Variety of organic and inorganic substances. organic matter

1A. Organisms that form organic substances from inorganic:

1.heterotrophs

2. autotrophs

2A. During the dark phase of photosynthesis:

1.formation of ATP

2. formation of NADP H

3.oxygen release

4.formation of carbohydrates

3A. During photosynthesis, the formation of oxygen is released during the decomposition of molecules:

1.carbon dioxide

2.glucose

4.Carbon dioxide and water

4A. Photosynthesis converts light energy into:

1.Electric energy

2.chemical energy of organic compounds

3.thermal energy

4.Chemical energy of inorganic compounds

5A. Photolysis of water in living organisms proceeds in the process:

1.breath

2.photosynthesis

3.fermentation

4.Chemosynthesis

6A. The end products of the oxidation of organic substances in the cell are:

1.ADP and water

2.ammonia and carbon dioxide

3.water and carbon dioxide

1.proteins to amino acids

2.Starch to glucose

3.DNA to nucleotides

8A. Provide glycolysis enzymes:

2. cytoplasm

3.mitochondria

4.plastid

9A. During glycolysis, a mole of glucose is stored in the form of ATP:

10A. Three moles of glucose underwent complete oxidation in the animal cell, and carbon dioxide was released:

11A. In the process of chemosynthesis, organisms convert the energy of chemical bonds:

1.lipids

2.polysaccharides

4.Inorganic substances

12A. Each protein molecule in DNA corresponds to:

1.triplet

4.nucleotide

13A. The genetic code is common to all living organisms, this property:

1.continuity

2. redundancy

3.versatility

4.specificity

14A. In the genetic code, one triplet corresponds to only one amino acid, this is how it manifests itself:

1.continuity

2. redundancy

3.versatility

4.specificity

15A. If the nucleotide composition of DNA is ATT-GCH-TAT, then the nucleotide composition of i-RNA:
1.TAA-CHTs-UTA

2.TAA-GCG-UTU

3.UAA-CHC-AUA

4.UAA-CHC-ATA

1.tuberculosis causative agent

2. fly agaric

4.bacteriophage

17A. Antibiotic:

1.inhibits protein synthesis of the pathogen

4.is a protective blood protein

18A. The section of the DNA molecule from which transcription occurs has 30,000 nucleotides (both strands). For transcription you will need:

1.always one

2.always two

3.always three

20A. The region of the mRNA from which translation occurs contains 153 nucleotides; in this region, a polypeptide is encoded from:

1.153 amino acids

2.51 amino acids

3.49 amino acids

4.459 amino acids

B1. Establish a correspondence between the characteristic and the type of metabolism in the cell:

B. DNA molecules double

1)plastic exchange

2) energy metabolism

IN 2. Establish a correspondence between the characteristic and the phase of the photosynthesis process:

B. ATP energy is used

D. photolysis of water occurs

1) light

2) dark

IN 3. The oxygen stage of energy metabolism is characterized by:

A. synthesis of energy in the form of ATP

B. breakdown of glucose

G. splitting fat molecules

D. the formation of carbon dioxide

E. implementation in the cytoplasm

AT 4. Build the sequence of reactions of protein biosynthesis by writing the numbers in the required order:

1) removal of information from DNA

4) entry of i-RNA to ribosomes

OPTION 2

1A. Organisms that form organic substances only from organic:

1.heterotrophs

2. autotrophs

3.chemotrophs

4. mixotrophs

2A. During the light phase of photosynthesis:

1.formation of ATP

2.formation of glucose

3.carbon dioxide release

4.formation of carbohydrates

3A. During photosynthesis, oxygen is produced during the process:

1.Protein biosynthesis

2.photolysis

3.excitation of the chlorophyll molecule

4.Compound carbon dioxide and water

4A. As a result of photosynthesis, light energy is converted into:

1. thermal energy

2.Chemical energy of inorganic compounds

3. electrical energy thermal energy

4.chemical energy of organic compounds

5A. Respiration in anaerobes in living organisms proceeds in the process:

1.oxygen oxidation

2.photosynthesis

3.fermentation

4.Chemosynthesis

6A. The end products of carbohydrate oxidation in the cell are:

1.ADP and water

2.ammonia and carbon dioxide

3.water and carbon dioxide

4.ammonia, carbon dioxide and water

7A. At the preparatory stage of the breakdown of carbohydrates, hydrolysis occurs:

1. cellulose to glucose

2. proteins to amino acids

3.DNA to nucleotides

4.fats to glycerol and carboxylic acids

8A. Enzymes provide oxygen oxidation:

1.Digestive tract and lysosomes

2. cytoplasm

3.mitochondria

4.plastid

9A. During glycolysis, 3 mol of glucose is stored in the form of ATP:

10A. Two moles of glucose underwent complete oxidation in an animal cell, and carbon dioxide was released:

11A. In the process of chemosynthesis, organisms convert the energy of oxidation:

1.sulfur compounds

2.organic compounds

3.starch

12A. One gene corresponds to information about the molecule:

1.amino acids

2.starch

4.nucleotide

13A. The genetic code consists of three nucleotides, which means it:

1. specific

2. redundant

3.universal

4.triplet

14A. In the genetic code, one amino acid corresponds to 2-6 triplets, which manifests itself in this:

1.continuity

2. redundancy

3.versatility

4.specificity

15A. If the nucleotide composition of DNA is ATT-CHC-TAT, then the nucleotide composition of i-RNA is:
1.TAA-CHTs-UTA

2.UAA-GCG-AUA

3.UAA-CHC-AUA

4.UAA-CHC-ATA

16A. Protein synthesis does not occur on its own ribosomes in:

1.tobacco mosaic virus

2. Drosophila

3.ant

4.Vibrio cholerae

17A. Antibiotic:

1. is a protective blood protein

2.synthesizes a new protein in the body

3.is a weakened pathogen

4.inhibits protein synthesis of the pathogen

18A. The section of the DNA molecule where replication occurs has 30,000 nucleotides (both strands). For replication you will need:

19A. How many different amino acids can one tRNA transport:

1.always one

2.always two

3.always three

4. Some may carry one, some may carry several.

20A. The DNA region from which transcription occurs contains 153 nucleotides; this region encodes a polypeptide from:

1.153 amino acids

2.51 amino acids

3.49 amino acids

4.459 amino acids

IN 1. Establish a correspondence between the characteristic and the phase of the photosynthesis process:

A. carbon dioxide molecule forms glucose

B. ATP energy is used

B. the chlorophyll molecule is excited

D. photolysis of water occurs

D. ATP is formed from ADP molecules

1) light

2) dark

IN 2. Build the sequence of reactions of protein biosynthesis by writing the numbers in the required order:

1) transcription on DNA

2) t-RNA anticodon recognition of its codon on i-RNA

3) amino acid cleavage from t-RNA

4) connection of i-RNA with a ribosome

5) attachment of an amino acid to a protein chain.

IN 3. The anoxic stage of energy metabolism is characterized by:

A. synthesis of energy in the form of ATP

B. implementation in mitochondria

B. breakdown of glucose

G. splitting fat molecules

D.PVC formation

E. implementation in the cytoplasm

B4. Establish a correspondence between the characteristic and the type of metabolism in the cell:

A. protein biosynthesis is carried out

B. photosynthesis in plant cells

B. DNA molecules double

D. fats are broken down into glycerol and fatty acids

E. The end products of metabolism are carbon dioxide and water.

1)plastic exchange

2) energy metabolism

ANSWERS: 1 OPTION

C3 - A, B, D

B4 - 1,4,2,5,3

ANSWERS: 2 OPTION

B2 - 1,4,2,5,3

A living cell of any organism consists of 25–30% organic components.

Organic components include both polymers and relatively small molecules - pigments, hormones, ATP, etc.

The cells of living organisms differ from each other in structure, functions and in their biochemical composition. However, each group of organic substances has a similar definition in a biology course and performs the same functions in any type of cell. The main constituents are fats, proteins, carbohydrates and nucleic acids.

Lipids

Lipids are called fats and fat-like substances. This biochemical group is distinguished by good solubility in organic substances, but it is insoluble in water.

Fats can be solid or liquid. The first is more typical for animal fats, the second - for vegetable fats.

The functions of fats are as follows:

Carbohydrates

Carbohydrates are organic monomeric and polymeric substances that contain carbon, hydrogen and oxygen in their composition. When they are broken down, the cell receives a significant amount of energy.

According to the chemical composition, the following classes of carbohydrates are distinguished:

Compared to animal cells, vegetable contain in their composition a greater amount of carbohydrates. This is due to the ability of plant cells to reproduce carbohydrates during photosynthesis.

The main functions of carbohydrates in a living cell are energy and structural.

energy function carbohydrates is reduced to the accumulation of energy reserves and their release as needed. Plant cells accumulate starch during the growing season, which is deposited in tubers and bulbs. In animal organisms, this role is played by the polysaccharide glycogen, which is synthesized and accumulated in the liver.

structural function carbohydrates are made in plant cells. Almost the entire cell wall of plants is made up of the polysaccharide cellulose.

Squirrels

Proteins are organic polymeric substances, which occupy a leading place both in quantity in a living cell and in their significance in biology. The entire dry mass of an animal cell consists of approximately half of the protein. This class of organic compounds is remarkably diverse. Only in the human body there are about 5 million different proteins. They not only differ from each other, but also have differences with the proteins of other organisms. And all this colossal variety of protein molecules is built from only 20 varieties of amino acids.

If a protein is exposed to thermal or chemical factors, hydrogen and bisulfide bonds are destroyed in the molecules. This leads to protein denaturation and changes in the structure and function of the cell membrane.

All proteins can be conditionally divided into two classes: globular (these include enzymes, hormones and antibodies), and fibrillar - collagen, elastin, keratin.

Functions of a protein in a living cell:

Nucleic acids

Nucleic acids are essential for the structure and proper functioning of cells. The chemical structure of these substances is such that it allows you to save and inherit information about the protein structure of cells. This information is transmitted to daughter cells and at each stage of their development a certain type of protein is formed.

Since the vast majority of the structural and functional features of a cell are due to their protein component, the stability that distinguishes nucleic acids is very important. In turn, the development and condition of the organism as a whole depends on the stability of the structure and functions of individual cells.

There are two types of nucleic acids - ribonucleic (RNA) and deoxyribonucleic (DNA).

DNA is polymer molecule, which consists of a pair of helices of nucleotides. Each monomer of the DNA molecule is represented as a nucleotide. Nucleotides are composed of nitrogenous bases (adenine, cytosine, thymine, guanine), a carbohydrate (deoxyribose) and a phosphoric acid residue.

All nitrogenous bases are connected to each other in a strictly defined way. Adenine is always located against thymine, and guanine is always located against cytosine. This selective connection is called complementarity and plays a very important role in the formation of protein structure.

All adjacent nucleotides are linked to each other by a phosphoric acid residue and deoxyribose.

Ribonucleic acid has a strong resemblance to deoxyribonucleic acid. The difference lies in the fact that instead of thymine, the nitrogenous base uracil is present in the structure of the molecule. Instead of deoxyribose, this compound contains the carbohydrate ribose.

All nucleotides in the RNA chain are connected through a phosphorus residue and ribose.

By its structure RNA can be single or double stranded. In a number of viruses, double-stranded RNAs perform the functions of chromosomes - they are carriers of genetic information. With the help of single-stranded RNA, information about the composition of the protein molecule is transferred.

“Here, as elsewhere, distinctions and rubrics do not belong to nature,
not essence, but human judgment which
they are for your own convenience."
A. M. Butlerov.

First time term "organic chemistry" appeared in 1808 in the "textbook of chemistry" by the Swedish scientist AND I. Berzelius. The name "organic compounds" appeared a little earlier. Scientists of that era divided substances into two groups rather conditionally: they believed that living beings consist of special organic sconnections, and objects of inanimate nature - from inorganic.

For many simple substances, their allotropic forms of existence are known: carbon - in the form of graphite and diamond, etc. Currently, about 400 allotropic modifications of simple substances are known.

The variety of complex substances is due to their different qualitative and quantitative composition. For example, five forms of oxides are known for nitrogen: N 2 O, NO, N 2 O 3 , NO 2 , N 2 O 5 ; for hydrogen, two forms: H 2 O and H 2 O 2.

There are no fundamental differences between organic and inorganic substances. They differ only in some features.

Most inorganic substances have a non-molecular structure, so they have high melting and boiling points. Inorganic substances do not contain carbon. Inorganic substances include: metals (Ca, K, Na, etc.), non-metals, noble gases (He, Ne, Ar, Kr, Xe, etc.), amphoteric simple substances (Fe, Al, Mn, etc.), oxides (various compounds with oxygen), hydroxides, salts and binary compounds.

Water is an inorganic substance. It is a universal solvent and has high heat capacity and thermal conductivity. Water is a source of oxygen and hydrogen; the main environment for the flow of biochemical and chemical reactions.

Organic substances, as a rule, have a molecular structure, have low melting points, and easily decompose when heated. The molecules of all organic substances contain carbon (with the exception of carbides, carbonates, carbon oxides, carbon-containing gases and cyanides). Chemical bonds in the molecules of organic compounds are predominantly covalent.

The unique property of carbon to form chains of atoms makes it possible to form a huge number of unique compounds.

Most major classes of organic substances are of biological origin. These include proteins, carbohydrates, nucleic acids, lipids. These compounds, in addition to carbon, contain hydrogen, nitrogen, oxygen, sulfur and phosphorus.

Carbon compounds are common in nature. They are part of the flora and fauna, which means they provide clothes, shoes, fuel, medicines, food, dyes, etc.
Everyday experience shows that almost all organic substances, such as vegetable oils, animal fats, fabrics, wood, paper, natural gases, do not withstand elevated temperatures and decompose or burn relatively easily, while most inorganic substances do. Thus, organic substances are less durable than inorganic ones.
Synthesis of organic from inorganic substances.
In 1828 a German chemist F. Wöhler managed to artificially obtain urea. The starting material in this case was an inorganic salt - potassium cyanide (KCN), the oxidation of which produces potassium cyanate (KOCN). The exchange decomposition of potassium cyanate with ammonium sulfate produces ammonium cyanate, which, when heated, turns into urea:

In 1842 a Russian scientist N. N. Zinin synthesized aniline, which was previously obtained only from a natural dye. In 1854 a French scientist M.Bertlot got fat-like substance, and in 1861 an outstanding Russian chemist A. M. Butlerov - sugary substance.

The composition of a living cell includes the same chemical elements that are part of inanimate nature. Of the 104 elements of the periodic system of D. I. Mendeleev, 60 were found in cells.

They are divided into three groups:

1. the main elements are oxygen, carbon, hydrogen and nitrogen (98% of the cell composition);
2. elements that make up tenths and hundredths of a percent - potassium, phosphorus, sulfur, magnesium, iron, chlorine, calcium, sodium (1.9% in total);
3. all other elements present in even smaller amounts are trace elements.

The molecular composition of the cell is complex and heterogeneous. Separate compounds - water and mineral salts - are also found in inanimate nature; others - organic compounds: carbohydrates, fats, proteins, nucleic acids, etc. - are characteristic only of living organisms.

INORGANIC SUBSTANCES

Water makes up about 80% of the mass of the cell; in young fast-growing cells - up to 95%, in old ones - 60%.

The role of water in the cell is great.

It is the main medium and solvent, participates in most chemical reactions, the movement of substances, thermoregulation, the formation of cellular structures, determines the volume and elasticity of the cell. Most substances enter the body and are excreted from it in an aqueous solution. The biological role of water is determined by the specificity of the structure: the polarity of its molecules and the ability to form hydrogen bonds, due to which complexes of several water molecules arise. If the attraction energy between water molecules is less than between water molecules and a substance, it dissolves in water. Such substances are called hydrophilic (from the Greek "hydro" - water, "fillet" - I love). These are many mineral salts, proteins, carbohydrates, etc. If the energy of attraction between water molecules is greater than the energy of attraction between molecules of water and a substance, such substances are insoluble (or slightly soluble), they are called hydrophobic (from the Greek "phobos" - fear) - fats, lipids, etc.

Mineral salts in aqueous solutions of the cell dissociate into cations and anions, providing a stable amount of the necessary chemical elements and osmotic pressure. Of the cations, the most important are K + , Na + , Ca 2+ , Mg + . The concentration of individual cations in the cell and in the extracellular environment is not the same. In a living cell, the concentration of K is high, Na + is low, and in blood plasma, on the contrary, there is a high concentration of Na + and low K +. This is due to the selective permeability of membranes. The difference in the concentration of ions in the cell and the environment ensures the flow of water from the environment into the cell and the absorption of water by the roots of plants. The lack of individual elements - Fe, P, Mg, Co, Zn - blocks the formation of nucleic acids, hemoglobin, proteins and other vital substances and leads to serious diseases. Anions determine the constancy of the pH-cell environment (neutral and slightly alkaline). Of the anions, the most important are HPO 4 2-, H 2 PO 4 -, Cl -, HCO 3 -

ORGANIC SUBSTANCES

Organic substances in the complex form about 20-30% of the cell composition.

Carbohydrates- organic compounds consisting of carbon, hydrogen and oxygen. They are divided into simple - monosaccharides (from the Greek "monos" - one) and complex - polysaccharides (from the Greek "poly" - a lot).

Monosaccharides(their general formula is C n H 2n O n) - colorless substances with a pleasant sweet taste, highly soluble in water. They differ in the number of carbon atoms. Of the monosaccharides, hexoses (with 6 C atoms) are the most common: glucose, fructose (found in fruits, honey, blood) and galactose (found in milk). Of the pentoses (with 5 C atoms), the most common are ribose and deoxyribose, which are part of nucleic acids and ATP.

Polysaccharides refers to polymers - compounds in which the same monomer is repeated many times. The monomers of polysaccharides are monosaccharides. Polysaccharides are water soluble and many have a sweet taste. Of these, the most simple disaccharides, consisting of two monosaccharides. For example, sucrose is made up of glucose and fructose; milk sugar - from glucose and galactose. With an increase in the number of monomers, the solubility of polysaccharides decreases. Of the high molecular weight polysaccharides, glycogen is the most common in animals, and starch and fiber (cellulose) in plants. The latter consists of 150-200 glucose molecules.

Carbohydrates- the main source of energy for all forms of cellular activity (movement, biosynthesis, secretion, etc.). Splitting to the simplest products CO 2 and H 2 O, 1 g of carbohydrate releases 17.6 kJ of energy. Carbohydrates perform a building function in plants (their shells are made of cellulose) and the role of reserve substances (in plants - starch, in animals - glycogen).

Lipids- These are water-insoluble fat-like substances and fats, consisting of glycerol and high molecular weight fatty acids. Animal fats are found in milk, meat, subcutaneous tissue. At room temperature, they are solids. In plants, fats are found in seeds, fruits, and other organs. At room temperature, they are liquids. Fat-like substances are similar to fats in chemical structure. There are many of them in the yolk of eggs, brain cells and other tissues.

The role of lipids is determined by their structural function. They make up cell membranes, which, due to their hydrophobicity, prevent the contents of the cell from mixing with the environment. Lipids perform an energy function. Splitting to CO 2 and H 2 O, 1 g of fat releases 38.9 kJ of energy. They poorly conduct heat, accumulating in the subcutaneous tissue (and other organs and tissues), perform a protective function and the role of reserve substances.

Squirrels- the most specific and important for the body. They belong to non-periodic polymers. Unlike other polymers, their molecules consist of similar but non-identical monomers - 20 different amino acids.

Each amino acid has its own name, special structure and properties. Their general formula can be represented as follows

An amino acid molecule consists of a specific part (radical R) and a part that is the same for all amino acids, including an amino group (-NH 2) with basic properties, and a carboxyl group (COOH) with acidic properties. The presence of acidic and basic groups in one molecule determines their high reactivity. Through these groups, the connection of amino acids occurs in the formation of a polymer - protein. In this case, a water molecule is released from the amino group of one amino acid and the carboxyl of another, and the released electrons are combined to form a peptide bond. Therefore, proteins are called polypeptides.

A protein molecule is a chain of several tens or hundreds of amino acids.

Protein molecules are huge, so they are called macromolecules. Proteins, like amino acids, are highly reactive and are able to react with acids and alkalis. They differ in composition, quantity and sequence of amino acids (the number of such combinations of 20 amino acids is almost infinite). This explains the diversity of proteins.

There are four levels of organization in the structure of protein molecules (59)

• Primary Structure- a polypeptide chain of amino acids linked in a certain sequence by covalent (strong) peptide bonds.
• secondary structure- a polypeptide chain twisted into a tight helix. In it, low-strength hydrogen bonds arise between the peptide bonds of adjacent turns (and other atoms). Together, they provide a fairly strong structure.
• Tertiary structure is a bizarre, but specific configuration for each protein - a globule. It is held together by weak hydrophobic bonds or cohesive forces between non-polar radicals that are found in many amino acids. Due to their multiplicity, they provide sufficient stability of the protein macromolecule and its mobility. The tertiary structure of proteins is also supported by covalent S - S (es - es) bonds that arise between radicals of the sulfur-containing amino acid cysteine, which are distant from each other.
• Quaternary structure not typical for all proteins. It occurs when several protein macromolecules combine to form complexes. For example, human blood hemoglobin is a complex of four macromolecules of this protein.

This complexity of the structure of protein molecules is associated with a variety of functions inherent in these biopolymers. However, the structure of protein molecules depends on the properties of the environment.

Violation of the natural structure of the protein is called denaturation. It can occur under the influence of high temperature, chemicals, radiant energy and other factors. With a weak impact, only the quaternary structure breaks down, with a stronger one, the tertiary one, and then the secondary one, and the protein remains in the form of a primary structure - a polypeptide chain. This process is partially reversible, and the denatured protein is able to restore its structure.

The role of protein in cell life is enormous.

Squirrels is the building material of the body. They are involved in the construction of the shell, organelles and membranes of the cell and individual tissues (hair, blood vessels, etc.). Many proteins act as catalysts in the cell - enzymes that speed up cellular reactions by tens, hundreds of millions of times. About a thousand enzymes are known. In addition to protein, their composition includes metals Mg, Fe, Mn, vitamins, etc.

Each reaction is catalyzed by its own particular enzyme. In this case, not the entire enzyme acts, but a certain area - the active center. It fits to the substrate like a key to a lock. Enzymes act at a certain temperature and pH. Special contractile proteins provide motor functions of cells (movement of flagellates, ciliates, muscle contraction, etc.). Separate proteins (blood hemoglobin) perform a transport function, delivering oxygen to all organs and tissues of the body. Specific proteins - antibodies - perform a protective function, neutralizing foreign substances. Some proteins perform an energy function. Breaking down to amino acids, and then to even simpler substances, 1 g of protein releases 17.6 kJ of energy.

Nucleic acids(from the Latin "nucleus" - the core) were first discovered in the core. They are of two types - deoxyribonucleic acids(DNA) and ribonucleic acids(RNA). Their biological role is great, they determine the synthesis of proteins and the transfer of hereditary information from one generation to another.

The DNA molecule has a complex structure. It consists of two spirally twisted chains. The width of the double helix is ​​2 nm 1 , the length is several tens and even hundreds of micromicrons (hundreds or thousands of times larger than the largest protein molecule). DNA is a polymer whose monomers are nucleotides - compounds consisting of a molecule of phosphoric acid, a carbohydrate - deoxyribose and a nitrogenous base. Their general formula is as follows:

Phosphoric acid and carbohydrate are the same for all nucleotides, and there are four types of nitrogenous bases: adenine, guanine, cytosine, and thymine. They determine the name of the corresponding nucleotides:

• adenyl (A),
• guanyl (G),
• cytosyl (C),
• thymidyl (T).

Each DNA strand is a polynucleotide consisting of several tens of thousands of nucleotides. In it, neighboring nucleotides are connected by a strong covalent bond between phosphoric acid and deoxyribose.

With the enormous size of DNA molecules, the combination of four nucleotides in them can be infinitely large.

During the formation of the DNA double helix, the nitrogenous bases of one strand are arranged in a strictly defined order against the nitrogenous bases of the other. At the same time, T is always against A, and only C is against G. This is explained by the fact that A and T, as well as G and C, strictly correspond to each other, like two halves of broken glass, and are additional or complementary(from the Greek "complement" - addition) to each other. If the sequence of nucleotides in one DNA strand is known, then the nucleotides of another strand can be established by the principle of complementarity (see Appendix, task 1). Complementary nucleotides are joined by hydrogen bonds.

Between A and T there are two bonds, between G and C - three.

The duplication of the DNA molecule is its unique feature, which ensures the transfer of hereditary information from the mother cell to the daughter cells. The process of DNA duplication is called DNA replication. It is carried out as follows. Shortly before cell division, the DNA molecule unwinds and its double strand, under the action of an enzyme, is split from one end into two independent chains. On each half of the free nucleotides of the cell, according to the principle of complementarity, a second chain is built. As a result, instead of one DNA molecule, two completely identical molecules appear.

RNA- a polymer similar in structure to one strand of DNA, but much smaller. RNA monomers are nucleotides consisting of phosphoric acid, a carbohydrate (ribose) and a nitrogenous base. The three nitrogenous bases of RNA - adenine, guanine and cytosine - correspond to those of DNA, and the fourth is different. Instead of thymine, RNA contains uracil. The formation of the RNA polymer occurs through covalent bonds between the ribose and phosphoric acid of neighboring nucleotides. Three types of RNA are known: messenger RNA(i-RNA) transmits information about the structure of the protein from the DNA molecule; transfer RNA(t-RNA) transports amino acids to the site of protein synthesis; ribosomal RNA (rRNA) is found in ribosomes and is involved in protein synthesis.

ATP- adenosine triphosphoric acid is an important organic compound. Structurally, it is a nucleotide. It consists of the nitrogenous base adenine, carbohydrate - ribose and three molecules of phosphoric acid. ATP is an unstable structure, under the influence of the enzyme, the bond between "P" and "O" is broken, a molecule of phosphoric acid is split off and ATP passes into

In the past, scientists divided all substances in nature into conditionally inanimate and living ones, including the animal and plant kingdoms among the latter. Substances of the first group are called mineral. And those that entered the second, began to be called organic substances.

What is meant by this? 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 that 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 among them.

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 at the same time, 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 bond multiplicity increases, the chain of atoms becomes shorter, and the bond stability increases.

And carbon is 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 carefully look at your reflection. Each of us is a walking textbook on 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, which serve as "fuel" and a source of energy. Fats that store energy reserves. Hormones that control organ function and even your behavior. Enzymes that start chemical reactions within you. And even the "source code," the strands of DNA, are all carbon-based organic compounds.

Composition of organic substances

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

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

The structure of organic substances

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

You remember that carbon atoms are able to form very strong bonds with each other, connecting in chains. The result is stable molecules. The way carbon atoms are connected in a chain (arranged in a zigzag pattern) is one of the key features of its structure. Carbon can combine both into open chains and into closed (cyclic) chains.

It is also important that the structure of chemicals directly affects their chemical properties. A significant role is also played by how atoms and groups of atoms in a molecule affect each other.

Due to the peculiarities of the structure, the number of carbon compounds of the same type goes to tens and hundreds. For example, we can consider hydrogen compounds of carbon: methane, ethane, propane, butane, etc.

For example, methane - 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 is different. Then the chemical properties of the compounds are different. As in the case of acetylene C 2 H 2 and benzene C 6 H 6.

Not the last role in this variety 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, hence the difference in chemical and physical properties. For example, the molecular formula C 4 H 10 can be written for 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 located in a different order (branched and unbranched structure).

Concerning homology- this is a characteristic of such a carbon chain in which each next 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, methane homologues are described by the formula C n H 2n+2 .

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

What classes of organic substances exist?

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.

The hydrocarbons are:

• acyclic compounds:
  • saturated hydrocarbons (alkanes);
  • unsaturated hydrocarbons:
    • alkenes;
    • alkynes;
    • alkadienes.
• cyclic compounds:
  • 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 classes

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 weight of an animal cell is protein). In plants (about 80% of the dry mass of the cell) - for carbohydrates, primarily complex - polysaccharides. Including for 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 the supply of substances. Plants use starch for this purpose, and 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 DNA) and hexoses (glucose, which is well known to you).

Like bricks, at a large construction site of nature, polysaccharides are built from thousands and thousands of monosaccharides. Without them, more precisely, without cellulose, starch, there would be no plants. Yes, and animals without glycogen, lactose and chitin would have a hard time.

Let's look carefully at squirrels. Nature is the greatest master of mosaics and puzzles: from just 20 amino acids, 5 million types of proteins are formed in the human body. Proteins also have many vital functions. For example, construction, regulation of processes in the body, blood coagulation (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 a discord occurs in the fine tuning of the body, antibodies, instead of destroying external enemies, can act as aggressors to their own organs and tissues of the body.

Proteins are also divided into simple (proteins) and complex (proteins). 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.).

Let's 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. These 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 ready to study late or prefer to get up early and do your homework before school, not only your daily routine, but also some adrenal hormones decide.

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 join in chains, react and create thousands of such diverse chemical compounds.

You now have a short guide to organic chemistry. Of course, not all possible information is presented here. Some points you may have to clarify on your own. But you can always use the route we have planned 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 in the article to prepare for chemistry classes at school.

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