Organic substances. All about organic matter

ORGANIC CHEMISTRY

Textbook for students of specialties 271200 “Technology of food products for special purposes and public catering”, 351100 “Commodity research and examination of goods”

Introduction

Human use of organic substances and their extraction from natural sources has been dictated by practical needs since ancient times.

As a special branch of science, organic chemistry arose at the beginning of the 19th century and has now achieved quite a high level development. Of the huge number of chemical compounds, most (over 5 million) contain carbon, and almost all of them are organic substances. Most organic compounds are substances obtained using new scientific methods. Natural compounds today are sufficiently studied substances and find new areas of application in human life support.

Currently there is practically no industry National economy, not related to organic chemistry: medicine, pharmacology, electronic technology, aviation and space, light and food industries, agriculture, etc.

An in-depth study of natural organic substances, such as fats, carbohydrates, proteins, vitamins, enzymes and others, has opened up the possibility of interfering with metabolic processes, offering balanced nutrition, and regulating physiological processes. Modern organic chemistry, thanks to insight into the mechanisms of reactions occurring during storage and processing of food products, has made it possible to control them.

Organic substances have found application in the production of most consumer goods, in technology, in the production of dyes, cultural goods, perfumes, the textile industry, etc.

Organic chemistry is an important theoretical basis for the study of biochemistry, physiology, food technology, commodity science, etc.

Classification of organic compounds

All organic compounds are divided according to the structure of the carbon skeleton:

1. Acyclic (aliphatic) compounds, having an open carbon chain, both straight and branched.

2-methylbutane

stearic acid

2. Carbocyclic compounds- these are compounds containing rings of carbon atoms. They are divided into alicyclic and aromatic.

Alicyclic compounds include compounds with a cyclic structure that do not have aromatic properties.

cyclopentane

Aromatic substances include substances containing a benzene ring in the molecule, for example:
toluene

3. Heterocyclic compounds– substances containing cycles consisting of carbon atoms and heteroatoms, for example:

furan pyridine

The compounds of each section are in turn divided into classes, which are derivatives of hydrocarbons, in their molecules hydrogen atoms are replaced by various functional groups:

halogen derivatives CH 3 –Cl; alcohols CH 3 –OH; nitro derivatives CH 3 –CH 2 –NO 2; amines CH 3 –CH 2 –NH 2; sulfonic acids CH 3 –CH 2 –SO 3 H; aldehydes CH 3 –HC=O; carboxylic acids
and others.

Functional groups define Chemical properties organic compounds.

Depending on the number of hydrocarbon radicals associated with a particular carbon atom, the latter is called primary, secondary, tertiary and quaternary.

Classes of organic compounds

Isomerism

Isomerism- this is a phenomenon when substances, having the same quantitative and high-quality composition, differ in structure, physical and chemical properties.

Types of isomerism:

1. Structural isomerism:

a) Isomerism of the carbon skeleton.

2-methylpropane (isobutane)

b) Isomerism of the position of a double (triple) bond.

1-butene 2-butene

c) Isomerism of the position of the functional group.

1-propanol 2-propanol

2. Stereoisomerism (spatial):

a) Geometric: cis-, trans-isomerism. It is caused by different spatial arrangements of substituents relative to the plane of the double bond; occurs due to the lack of rotation around the double bond.

cisbutene-2 ​​transbutene-2

b) Optical or mirror isomerism is a type of spatial isomerism (stereoisomerism), depending on the asymmetry of the molecule, i.e. from the spatial arrangement of four different atoms or groups of atoms around an asymmetric carbon atom. Optic isomers (stereoisomers) are related to each other as an object is to its mirror image. Such optical isomers are called antipodes, and their mixtures in equal quantities of both are called racemic mixtures. In this case, they are optically inactive substances, since each of the isomers rotates the plane of polarization of light in the opposite direction. Lactic acid has 2 anitipods, the number of which is determined by the formula 2 n = number of isomers, where n is the number of asymmetric carbon atoms.

Many organic matter(hydroxy acids) are optically active substances. Each optically active substance has its own specific rotation of polarized light.

The fact of optical activity of substances applies to all organic substances containing asymmetric carbon atoms (hydroxy acids, carbohydrates, amino acids, etc.).

Video tutorial:

Lecture: Classification of organic substances. Nomenclature of organic substances (trivial and international)

Classification of organic substances

The classification of organic substances is based on the theory of A.M. Butlerov. The table shows the classification of organic substances depending on the type of carbon chain structure, i.e. by type of carbon skeleton:

Acyclic compounds- these are organic substances in the molecules of which carbon atoms are connected to each other in straight and also branched open chains.

For example, ethane is acyclic:

or acetylene:

Otherwise, such compounds are called aliphatic or fatty compounds, because the first compounds of this series of organic substances were obtained from vegetable or animal fats. Acyclic compounds include:

Limit (or saturated) - these compounds contain in the carbon skeleton single covalent nonpolar carbon-carbon C-C and weakly polar S-N connections, This alkanes.

The general molecular formula of alkanes is C n H 2n+2, where n is the number of carbon atoms in a hydrocarbon molecule. These include open chains as well as closed (cyclic) hydrocarbons. All carbon atoms in alkanes have sp 3 - hybridization. Remember the following alkanes:

Methane - CH 4

Ethane - C 2 H 6: CH 3 -CH 3

Propane - C 3 H 8: CH 3 -CH 2 -CH 3

Butane - C 4 H 10: CH 3 -(CH 2) 2 -CH 3

Pentane - C 5 H 12: CH 3 -(CH 2) 3 -CH 3

Hexane - C 6 H 14: CH 3 -(CH 2) 4 -CH 3

Heptane - C 7 H 16: CH 3 -(CH 2) 5 -CH 3

Octane - C 8 H 18: CH 3 -(CH 2) 6 -CH 3

Nonane - C 9 H 20: CH 3 -(CH 2) 7 -CH 3

Decane - C 10 H 22: CH 3 -(CH 2) 8 -CH 3

Unsaturated (or unsaturated) - contain multiple - double (C=C) or triple (C≡C) bonds, these are alkenes, alkynes and alkadienes:

1) Alkens- contain one carbon-carbon bond, which is a double C=C. General formula - CnH2n.The carbon atoms in these compounds have sp 2 - hybridization. The C=C bond has a π bond and a σ bond, so alkenes are more reactive than alkanes. Remember the following alkenes:

Ethene (ethylene) - C 2 H 4: CH 2 =CH 2

Propene (propylene) - C 3 H 6: CH 2 = CH-CH 3

Butene - C 4 H 8: butene-1 CH 3 -CH 2 -CH=CH, butene-2 ​​CH 3 -CH=CH-CH 3, isobutene [CH 3 ] 2 C=CH 2

Penten - C 5 H 10: 1-pentene CH 3 -CH 2 -CH 2 -CH=CH 2, 2-pentene C 2 H 5 CH=CHCH 3

Hexene - C 6 H 12: 1-hexene CH 2 =CH-CH 2 -CH 2 -CH 2 -CH 3, cis - hexene-2 ​​CH 3 -CH=CH-CH 2 -CH 2 -CH 3 and other isomers.

Heptene - C 7 H 14: 1-heptene CH 2 =CH-CH 2 -CH-CH 2 -CH 2 -CH 3, 2-heptene CH 3 -CH=CH-CH 2 -CH 2 -CH 2 -CH 3 and etc.

Octene - C 8 H 16: 1-octene CH 2 =CH-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3, 2-octene CH 3 -CH=CH-CH 2 -CH 2 -CH 2 -CH 2 -CH 3 etc.

Nonene - C 9 H 18: 3-nonene CH 3 -CH 2 -CH=CH-CH 2 -CH 2 -CH 2 -CH 2 -CH 3, 5-nonene CH 3 -CH 2 -CH 2 -CH 2 - CH=CH-CH 2 -CH 2 -CH 3 etc.

Decene - C 10 H 20: 2-decene CH 3 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH=CH-CH 3, etc.

As you noticed, the names of alkenes are similar to the names of alkanes, with a difference in the suffix. The names of alkanes have the suffix -ane, and alkenes have the suffix -ene. In addition, among the listed alkenes there is no methene. Remember, methane does not exist because methane only has one carbon. And for the formation of alkenes, the formation of double bonds is necessary.

The location of the double bond is indicated by a number, for example, 1-butene: CH 2 =CH–CH 2 –CH 3 or 1-hexene: CH 3 –CH 2 –CH 2 –CH 2 –CH=CH 2. Please note this rule: the numbering of hydrocarbon chains should be done so that the double bonds are at the lowest number, for example, 2-hexene:

2) Alkins– the molecules contain one triple C≡C bond. General formula - CnH2n-2. IN names of alkynes the suffix -an is replaced by -in. For example, 3-heptine: CH 3 –CH 2 –CH 2 –C≡C–CH 2 –CH 3. For ethyne HC≡CH, the trivial name acetylene is also possible. The position of the triple bond is indicated in the same way as in the previous case with alkenes. If there is more than one triple bond in a compound, then the suffix -diyne or -triyne is added to the name. If the compound contains both double and triple bonds, then their numbering is determined by the double bond, therefore, they are called first double, then triple bonds. For example, hexadiene-1,3-in-5: CH 2 =CH–CH2 =CH2 –C≡CH.

3) Alcadienes – the molecules contain two double C=C bonds. General formula - CnH2n-2,the same as for alkynes. Alkynes and alkadienes belong to interclass isomers.For example, 1,3-butadiene or divinyl C 4 H 6: CH 2 =CH-CH=CH2.

Cyclic connections- This organic matter, the molecules of which contain three or more atoms connected in a closed ring, forming cycles.

Saturated cyclic hydrocarbons are called cycloalkanes. Them about general formula - CnH 2n. Molecules contain a closed chain or rings. For example, cyclopropane (C 3 H 6):

and cyclobutane (C 4 H 8):

Depending on which atoms formed the cycles, this type compounds are divided into carbocyclic and heterocyclic.

Carbocyclic , which are otherwise called homocyclic, contain only carbon atoms in the cycles. In turn, they are divided into aliphatic and aromatic.

Alicyclic (aliphatic) compounds differ in that carbon atoms can be connected to each other into straight, branched chains or rings using single, double or triple bonds.

A typical aliphatic compound is cyclohexene:

Aromatic compounds got their name due to the aromatic smell of the substance. Otherwise called arenas. They are distinguished by the presence of a benzene ring in the compound:

There may be several such rings in the composition. For example, naphthalene:

Also this group compounds contains an aromatic system, which characterizes the high stability and stability of the compound. An aromatic system contains 4n+2 electrons in the ring (where n = 0, 1, 2, ...). This group of organic substances tends to undergo substitution reactions rather than addition reactions.

Aromatic compounds may have a functional group attached directly to the ring. For example, toluene:

Heterocyclic compounds always contain in the hydrocarbon cycle one or more heteroatoms, which are oxygen, nitrogen or sulfur atoms. If there are five heteroatoms, then the compounds are called five-membered, if there are six, then six-membered. An example of a heterocyclic compound is pyridine:

Classification of hydrocarbon derivatives

Other organic substances are considered exclusively as derivatives of hydrocarbons, which are formed when functional groups that include other chemical elements are introduced into hydrocarbon molecules. The formula of compounds having one functional group can be written as R-X. Where R is a hydrocarbon radical (a fragment of a hydrocarbon molecule without one or more hydrogen atoms; X is a functional group. Based on the presence of functional groups, hydrocarbons are divided into:

Halogen derivatives - judging by the name, it is clear that in these compounds the hydrogen atoms are replaced by atoms of some halogen.

Alcohols and phenols. In alcohols, the hydrogen atoms are replaced by a hydroxyl group -OH. According to the number of such groups, alcohols are divided into monohydric and polyatomic, including diatomic, triatomic, etc.

Formula of monohydric alcohols: CnH2n+1OH or CnH2n+2O.

Formula polyhydric alcohols: C n H 2n +2O x; x is the atomicity of the alcohol.

Alcohols can also be aromatic. Formula of monohydric aromatic alcohols: CnH2n-6O.

It should be remembered that derivatives of aromatic hydrocarbons in which one/several hydrogen atoms are replaced by hydroxyl groups do not belong to alcohols. This type belong to the class of phenols. The reason why phenols are not classified as alcohols is due to their specific chemical properties. Monohydric phenols are isomeric to monohydric aromatic alcohols. That is, they also have a common molecular formula CnH2n-6O.

Amines- ammonia derivatives in which one, two or three hydrogen atoms are replaced by a hydrocarbon radical. Amines in which only one hydrogen atom is replaced by a hydrocarbon radical, that is, having the general formula R-NH 2 , are called primary amines. Amines in which two hydrogen atoms are replaced by hydrocarbon radicals are called secondary. Their formula is R-NH-R'. It should be remembered that the radicals R and R’ can be either the same or different. If all three hydrogen atoms of the ammonia molecule are replaced by a hydrocarbon radical, then the amines are tertiary. In this case, R, R’, R’’ can be either completely identical or different. The general formula of primary, secondary and tertiary saturated amines is CnH2n+3N. Aromatic amines with one unsaturated substituent have the formula CnH2n-5N.

Aldehydes and ketones. In aldehydes, at the primary carbon atom, two hydrogen atoms are replaced by one oxygen atom. That is, their structure contains an aldehyde group – CH=O. General formula - R-CH=O. In ketones, at the secondary carbon atom, two hydrogen atoms are replaced by an oxygen atom. That is, these are compounds whose structure contains a carbonyl group –C(O)-. General formula of ketones: R-C(O)-R’. In this case, the radicals R, R’ can be either the same or different. Aldehydes and ketones are quite similar in structure, but they are still distinguished as classes, since they have significant differences in chemical properties. The general formula of saturated ketones and aldehydes is: CnH2nO.

Carboxylic acids contain a carboxyl group –COOH. When an acid contains two carboxylic groups, the acid is called a dicarboxylic acid. Saturated monocarboxylic acids (with one -COOH group) have the general formula - CnH2nO 2 . Aromatic monocarboxylic acids have the general formula CnH2n-8O 2 .

Ethers– organic compounds in which two hydrocarbon radicals are indirectly connected through an oxygen atom. That is, they have a formula like: R-O-R'. In this case, the radicals R and R’ can be either the same or different. Formula of limiting ethers - CnH2n+1OH or C n H 2n +2O.

Esters– a class of compounds based on organic carboxylic acids in which the hydrogen atom in the hydroxyl group is replaced by a hydrocarbon radical R.

Nitro compounds – derivatives of hydrocarbons in which one or more hydrogen atoms are replaced by a nitro group –NO 2. Saturated nitro compounds with one nitro group have the formula C n H 2n +1NO 2 .

Amino acids have two functional groups in their structure at the same time - amino NH 2 and carboxyl - COOH. For example: NH 2 -CH 2 -COOH. Saturated amino acids having one carboxyl and one amino group are isomeric to the corresponding saturated nitro compounds, that is, they have the general formula C n H 2n +1NO 2 .

Nomenclature of organic compounds

The connection nomenclature is divided into 2 types:

trivial and

systematic.

Trivial is historically the first nomenclature that arose at the very beginning of the development of organic chemistry. The names of the substances were associative in nature, for example, oxalic acid, urea, indigo.

Creation of a systematic, i.e. international nomenclature began in 1892. Then the Geneva nomenclature was started, which from 1947 to this day has been continued by IUPAC (IUPAC - the international unified chemical nomenclature). According to systematic nomenclature, the names of organic compounds are composed of the root indicating the length of the main chain, i.e. carbon atoms connected in an unbranched chain, as well as prefixes and suffixes indicating the presence and location of substituents, functional groups and multiple bonds.

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 an organic substance molecule is its skeleton - a chain of carbon atoms. Depending on the order of connection of carbon atoms in this chain, substances are divided into acyclic, which do not contain closed chains of carbon atoms in molecules, and carbocyclic, which contain such chains (cycles) in molecules.
In addition to carbon and hydrogen atoms, molecules of organic substances can contain atoms of other chemical elements. Substances in whose molecules these so-called heteroatoms are included in a closed chain are classified 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 open-chain compounds - acyclic (aliphatic) and cyclic- with a closed chain of atoms.

Cyclic ones are divided into two groups: carbocyclic compounds(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 based on the molecular structure have flat carbon-containing rings with a special closed system p-electrons forming 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 saturated (saturated), containing only single bonds.

Saturated aliphatic hydrocarbons 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 today - 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 called alkadienes

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

Saturated alicyclic hydrocarbons - cycloalkanes, their general formula is C n H 2 n.

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

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

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

General formula of monohalogen derivatives of saturated hydrocarbons:

and the composition is expressed by the formula

C n H 2 n +1 G,

where R is the remainder of 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.

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

There are known examples of polyhydric alcohols, that is, those with 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 aldehyde molecules, one carbonyl bond connects with a hydrogen atom, the other with a hydrocarbon radical.

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

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

Carboxylic acids- hydrocarbon derivatives containing carboxyl groups (-COOH).

If there is one carboxyl group in an 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.

General formula of saturated mononitro compounds:

and the composition is expressed by the general formula

C n H 2 n +1 NO 2 .

Amines- compounds that are 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-NNH 2

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

Tertiary - with the general formula:

In a particular case, secondary and tertiary amines may have the same radicals.

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 saturated 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: an amino group -NH 2, and a carboxyl -COOH.

The composition of saturated 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 connected to benzene rings. In such cases, a strict determination of whether a substance belongs to a specific class is impossible. These compounds are often classified into specific groups of substances: carbohydrates, proteins, nucleic acids, antibiotics, alkaloids, etc.

To name organic compounds, two nomenclatures are used: rational and systematic (IUPAC) and trivial names.

Compilation of names according to IUPAC nomenclature

1) The name of the compound is based on 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 (ultimate, no multiple connections);
-ene (in the presence of a double bond);
-in (in the presence of a triple bond).

If there are several multiple bonds, then the suffix indicates the number of such bonds (-diene, -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=CH2
butadiene-1,3

Groups such as nitro-, halogens, hydrocarbon radicals that are not included in the main chain are placed in the prefix. They are listed in alphabetical order. The position of the substituent is indicated by the number before the prefix.

The order of naming is as follows:

1. Find the longest chain of C atoms.

2. Number the carbon atoms of the main chain sequentially, starting from the end closest to the branch.

3. The name of the alkane is composed 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)

There are several definitions of what organic substances are and how they differ from another group of compounds - inorganic. One of the most common explanations comes from the name "hydrocarbons". Indeed, at the heart of all organic molecules are chains of carbon atoms bonded to hydrogen. There are also other elements called “organogenic”.

Organic chemistry before the discovery of urea

Since ancient times, people have used many natural substances and minerals: sulfur, gold, iron and copper ore, table salt. Throughout the existence of science - from ancient times to the first half of the 19th century centuries - scientists could not prove the connection between living and inanimate nature at the level of microscopic structure (atoms, molecules). It was believed that organic substances owe their appearance to a mythical life force - vitalism. There was a myth about the possibility of raising a human “homunculus”. To do this, it was necessary to put various waste products into a barrel and wait a certain time for the vital force to arise.

A crushing blow to vitalism was dealt by the work of Weller, who synthesized the organic substance urea from inorganic components. Thus, it was proven that there is no vital force, nature is one, organisms and inorganic compounds are formed by atoms of the same elements. The composition of urea was known before Weller’s work; studying this compound was not difficult in those years. The very fact of obtaining a substance characteristic of metabolism outside the body of an animal or human was remarkable.

Theory of A. M. Butlerov

The role of the Russian school of chemists in the development of science studying organic substances is great. Entire eras in the development of organic synthesis are associated with the names of Butlerov, Markovnikov, Zelinsky, and Lebedev. The founder of the theory of the structure of compounds is A. M. Butlerov. The famous chemist in the 60s of the 19th century explained the composition of organic substances, the reasons for the diversity of their structure, and revealed the relationship that exists between the composition, structure and properties of substances.

Based on Butlerov’s conclusions, it was possible not only to systematize knowledge about already existing organic compounds. It became possible to predict the properties of not yet known to science substances, create technological schemes for their production in industrial conditions. Many ideas of leading organic chemists are being fully realized today.

The oxidation of hydrocarbons produces new organic substances - representatives of other classes (aldehydes, ketones, alcohols, carboxylic acids). For example, large volumes of acetylene are used to produce acetic acid. Part of this reaction product is subsequently consumed to obtain synthetic fibers. An acid solution (9% and 6%) is found in every home - this is ordinary vinegar. The oxidation of organic substances serves as the basis for the production of a very large number of compounds of industrial, agricultural, and medical importance.

Aromatic hydrocarbons

Aromaticity in molecules of organic substances is the presence of one or more benzene nuclei. A chain of 6 carbon atoms closes into a ring, a conjugated bond appears in it, therefore the properties of such hydrocarbons are not similar to other hydrocarbons.

Aromatic hydrocarbons (or arenes) are of great practical importance. Many of them are widely used: benzene, toluene, xylene. They are used as solvents and raw materials for the production of drugs, dyes, rubber, rubber and other products of organic synthesis.

Oxygen-containing compounds

A large group of organic substances contains oxygen atoms. They are part of the most active part of the molecule, its functional group. Alcohols contain one or more hydroxyl species -OH. Examples of alcohols: methanol, ethanol, glycerin. Carboxylic acids contain another functional particle - carboxyl (-COOOH).

Other oxygen-containing organic compounds are aldehydes and ketones. Carboxylic acids, alcohols and aldehydes in large quantities present in various plant organs. They can be sources for obtaining natural products (acetic acid, ethyl alcohol, menthol).

Fats are compounds of carboxylic acids and the trihydric alcohol glycerol. In addition to alcohols and linear acids, there are organic compounds with a benzene ring and a functional group. Examples of aromatic alcohols: phenol, toluene.

Carbohydrates

The most important organic substances of the body that make up cells are proteins, enzymes, nucleic acids, carbohydrates and fats (lipids). Simple carbohydrates - monosaccharides - are found in cells in the form of ribose, deoxyribose, fructose and glucose. The last carbohydrate on this short list is the main metabolic substance in cells. Ribose and deoxyribose are components of ribonucleic and deoxyribonucleic acids (RNA and DNA).

When glucose molecules are broken down, energy is released that is necessary for life. First, it is stored during the formation of a kind of energy carrier - adenosine triphosphoric acid (ATP). This substance is transported in the blood and delivered to tissues and cells. With the sequential elimination of three phosphoric acid residues from adenosine, energy is released.

Fats

Lipids are substances of living organisms that have specific properties. They do not dissolve in water and are hydrophobic particles. The seeds and fruits of some plants, nervous tissue, liver, kidneys, and the blood of animals and humans are especially rich in substances of this class.

The skin of humans and animals contains many small sebaceous glands. The secretion they secrete is brought to the surface of the body, lubricates it, protects it from moisture loss and the penetration of microbes. A layer of subcutaneous fat protects against damage internal organs, serves as a reserve substance.

Squirrels

Proteins make up more than half of all organic substances in the cell; in some tissues their content reaches 80%. All types of proteins are characterized by high molecular weights and the presence of primary, secondary, tertiary and quaternary structures. When heated, they are destroyed - denaturation occurs. The primary structure is a huge chain of amino acids for the microcosm. Under the action of special enzymes in the digestive system of animals and humans, the protein macromolecule will break down into its component parts. They enter cells where the synthesis of organic substances occurs - other proteins specific to each living creature.

Enzymes and their role

Reactions in the cell proceed at a speed that is difficult to achieve under industrial conditions, thanks to catalysts - enzymes. There are enzymes that act only on proteins - lipases. Starch hydrolysis occurs with the participation of amylase. Lipases are needed to break down fats into their constituent parts. Processes involving enzymes occur in all living organisms. If a person does not have any enzyme in his cells, this affects his metabolism and overall health.

Nucleic acids

Substances, first discovered and isolated from cell nuclei, perform the function of transmitting hereditary characteristics. The main amount of DNA is contained in chromosomes, and RNA molecules are located in the cytoplasm. When DNA is reduplicated (doubling), it becomes possible to transfer hereditary information to germ cells - gametes. When they merge, the new organism receives genetic material from its parents.

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

Story

The term “organic substances” itself appeared in the everyday life of scientists at the stage early development chemistry. At that time, vitalistic worldviews dominated. This was a continuation of the traditions of Aristotle and Pliny. During this period, pundits were busy dividing the world into living and nonliving. Moreover, all substances without exception were clearly divided into mineral and organic. It was believed that a special “force” was needed to synthesize compounds of “living” substances. It is inherent in all living beings, and without it organic elements cannot be formed.

This is funny for modern science the statement prevailed for a very long time, until in 1828 Friedrich Wöhler experimentally 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 forms the basis of 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 interesting element. Carbon is capable of forming chains from its atoms. It is very important that the connection between them is stable.

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

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

Compound

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 remaining 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 certainly leads to the appearance of isomers. First of all, they are formed when carbon molecules combine. Isomers are different substances that have one 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 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 classes of organic substances are there?

Organic compounds include several classes. Everyone knows them. lipids and carbohydrates. These groups can be called biological polymers. They are involved in metabolism 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 consist 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 components 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 of an organic substance of this class contains amine (-NH 2) and carboxyl (-COOH) components. They are connected to each other by the same carbon bonds.

Functions of proteins

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

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

Some transport various substances in the body, such as oxygen. Organic matter is also capable of attaching to them. This is how it works transport function. Proteins carry metal ions, fatty acids, hormones and, of course, carbon dioxide and hemoglobin. Transport also occurs at the intercellular level.

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

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

The oxidation of organic substances releases large amounts of energy. But, as a rule, proteins are spent on energy needs very rarely. This occurs when all reserves are exhausted. Lipids and carbohydrates are best suited for this. Therefore, proteins can perform an energy function, but only under certain conditions.

Lipids

An organic substance is also a fat-like compound. Lipids belong to the simplest biological molecules. They are insoluble in water, but disintegrate 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 them are fats. In the body of animals and plants, these substances perform many important functions. Many lipids are used in medicine and industry.

Functions of lipids

These are organic chemical substances together with proteins in cells they 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. Significant amounts of energy reserves can be stored in the body in the form of lipids. Sometimes there are even more of them than are needed for normal life activities. With pathological changes in metabolism, there are more “fat” cells. 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 soil during the cold season. In reality, they use up the reserves of oils and fats that they made over the summer.

In the human and animal body, fats can also perform 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, blows.

In addition, fats have a low level of thermal conductivity, which helps 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 water-repellent and lubricating functions. The wax coats their feathers and makes them more flexible. Some types of plants have the same coating on the leaves.

Carbohydrates

The formula of an organic substance C n (H 2 O) m indicates that the compound belongs to the class of carbohydrates. The name of these molecules refers to the fact that they contain oxygen and hydrogen in the same amount as water. In addition to these chemical elements, 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 initial products of the synthesis in plants of other substances, for example, alcohols, organic acids and amino acids. Carbohydrates are also found in animal and fungal cells. They are also found among the main components of bacteria and protozoa. Thus, in an animal cell there are from 1 to 2% of them, and in a plant cell their amount can reach 90%.

Today there are only three groups of carbohydrates:

Simple sugars (monosaccharides);

Oligosaccharides, consisting of several molecules of simple sugars connected in series;

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

Functions of carbohydrates

All organic substances in a cell perform specific functions. For example, glucose is the main energy source. It is broken down in cells all occurring during cellular respiration. Glycogen and starch constitute the main energy reserves, the former in animals and the latter in plants.

Carbohydrates also perform a structural function. Cellulose is the main component of plant cell walls. 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, they are part of the cytoplasmic membrane - in the form of glycolipids and glycoproteins. Glycocalyx is also often detected in cells. In synthesis nucleic acids pentoses are involved. When is included in DNA, and ribose is included in RNA. These components are also found in coenzymes, for example, 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 clotting. It is formed during tissue damage and blocks the formation of blood clots in blood 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 substances. Chemistry also includes nucleic acids. These are phosphorus-containing biopolymers. They, located in the cell nucleus and cytoplasm of all living beings, ensure the transmission and storage of genetic data. These substances were discovered thanks to the biochemist F. Miescher, who studied salmon sperm. This was an "accidental" discovery. A little later, RNA and DNA were discovered in all plant and animal organisms. Nucleic acids were also isolated 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 ribose is found in the RNA molecule.

Researches nucleic acids organic chemistry. Topics for research are also dictated by medicine. DNA codes hide many genetic diseases that scientists have yet to discover.