Organic matter is a chemical compound containing carbon. The only exceptions are carbonic acid, carbides, carbonates, cyanides and oxides of carbon.
History
The term "organic substances" itself appeared in the everyday life of scientists at the stage of early development of chemistry. At that time, vitalistic worldviews dominated. It was a continuation of the traditions of Aristotle and Pliny. During this period, pundits were busy dividing the world into living and non-living. 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 "strength" was needed. It is inherent in all living beings, and organic elements cannot form without it.
This statement, ridiculous for modern science, dominated 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. It underlies the classification. Almost 27 million organic compounds are known.
Why are there so many organic compounds?
Organic matter is, with a few exceptions, a carbon compound. In fact, this is a very curious element. Carbon is able to form chains from its atoms. It is very important that the connection between them is stable.
In addition, carbon in organic substances exhibits valency - IV. It follows from this that this element is able to form 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. Organic compounds 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 rarer.
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. Existing between atomsdifferent typology of bonds inevitably leads to the appearance of isomers. First of all, they are formed by the combination of carbon molecules. Isomers are different substances that have 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 series of organic compounds, in which the formula of neighboring substances differs from the previous ones by one group CH2. This important property is applied in materials science.
What are the classes of organic substances?
There are several classes of organic compounds. They are known to everyone. These are proteins, 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.
Proteins
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 less popular terms can also be found in the literature - proteinogenic and protein-forming amino acids. The formula of this class of organic matter contains amine (-NH2) 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 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 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 types of proteins carry various substances in the body, such as oxygen. Organic matter is also able to join them. This is how the transport function works. 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 process of coagulation. Thus, they prevent more 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 even in unicellular organisms, similarprocesses. The movement of bacterial flagella is also directly related to the sliding of microtubules, which are of a protein nature.
Oxidation of organic matter releases large amounts of energy. But, as a rule, proteins are consumed for energy needs very rarely. This happens when all stocks are exhausted. Lipids and carbohydrates are best suited for this. Therefore, proteins can perform an energy function, but only under certain conditions.
Lipids
A fat-like compound is also an organic substance. Lipids belong to the simplest biological molecules. They are insoluble in water, but decompose in non-polar solutions such as gasoline, ether, and chloroform. They are part of all living cells. Chemically, lipids are esters of 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 organic chemicals, together with proteins in cells, 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 the cells. In the form of lipids, a significant amount of energy reserves can accumulate in the body. Sometimes they are even more than necessary for the implementation of normal life. With pathological changes in the metabolism of "fat" cells, it becomes more. Althoughin 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 period. In reality, they are using up the reserves of oils and fats they made over the summer.
In the human and animal body, fats can also perform a protective function. They are deposited in the subcutaneous tissue and around organs such as the kidneys and intestines. Thus, they serve as a good protection against mechanical damage, that is, shock.
In addition, fats have a low level of thermal conductivity, which helps to keep warm. 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 elastic. Some plant species have the same coating on the leaves.
Carbohydrates
Organic formula C (H2O)m indicates whether the compound belongs to the class 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 the primary products of the photosynthesis process. They are also the initial products of synthesis in plants of othersubstances such as alcohols, organic acids and amino acids. Carbohydrates are also 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%.
Today, there are only three groups of carbohydrates:
- simple sugars (monosaccharides);
- oligosaccharides, consisting of several molecules of successively connected simple sugars;
- polysaccharides, they contain more than 10 molecules of monosaccharides and their derivatives.
Carbohydrate functions
All organic substances in the cell perform certain functions. So, for example, glucose is the main energy source. It is broken down in the cells of all living organisms. This happens during cellular respiration. Glycogen and starch are the main source of energy, with the former in animals and the latter in plants.
Carbohydrates also perform 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. In this case, deoxyribose is included in the DNA, and ribose is included in the 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 clotting. 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 substances. Chemistry also includes nucleic acids. These are phosphorus-containing biopolymers. They, being 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 spermatozoa. It was an "accidental" discovery. A little later, RNA and DNA were also found in all plant and animal organisms. Nucleic acids have also been 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 (RNA) and deoxyribonucleic (DNA). The difference is clear from the name. DNA contains deoxyribose, a five-carbon sugar. And ribose is found in the RNA molecule.
Organic chemistry deals with the study of nucleic acids. Topics for research are also dictated by medicine. There are many genetic diseases hiding in the DNA codes that scientists have yet to discover.
