, molecules of organic substances can contain atoms of other chemical elements. Substances in the molecules of which these so-called heteroatoms are included in a closed chain are referred to as heterocyclic compounds.
Heteroatoms (oxygen, nitrogen, etc.) can be part of molecules and acyclic compounds, forming functional groups in them, for example, hydroxyl - OH, carbonyl, carboxyl, amino group -NH2.
Functional group- a group of atoms that determines the most characteristic chemical properties of a substance and its belonging to a certain class of compounds.

Hydrocarbons- These are compounds consisting only of hydrogen and carbon atoms.

Depending on the structure of the carbon chain, organic compounds are divided into compounds with an open chain - acyclic (aliphatic) and cyclic- with a closed chain of atoms.

Cyclics are divided into two groups: carbocyclic compounds(the cycles are formed only by carbon atoms) and heterocyclic(the cycles also include other atoms, such as oxygen, nitrogen, sulfur).

Carbocyclic compounds, in turn, include two series of compounds: alicyclic and aromatic.

Aromatic compounds at the heart of the structure of molecules have flat carbon-containing cycles with a special closed system of p-electrons that form a common π-system (a single π-electron cloud). Aromaticity is also characteristic of many heterocyclic compounds.

All other carbocyclic compounds belong to the alicyclic series.

Both acyclic (aliphatic) and cyclic hydrocarbons can contain multiple (double or triple) bonds. Such hydrocarbons are called unsaturated (unsaturated) in contrast to limiting (saturated), containing only single bonds.

Saturated aliphatic hydrocarbons are called alkanes, they have the general formula C n H 2 n +2, where n is the number of carbon atoms. Their old name is often used nowadays - paraffins.

Containing one double bond, got the name alkenes... They have the general formula C n H 2 n.

Unsaturated aliphatic hydrocarbonswith two double bonds are called alkadienes

Unsaturated aliphatic hydrocarbonswith one triple bond are called alkynes... Their general formula is C n H 2 n - 2.

Saturated alicyclic hydrocarbons - cycloalkanes, their general formula is С n Н 2 n.

A special group of hydrocarbons aromatic, or arenas(with a closed common π-electron system), is known from the example of hydrocarbons with the general formula C n H 2 n -6.

Thus, if one or more hydrogen atoms in their molecules are replaced by other atoms or groups of atoms (halogens, hydroxyl groups, amino groups, etc.), derivatives of hydrocarbons: halogen derivatives, oxygen-containing, nitrogen-containing and other organic compounds.

Halogen derivatives hydrocarbons can be considered as products of substitution in hydrocarbons of one or more hydrogen atoms by halogen atoms. In accordance with this, limiting and unsaturated mono-, di-, tri- (generally poly-) halogen derivatives can exist.

General formula of monohalogenated saturated hydrocarbons:

and the composition is expressed by the formula

C n H 2 n +1 Г,

where R is the residue from a saturated hydrocarbon (alkane), a hydrocarbon radical (this designation is used further when considering other classes of organic substances), G is a halogen atom (F, Cl, Br, I).

Alcohols- derivatives of hydrocarbons in which one or more hydrogen atoms are replaced by hydroxyl groups.

Alcohols are called monatomic, if they have one hydroxyl group, and limiting, if they are derivatives of alkanes.

The general formula of saturated monohydric alcohols:

and their composition is expressed by the general formula:
C n H 2 n +1 OH or C n H 2 n +2 O

Examples of polyhydric alcohols are known, i.e., having several hydroxyl groups.

Phenols- derivatives of aromatic hydrocarbons (benzene series), in which one or more hydrogen atoms in the benzene ring are replaced by hydroxyl groups.

The simplest representative with the formula C 6 H 5 OH is called phenol.

Aldehydes and ketones- derivatives of hydrocarbons containing a carbonyl group of atoms (carbonyl).

In the molecules of aldehydes, one bond of the carbonyl goes to compound with a hydrogen atom, the other - with a hydrocarbon radical.

In the case of ketones, the carbonyl group is linked to two (generally different) radicals.

The composition of saturated aldehydes and ketones is expressed by the formula C n H 2l O.

Carboxylic acids- derivatives of hydrocarbons containing carboxyl groups (-COOH).

If there is one carboxyl group in the acid molecule, then the carboxylic acid is monobasic. General formula of saturated monobasic acids (R-COOH). Their composition is expressed by the formula C n H 2 n O 2.

Ethers are organic substances containing two hydrocarbon radicals connected by an oxygen atom: R-O-R or R 1 -O-R 2.

Radicals can be the same or different. The composition of ethers is expressed by the formula C n H 2 n +2 O

Esters- compounds formed by replacing the hydrogen atom of the carboxyl group in carboxylic acids with a hydrocarbon radical.

Nitro compounds- derivatives of hydrocarbons in which one or more hydrogen atoms are replaced by a nitro group —NO 2.

The general formula for limiting mononitro compounds:

and the composition is expressed by the general formula

C n H 2 n +1 NO 2.

Amines- compounds considered as derivatives of ammonia (NH 3), in which hydrogen atoms are replaced by hydrocarbon radicals.

Depending on the nature of the radical, amines can be aliphaticand aromatic.

Depending on the number of hydrogen atoms replaced by radicals, the following are distinguished:

Primary amines with the general formula: R-NH 2

Secondary - with the general formula: R 1 -NH-R 2

Tertiary - with the general formula:

In a particular case, for secondary and tertiary amines, the radicals can be the same.

Primary amines can also be considered as derivatives of hydrocarbons (alkanes) in which one hydrogen atom is replaced by an amino group —NH 2. The composition of the limiting primary amines is expressed by the formula C n H 2 n +3 N.

Amino acids contain two functional groups connected to a hydrocarbon radical: amino group —NH 2, and carboxyl —COOH.

The composition of the limiting amino acids containing one amino group and one carboxyl is expressed by the formula C n H 2 n +1 NO 2.

Other important organic compounds are known that have several different or identical functional groups, long linear chains linked to benzene rings. In such cases, a strict determination of the belonging of a substance to any particular class is impossible. These compounds are often isolated into specific groups of substances: carbohydrates, proteins, nucleic acids, antibiotics, alkaloids, etc.

For the name of organic compounds, 2 nomenclatures are used - rational and systematic (IUPAC) and trivial names.

IUPAC nomenclature compilation

1) The basis of the name of the compound is the root of the word denoting a saturated hydrocarbon with the same number of atoms as the main chain.

2) A suffix is ​​added to the root, characterizing the degree of saturation:

An (limiting, there are no multiple connections);
-en (in the presence of a double bond);
-in (in the presence of a triple bond).

If there are several multiple bonds, then the number of such bonds is indicated in the suffix (-dien, -triene, etc.), and after the suffix, the position of the multiple bond must be indicated in numbers, for example:
CH 3 –CH 2 –CH = CH 2 CH 3 –CH = CH – CH 3
butene-1 butene-2

CH 2 = CH – CH = CH 2
butadiene-1,3

Such groups as nitro-, halogens, hydrocarbon radicals not included in the main chain are carried out in the prefix. However, they are listed alphabetically. The position of the substitute is indicated by a number in front of the prefix.

The order of composing the name is as follows:

1. Find the longest chain of atoms C.

2. Sequentially number the carbon atoms of the main chain, starting from the end closest to the branching.

3. The name of the alkane is made up of the names of the side radicals listed in alphabetical order, indicating the position in the main chain, and the name of the main chain.

Nomenclature of some organic substances (trivial and international)

From the guest >>

1. What is the name of an organic substance, the molecules of which contain atoms C, O, H, performing an energetic and building function?
A-nucleic acid B-protein
B-carbohydrate G-ATP
2. What carbohydrates are polymers?
A-monosaccharides B-disaccharides B-polysaccharides
3. The group of monosaccharides includes:
A-glucose B-sucrose B-cellulose
4. Which carbohydrates are water insoluble?
A-glucose, fructose B-starch B-ribose, deoxyribose
5.Fat molecules are formed:
A - from glycerin, higher carboxylic acids B - from glucose
B-of amino acids, water D-of ethyl alcohol, higher carboxylic acids
6. Fats perform functions in the cell:
A-transport B-energy
B-catalytic G-information
7. What compounds in relation to water are lipids?
A-hydrophilic B-hydrophobic
8. What is the importance of fats in animals?
A-structure of membranes B-heat regulation
B-energy source D-water source D-all of the above
9. Protein monomers are:
A-nucleotides B-amino acids B-glucose D-fats
10. The most important organic matter, which is part of the cells of all kingdoms of living nature, which has a primary linear configuration, includes:
A-to polysaccharides B-to lipids
B-c ATP G-c polypeptides
2. Write the functions of proteins, give examples.
3. Task: Along the DNA chain AATGTSGATGCTTAGTTTAGG, it is necessary to complete the complementary chain and determine the length of the DNA

1. Choose one correct answer
1. How many of the known amino acids are involved in protein synthesis?
A-20 B-100 V-23
2. What part of amino acid molecules distinguish them from each other?
A-radical B-carboxyl group B-amino group
3. What compounds are included in ATP?
A- adenine, ribose carbohydrate, 3 phosphoric acid molecules
B - guanine, fructose sugar, phosphoric acid residue.
B-ribose, glycerin and any amino acid
4. What is the role of ATP molecules in the cell?
A-provide a transport function B-transmit hereditary information
B-provide vital processes with energy D-accelerate biochemical reactions
5.Nucleic acid monomers are:
A-amino acids B-fats
B-nucleotides G-glucose
6. What class of chemical substances does ribose belong to?
A-protein B-carbohydrate B-lipid
7. What nucleotide is not included in the DNA molecule?
A-adenyl B-uridyl
B-guanyl G-thymidyl
8. Which nucleic acid is the longest?
A-DNA B-RNA
9.The guanyl nucleotide is complementary to the nucleotide:
A-thymidyl B-cytidyl
B-adenyl G-uridyl
10.The process of doubling DNA molecules is called:
A-replication B-transcription
B-complementarity G-translation.
2. Write the functions of lipids, give examples.
3. The challenge. In what sequence will the nucleotides in the i-RNA be located if the DNA chain has the following composition: GGTATAGCGCTTAAGCTTT, determine the length of the i-RNA.

Organic matter is a chemical compound that contains carbon. The only exceptions are carbonic acid, carbides, carbonates, cyanides and carbon oxides.

History

The term "organic matter" itself appeared in the everyday life of scientists at the stage of the early development of chemistry. Vitalistic worldviews prevailed at that time. This was a continuation of the traditions of Aristotle and Pliny. During this period, pundits were busy dividing the world into living and nonliving. At the same time, all substances, without exception, were clearly divided into mineral and organic. It was believed that for the synthesis of compounds of "living" substances, a special "force" was needed. It is inherent in all living things, and without it organic elements cannot form.

This assertion, ridiculous for modern science, prevailed for a very long time, until in 1828 Friedrich Wöhler empirically refuted it. He was able to obtain organic urea from inorganic ammonium cyanate. This pushed chemistry forward. However, the division of substances into organic and inorganic has been preserved in the present tense. It underlies the classification. Almost 27 million organic compounds are known.

Why are there so many organic compounds?

Organic matter is, with some exceptions, a carbon compound. This is actually a very curious element. Carbon is capable of forming chains from its atoms. At the same time, it is very important that the connection between them is stable.

In addition, carbon in organic substances exhibits a valence - IV. From this it follows that this element is capable of forming bonds with other substances not only single, but also double and triple. As their multiplicity increases, the chain of atoms will become shorter. At the same time, the stability of the connection only increases.

Also carbon has the ability to form flat, linear and three-dimensional structures. That is why there are so many different organic substances in nature.

Composition

As mentioned above, organic matter is carbon compounds. And this is very important. arise when it is associated with almost any element of the periodic table. In nature, most often their composition (in addition to carbon) includes oxygen, hydrogen, sulfur, nitrogen and phosphorus. The rest of the elements are much less common.

Properties

So, organic matter is a carbon compound. However, there are several important criteria that it must meet. All substances of organic origin have common properties:

1. The different typology of bonds existing between atoms inevitably leads to the appearance of isomers. First of all, they are formed when carbon molecules combine. Isomers are different substances with the same molecular weight and composition, but different chemical and physical properties. This phenomenon is called isomerism.

2. Another criterion is the phenomenon of homology. These are a series of organic compounds, in which the formula of neighboring substances differs from the previous ones by one CH 2 group. This important property is used in materials science.

What are the classes of organic substances?

There are several classes of organic compounds. They are known to everyone. lipids and carbohydrates. These groups can be called biological polymers. They are involved in metabolism at the cellular level in any organism. Also included in this group are nucleic acids. So we can say that organic matter is what we eat every day, what we are made of.

Squirrels

Proteins are made up of structural components - amino acids. These are their monomers. Proteins are also called proteins. About 200 types of amino acids are known. All of them are found in living organisms. But only twenty of them are constituents of proteins. They are called basic. But in the literature you can also find less popular terms - proteinogenic and protein-forming amino acids. The formula for organic matter of this class contains amine (-NH 2) and carboxyl (-COOH) components. They are connected to each other by the same carbon bonds.

Protein functions

Proteins in the body of plants and animals have many important functions. But the main one is structural. Proteins are the main components of the cell membrane and organelle matrix in cells. In our body, all walls of arteries, veins and capillaries, tendons and cartilage, nails and hair are composed mainly of different proteins.

The next function is enzymatic. Proteins act as enzymes. They catalyze the course of chemical reactions in the body. They are responsible for the breakdown of nutrients in the digestive tract. In plants, enzymes fix the position of carbon during photosynthesis.

Some carry various substances in the body, such as oxygen. Organic matter is also able to attach to them. This is how the transport function is carried out. Proteins carry metal ions, fatty acids, hormones and, of course, carbon dioxide and hemoglobin through the blood vessels. Transport also occurs at the intercellular level.

Protein compounds - immunoglobulins - are responsible for the protective function. These are blood antibodies. For example, thrombin and fibrinogen are actively involved in the clotting process. Thus, they prevent large blood loss.

Proteins are also responsible for the contractile function. Due to the fact that myosin and actin protofibrils constantly perform sliding movements relative to each other, muscle fibers contract. But unicellular organisms also have similar processes. The movement of bacterial flagella is also directly related to the sliding of microtubules, which are protein in nature.

Oxidation of organic matter releases a large amount of energy. But, as a rule, proteins are used up for energy needs very rarely. This happens when all stocks are depleted. Lipids and carbohydrates are best suited for this. Therefore, proteins can perform an energetic function, but only under certain conditions.

Lipids

A fat-like compound is also an organic matter. Lipids are among the simplest biological molecules. They are insoluble in water, but they degrade in non-polar solutions such as gasoline, ether, and chloroform. They are part of all living cells. Chemically, lipids are alcohols and carboxylic acids. The most famous of these are fats. In the body of animals and plants, these substances have many important functions. Many lipids are used in medicine and industry.

Lipid functions

These organic chemicals work with proteins in cells to form biological membranes. But their main function is energy. When fat molecules are oxidized, a huge amount of energy is released. It goes to the formation of ATP in cells. In the form of lipids, the body can store a significant amount of energy reserves. Sometimes there are even more of them than is necessary for the implementation of normal life. With pathological changes, the metabolism of "fat" cells becomes more. Although in fairness it should be noted that such excessive reserves are simply necessary for hibernating animals and plants. Many people believe that trees and shrubs feed on the soil during the cold season. In reality, they use up the reserves of oils and fats that they have made over the summer.

In humans and animals, fats can also have a protective function. They are deposited in the subcutaneous tissue and around organs such as the kidneys and intestines. Thus, they serve as good protection against mechanical damage, that is, shock.

In addition, fats have a low level of thermal conductivity, which helps to retain heat. This is very important, especially in cold climates. In marine animals, the subcutaneous fat layer also contributes to good buoyancy. But in birds, lipids also perform a water-repellent and lubricating function. The wax coats their feathers and makes them more elastic. Some plant species have the same bloom on the leaves.

Carbohydrates

The formula for organic matter C n (H 2 O) m indicates that the compound belongs to the class of carbohydrates. The names of these molecules indicate the fact that they contain oxygen and hydrogen in the same amount as water. In addition to these chemical elements, the compounds may contain, for example, nitrogen.

Carbohydrates in the cell are the main group of organic compounds. These are primary products. They are also the primary products of synthesis in plants of other substances, for example, alcohols, organic acids and amino acids. Also, carbohydrates are part of the cells of animals and fungi. They are also found among the main components of bacteria and protozoa. So, in an animal cell, they are from 1 to 2%, and in a plant cell, their number can reach 90%.

To date, only three groups of carbohydrates are distinguished:

Simple sugars (monosaccharides);

Oligosaccharides, consisting of several molecules of sequentially connected simple sugars;

Polysaccharides, they contain more than 10 molecules of monosaccharides and their derivatives.

Functions of carbohydrates

All organic substances in the cell perform specific functions. For example, glucose is the main energy source. It is broken down in all cells during cellular respiration. Glycogen and starch constitute the main store of energy, with the first substance in animals, and the second in plants.

Carbohydrates also have a structural function. Cellulose is the main component of the plant cell wall. And in arthropods, chitin performs the same function. It is also found in the cells of higher fungi. If we take oligosaccharides as an example, then they are part of the cytoplasmic membrane - in the form of glycolipids and glycoproteins. Also, glycocalyx is often detected in cells. Pentoses are involved in the synthesis of nucleic acids. When is included in DNA, and ribose is included in RNA. Also, these components are found in coenzymes, for example, in FAD, NADP and NAD.

Carbohydrates are also capable of performing a protective function in the body. In animals, the substance heparin actively prevents rapid blood coagulation. It is formed during tissue damage and blocks the formation of blood clots in the vessels. Heparin is found in large quantities in mast cells in granules.

Nucleic acids

Proteins, carbohydrates and lipids are not all known classes of organic matter. Chemistry also includes nucleic acids. These are phosphorus-containing biopolymers. They, being in the cell nucleus and cytoplasm of all living things, provide the transfer and storage of genetic data. These substances were discovered thanks to the biochemist F. Mischer, who was studying salmon spermatozoa. It was an "accidental" discovery. A little later, RNA and DNA were found in all plant and animal organisms. Were also isolated nucleic acids in the cells of fungi and bacteria, as well as viruses.

In total, two types of nucleic acids have been found in nature - ribonucleic acids (RNA) and deoxyribonucleic acids (DNA). The difference is clear from the name. deoxyribose is a five-carbon sugar. And in the RNA molecule, ribose is found.

Organic chemistry deals with the study of nucleic acids. Research topics are also dictated by medicine. There are many genetic diseases hidden in the DNA codes that scientists have yet to discover.

From the guest >>

1. What is the name of an organic substance, the molecules of which contain atoms C, O, H, performing an energetic and building function?
A-nucleic acid B-protein
B-carbohydrate G-ATP
2. What carbohydrates are polymers?
A-monosaccharides B-disaccharides B-polysaccharides
3. The group of monosaccharides includes:
A-glucose B-sucrose B-cellulose
4. Which carbohydrates are water insoluble?
A-glucose, fructose B-starch B-ribose, deoxyribose
5.Fat molecules are formed:
A - from glycerin, higher carboxylic acids B - from glucose
B-of amino acids, water D-of ethyl alcohol, higher carboxylic acids
6. Fats perform functions in the cell:
A-transport B-energy
B-catalytic G-information
7. What compounds in relation to water are lipids?
A-hydrophilic B-hydrophobic
8. What is the importance of fats in animals?
A-structure of membranes B-heat regulation
B-energy source D-water source D-all of the above
9. Protein monomers are:
A-nucleotides B-amino acids B-glucose D-fats
10. The most important organic matter, which is part of the cells of all kingdoms of living nature, which has a primary linear configuration, includes:
A-to polysaccharides B-to lipids
B-c ATP G-c polypeptides
2. Write the functions of proteins, give examples.
3. Task: Along the DNA chain AATGTSGATGCTTAGTTTAGG, it is necessary to complete the complementary chain and determine the length of the DNA
1. Choose one correct answer
1. How many of the known amino acids are involved in protein synthesis?
A-20 B-100 V-23
2. What part of amino acid molecules distinguish them from each other?
A-radical B-carboxyl group B-amino group
3. What compounds are included in ATP?
A- adenine, ribose carbohydrate, 3 phosphoric acid molecules
B - guanine, fructose sugar, phosphoric acid residue.
B-ribose, glycerin and any amino acid
4. What is the role of ATP molecules in the cell?
A-provide a transport function B-transmit hereditary information
B-provide vital processes with energy D-accelerate biochemical reactions
5.Nucleic acid monomers are:
A-amino acids B-fats
B-nucleotides G-glucose
6. What class of chemical substances does ribose belong to?
A-protein B-carbohydrate B-lipid
7. What nucleotide is not included in the DNA molecule?
A-adenyl B-uridyl
B-guanyl G-thymidyl
8. Which nucleic acid is the longest?
A-DNA B-RNA
9.The guanyl nucleotide is complementary to the nucleotide:
A-thymidyl B-cytidyl
B-adenyl G-uridyl
10.The process of doubling DNA molecules is called:
A-replication B-transcription
B-complementarity G-translation.
2. Write the functions of lipids, give examples.
3. The challenge. In what sequence will the nucleotides in the i-RNA be located if the DNA chain has the following composition: GGTATAGCGCTTAAGCTTT, determine the length of the i-RNA.

In the past, scientists divided all substances in nature into conditionally inanimate and living ones, including the kingdom of animals and plants among the latter. Substances of the first group are called mineral. And those that entered the second were called organic substances.

What does this mean? The class of organic substances is the most extensive among all chemical compounds known to modern scientists. The question of which substances are organic can be answered as follows - these are chemical compounds, which include carbon.

Please note that not all carbon-containing compounds are organic. For example, corbides and carbonates, carbonic acid and cyanides, carbon oxides are not included in their number.

Why are there so many organic substances?

The answer to this question lies in the properties of carbon. This element is curious in that it is able to form chains from its atoms. And yet the carbon bond is very stable.

In addition, in organic compounds, it exhibits a high valence (IV), i.e. the ability to form chemical bonds with other substances. And not only single, but also double and even triple (otherwise - multiples). As the multiplicity of the bond increases, the chain of atoms becomes shorter, and the stability of the bond increases.

And carbon is also endowed with the ability to form linear, flat and three-dimensional structures.

That is why organic substances in nature are so diverse. You can easily check it yourself: stand in front of a mirror and look carefully at your reflection. Each of us is a walking guide to organic chemistry. Think about it: at least 30% of the mass of each of your cells is organic compounds. The proteins that built your body. Carbohydrates that serve as a "fuel" and a source of energy. Fats that store energy stores. Hormones that control organs and even your behavior. Enzymes that trigger chemical reactions within you. And even the "source code", DNA strands are all organic carbon-based compounds.

Composition of organic substances

As we said at the very beginning, the main building material for organic matter is carbon. And almost any element, combining with carbon, can form organic compounds.

In nature, hydrogen, oxygen, nitrogen, sulfur and phosphorus are most often present in the composition of organic substances.

The structure of organic substances

The variety of organic substances on the planet and the variety of their structure can be explained by the characteristic features of carbon atoms.

Remember that carbon atoms are capable of forming very strong bonds with each other by connecting in chains. The result is stable molecules. How exactly the carbon atoms are connected in a chain (arranged in a zigzag) is one of the key features of its structure. Carbon can combine both in open chains and in closed (cyclic) chains.

It is also important that the structure of chemicals directly affects their chemical properties. The way the atoms and groups of atoms in a molecule affect each other also plays a significant role.

Due to the structural features, the account of the same type of carbon compounds goes to tens and hundreds. For example, consider hydrogen carbon compounds: methane, ethane, propane, butane, etc.

For example, methane is CH 4. Such a combination of hydrogen with carbon under normal conditions is in a gaseous state of aggregation. When oxygen appears in the composition, a liquid is formed - methyl alcohol CH 3 OH.

Not only substances with different qualitative composition (as in the example above) exhibit different properties, but substances of the same qualitative composition are also capable of this. An example is the different ability of methane CH 4 and ethylene C 2 H 4 to react with bromine and chlorine. Methane is capable of such reactions only when heated or under ultraviolet light. And ethylene reacts even without lighting and heating.

Consider this option: the qualitative composition of chemical compounds is the same, the quantitative composition is different. Then the chemical properties of the compounds are different. As is the case with acetylene C 2 H 2 and benzene C 6 H 6.

An important role in this diversity is played by such properties of organic substances, "tied" to their structure, as isomerism and homology.

Imagine that you have two seemingly identical substances - the same composition and the same molecular formula to describe them. But the structure of these substances is fundamentally different, from which follows the difference in chemical and physical properties. For example, the molecular formula C 4 H 10 can be written as two different substances: butane and isobutane.

We are talking about isomers- compounds that have the same composition and molecular weight. But the atoms in their molecules are arranged in a different order (branched and unbranched structure).

Concerning homology- this is a characteristic of such a carbon chain in which each subsequent member can be obtained by adding one CH 2 group to the previous one. Each homologous series can be expressed by one general formula. And knowing the formula, it is easy to determine the composition of any of the members of the series. For example, homologues of methane are described by the formula C n H 2n + 2.

As the "homological difference" CH 2 is added, the bond between the atoms of the substance is enhanced. Let's take the homologous series of methane: its first four members are gases (methane, ethane, propane, butane), the next six are liquids (pentane, hexane, heptane, octane, nonane, decane), and then substances in a solid state of aggregation follow (pentadecane, eicosan, etc.). And the stronger the bond between carbon atoms, the higher the molecular weight, boiling point and melting point of substances.

What classes of organic substances are there?

Organic substances of biological origin include:

• proteins;
• carbohydrates;
• nucleic acids;
• lipids.

The first three points can also be called biological polymers.

A more detailed classification of organic chemicals covers substances not only of biological origin.

Hydrocarbons include:

• acyclic compounds:
  • saturated hydrocarbons (alkanes);
  • unsaturated hydrocarbons:
    • alkenes;
    • alkynes;
    • alkadienes.
• cyclic connections:
  • carbocyclic compounds:
    • alicyclic;
    • aromatic.
  • heterocyclic compounds.

There are also other classes of organic compounds in which carbon combines with substances other than hydrogen:

• alcohols and phenols;
• aldehydes and ketones;
• carboxylic acids;
• esters;
• lipids;
• carbohydrates:
  • monosaccharides;
  • oligosaccharides;
  • polysaccharides.
  • mucopolysaccharides.
• amines;
• amino acids;
• proteins;
• nucleic acids.

Formulas of organic substances by class

Examples of organic substances

As you remember, in the human body, various kinds of organic substances are the basis of the foundations. These are our tissues and fluids, hormones and pigments, enzymes and ATP, and much more.

In the bodies of humans and animals, proteins and fats are prioritized (half of the dry mass of animal cells is proteins). In plants (approximately 80% of dry cell mass) - for carbohydrates, primarily complex ones - polysaccharides. Including cellulose (without which there would be no paper), starch.

Let's talk about some of them in more detail.

For example, about carbohydrates... If it were possible to take and measure the masses of all organic substances on the planet, it would be carbohydrates that would win this competition.

They serve as a source of energy in the body, are building materials for cells, and also carry out a supply of substances. Starch is used for this purpose for plants, glycogen for animals.

In addition, carbohydrates are very diverse. For example, simple carbohydrates. The most common monosaccharides in nature are pentoses (including deoxyribose, which is part of the DNA) and hexose (glucose you are familiar with).

As from bricks, on a large construction site of nature, polysaccharides are built from thousands and thousands of monosaccharides. Without them, or rather, without cellulose, starch, there would be no plants. And animals without glycogen, lactose and chitin would have a hard time.

Let's take a close look at proteins... Nature is the greatest master of mosaics and puzzles: from only 20 amino acids in the human body, 5 million types of proteins are formed. Proteins also have many vital functions. For example, construction, regulation of processes in the body, blood clotting (there are separate proteins for this), movement, transport of certain substances in the body, they are also a source of energy, in the form of enzymes they act as a catalyst for reactions, provide protection. Antibodies play an important role in protecting the body from negative external influences. And if discord occurs in the fine tuning of the body, antibodies, instead of destroying external enemies, can act as aggressors to the body's own organs and tissues.

Proteins are also divided into simple (proteins) and complex (proteids). And they have properties inherent only to them: denaturation (destruction, which you have noticed more than once when you boiled a hard-boiled egg) and renaturation (this property is widely used in the manufacture of antibiotics, food concentrates, etc.).

We will not ignore and lipids(fats). In our body, they serve as a reserve source of energy. As solvents, they help the course of biochemical reactions. Participate in the construction of the body - for example, in the formation of cell membranes.

And a few more words about such curious organic compounds as hormones... They are involved in biochemical reactions and metabolism. So small, hormones make men men (testosterone) and women women (estrogen). They make us happy or sad (thyroid hormones play an important role in mood swings, and endorphins give a feeling of happiness). And they even determine whether we are "owls" or "larks." Whether you are willing to study late or prefer to get up early and do your homework before school, it is not only your daily routine that decides, but also some adrenal hormones.

Conclusion

The world of organic matter is truly amazing. It is enough to delve into its study just a little to take your breath away from the feeling of kinship with all life on Earth. Two legs, four or roots instead of legs - we are all united by the magic of Mother Nature's chemical laboratory. It causes carbon atoms to chain together, react and create thousands of such diverse chemical compounds.

You now have a quick guide to organic chemistry. Of course, not all possible information is presented here. You may have to clarify some points yourself. But you can always use the route outlined by us for your independent research.

You can also use the definition of organic matter, classification and general formulas of organic compounds and general information about them given in the article to prepare for chemistry lessons in school.

Tell us in the comments which section of chemistry (organic or inorganic) you like best and why. Do not forget to “share” the article on social networks so that your classmates can use it too.

Please report if you find any inaccuracy or error in the article. We are all human and we all make mistakes sometimes.

blog. site, with full or partial copying of the material, a link to the source is required.