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The percentage of carbohydrates in the cell. The main function is energy

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The role of carbohydrates in the cell

1. Cage 3
2. Cell composition 3
3. Carbohydrates 5
4. Functions of carbohydrates 7
5. The role of carbohydrates in the cell 7
Bibliography 10
1. Cage
Modern cellular theory consists of the following generalizations.
A cell is an elementary particle of life. The manifestation of life is possible only at a level not lower than the cellular level.
The cells of all living things have a single structural plan. It includes a cytoplasm with various organelles and a membrane. Proteins and nucleic acids form the functional basis of any cell.
The cell originates only from the cell (R. Virkhov, 1858) as a result of division.
The cells of multicellular organisms differ in structural details, which is caused by the performance of various functions. Cells that have a common origin, structure and perform the same functions in the body form tissue (nervous, muscle, integumentary). Tissues form various organs.
2. Cell composition
Any cell contains more than 60 elements of Mendeleev's periodic table. According to the frequency of occurrence, the elements can be divided into three groups:
Main elements. These are carbon (C), hydrogen (H), nitrogen (N), oxygen (O). Their content in the cell exceeds 97%. They are part of all organic substances (proteins, fats, carbohydrates, nucleic acids) and form their basis.
Macronutrients. These include iron (Fe), sulfur (S), calcium (Ca), potassium (K), sodium (Na), phosphorus (P), chlorine (Cl). Macronutrients account for about 2%. They are found in many organic and inorganic substances.
Microelements. They have the greatest variety (there are more than 50 of them), but in the cage, even taken all together, they do not exceed 1%. Trace elements in extremely small quantities are part of many enzymes, hormones or specific tissues, but determine their properties. So, fluoride (F), is part of the tooth enamel, strengthening it.
Iodine (I) is involved in the structure of the thyroid hormone thyroxine, magnesium (Mg) is a part of plant cell chlorophyll, copper (Cu) and selenium (Se) are found in enzymes that protect cells from mutations, zinc (Zn) is associated with memory processes.
All elements of the cell are part of various molecules, form substances that are divided into two classes: inorganic and organic.
Organic substances of the cell are represented by various biochemical polymers, that is, molecules that consist of numerous repetitions of simpler, structurally similar sites (monomers). The organic components of the cell are carbohydrates, fats and fat-like substances, proteins and amino acids, nucleic acids and nucleic bases.
Carbohydrates include organic substances with the general chemical formula C n (H 2 O) n. By structure, carbohydrates are divided into monosaccharides, oligosaccharides and polysaccharides. Monosugars are molecules in the form of one ring, usually containing five or six carbon atoms. Five-carbon sugars - ribose, deoxyribose. Six-carbon sugars - glucose, fructose, galactose. Oligosaccharides are the result of combining a small number of monosaccharides (disacchars, trisachars, etc.) the most common are, for example, cane (beet) sugar - sucrose, consisting of two molecules of glucose and fructose; malt sugar - maltose, formed by two glucose molecules; milk sugar - lactose, formed by a molecule of galactose and a molecule of glucose.
Polysaccharides - starch, glycogen, cellulose, consist of a huge amount of monosaccharides, linked together in more or less branched chains.
3. Carbohydrates
Carbohydrates are organic substances with the general formula Cn (H2O) m.
In the animal cell, carbohydrates are found in quantities not exceeding 5%. Plant cells are richest in carbohydrates, where their content reaches up to 90% of dry mass (potatoes, seeds, etc.)
Carbohydrates are divided into simple (monosaccharides and disaccharides) and complex (polysaccharides).
Monosaccharides are substances such as glucose, pentose, fructose, ribose. disaccharides - sugar, sucrose (consists of glucose and fructose.

Polysaccharides - Formed by many monosaccharides. Monomers of such polysaccharides as starch, glycogen, cellulose are glucose.
Carbohydrates play the role of the main source of energy in the cell. in the process of oxidation of 1 g of carbohydrates, 17.6 kJ are released. Starch in plants and glycogen in animals, deposited in cells, serve as an energy reserve.
Carbohydrates are organic compounds containing hydrogen (H), carbon (C) and oxygen (O), and the number of hydrogen atoms in most cases is twice the number of oxygen atoms. General carbohydrate formula: Cn (H2O) n, where n is at least three. Carbohydrates are formed from water (H2O) and carbon dioxide (CO2) in the process of photosynthesis that occurs in the chloroplasts of green plants (in bacteria, in the process of bacterial photosynthesis or chemosynthesis). Usually, the cell of animal organisms contains about 1% of carbohydrates (in liver cells up to 5%), and in plant cells up to 90% (in potato tubers).
All carbohydrates are divided into 3 groups:
Monosaccharides often contain five (pentoses) or six (hexoses) carbon atoms, the same amount of oxygen and twice as much hydrogen (for example, glucose - C6H12O6). Pentoses (ribose and deoxyribose) are part of nucleic acids and ATP. Hexoses (fructose and glucose) are constantly present in the cells of plant fruits, giving them a sweet taste. Glucose is found in the blood and serves as an energy source for animal cells and tissues;
Disaccharides combine two monosaccharides in one molecule. Food sugar (sucrose) is made up of glucose and fructose molecules, milk sugar (lactose) includes glucose and galactose.
All mono- and disaccharides are highly soluble in water and have a sweet taste.
Polysaccharides (starch, fiber, glycogen, chitin) are formed by tens and hundreds of monomeric units, which are glucose molecules. Polysaccharides are practically insoluble in water and have no sweet taste. The main polysaccharides - starch (in plant cells) and glycogen (in animal cells) are deposited in the form of inclusions and serve as reserve energy substances.
4. Functions of carbohydrates
Carbohydrates have two main functions: energy and construction. For example, cellulose forms the walls of plant cells (cellulose), chitin is the main structural component of the external skeleton of arthropods.
Carbohydrates perform the following functions:
- they are a source of energy (when 1 g of glucose breaks down, 17.6 kJ of energy is released);
- perform a building (structural) function (cellulose membrane in plant cells, chitin in the skeleton of insects and in the cell wall of fungi);
- store nutrients (starch in plant cells, glycogen in animals);
- are constituents of DNA, RNA and ATP.
5. The role of carbohydrates in the cell
Energy. Mono - and oligosaccharides are an important source of energy for any cell. By splitting, they release energy, which is stored in the form of ATP molecules, which are used in many vital processes of the cell and the whole organism. The end products of the breakdown of all carbohydrates are carbon dioxide and water.
Reserve. Due to their solubility, mono- and oligosaccharides are quickly absorbed by the cell, easily migrate through the body, and therefore are unsuitable for long-term storage. The role of energy storage is played by huge water-insoluble polysaccharide molecules. In plants, for example, it is starch, and in animals and fungi it is glycogen. To use these reserves, the body must first convert the polysaccharide into a monosugar.
Construction. The overwhelming majority of plant cells have dense cellulose walls, which provide plants with strength, elasticity and protection from large moisture loss.
Structural. Monosugar can combine with fats, proteins and other substances. For example, ribose is part of all RNA molecules, and deoxyribose is part of DNA.
Sources of carbohydrates in the diet are mainly plant products - bread, cereals, potatoes, vegetables, fruits, berries. From animal products, carbohydrates are found in milk (milk sugar). Foods contain a variety of carbohydrates. Cereals, potatoes contain starch - a complex substance (complex carbohydrate), insoluble in water, but broken down by the action of digestive juices into simpler sugars. In fruits, berries and some vegetables carbohydrates are contained in the form of various simpler sugars - fruit sugar, beet sugar, cane sugar, grape sugar (glucose), etc. These substances are soluble in water and are well absorbed in the body. Water-soluble sugars are rapidly absorbed into the bloodstream. It is advisable to introduce not all carbohydrates in the form of sugars, but to introduce the bulk of them in the form of starch, which is rich in, for example, potatoes. This promotes the gradual delivery of sugar to the tissues. It is recommended to introduce only 20-25% of the total amount of carbohydrates contained in the daily diet directly in the form of sugar. This number also includes the sugar found in sweets, confectionery, fruits and berries.
If carbohydrates are supplied with food in sufficient quantities, they are deposited mainly in the liver and muscles in the form of a special animal starch - glycogen. In the future, the glycogen reserve is broken down in the body to glucose and, entering the blood and other tissues, is used for the needs of the body. With excess nutrition, carbohydrates are converted into fat in the body. Carbohydrates usually include fiber (the membrane of plant cells), which is little used by the human body, but is necessary for proper digestion processes.

Bibliography

1. Chemistry, trans. from English, 2nd ed., M., 1956; Chemistry of carbohydrates, M., 1967

2. Stepanenko B.N., Carbohydrates. Advances in the study of structure and metabolism, M., 1968

4. Alabin V. G., Skrezhko A. D. Nutrition and health. - Minsk, 1994

5. Sotnik Zh.G., Zarichanskaya L.A. Proteins, fats and carbohydrates. - M., Prior, 2000

Glucose is:

one of the most common monosaccharides,
the most important source of energy for all types of work taking place in the cell (this energy is released during the oxidation of glucose during respiration),
monomer of many oligosaccharides and polysaccharides,
an essential component of the blood.

Fructose, or fruit sugar, belongs to the group of hexoses, is sweeter than glucose, in free form it is found in honey (more than 50%) and fruits. It is a monomer of many oligosaccharides and polysaccharides.

Oligosaccharides- carbohydrates formed as a result of a condensation reaction between several (from two to ten) monosaccharide molecules. Depending on the number of monosaccharide residues, disaccharides, trisaccharides, etc. are distinguished. The most common are disaccharides. Properties of oligosaccharides- dissolve in water, crystallize, sweet taste decreases as the number of monosaccharide residues increases. The bond formed between two monosaccharides is called glycosidic.

Sucrose, or cane, or beet sugar, Is a disaccharide consisting of glucose and fructose residues. Contained in plant tissues. It is a food product (common name - sugar). In industry, sucrose is produced from sugar cane (stems contain 10-18%) or sugar beet (root crops contain up to 20% sucrose).

Maltose, or malt sugar, Is a disaccharide consisting of two glucose residues. It is present in germinating seeds of cereals.

Lactose, or milk sugar, Is a disaccharide consisting of glucose and galactose residues. It is present in the milk of all mammals (2-8.5%).

Polysaccharides- these are carbohydrates formed as a result of the polycondensation reaction of many (several tens or more) monosaccharide molecules. Polysaccharide properties- do not dissolve or poorly dissolve in water, do not form clearly shaped crystals, do not have a sweet taste.

Starch(C 6 H 10 O 5) n- a polymer, the monomer of which is α-glucose. Starch polymer chains contain branched (amylopectin, 1,6-glycosidic bonds) and unbranched (amylose, 1,4-glycosidic bonds) sites. Starch is the main reserve carbohydrate of plants, is one of the products of photosynthesis, accumulates in seeds, tubers, rhizomes, and bulbs. The starch content in rice grains is up to 86%, wheat - up to 75%, corn - up to 72%, in potato tubers - up to 25%. Starch is the main carbohydrate human food (digestive enzyme - amylase).

Glycogen(C 6 H 10 O 5) n- a polymer, the monomer of which is also α-glucose. The polymer chains of glycogen resemble the amylopectin regions of starch, but unlike them, they branch even more. Glycogen is the main reserve carbohydrate in animals, in particular humans. It accumulates in the liver (content - up to 20%) and muscles (up to 4%), is a source of glucose.

(C 6 H 10 O 5) n- a polymer, the monomer of which is β-glucose. Polymer chains of cellulose do not branch (β-1,4-glycosidic bonds). The main structural polysaccharide of plant cell walls. The cellulose content in wood is up to 50%, in the fibers of cotton seeds - up to 98%. Cellulose is not broken down by human digestive juices, because it lacks the cellulase enzyme that breaks bonds between β-glucose.

Inulin- a polymer, the monomer of which is fructose. Reserve carbohydrate of plants of the Asteraceae family.

Glycolipids- complex substances formed as a result of the combination of carbohydrates and lipids.

Glycoproteins- complex substances formed as a result of the combination of carbohydrates and proteins.

Functions of carbohydrates

Structure and function of lipids

Lipids do not have a single chemical characteristic. In most benefits, giving determination of lipids, they say that this is a collection group of water-insoluble organic compounds that can be removed from the cell with organic solvents - ether, chloroform and benzene. Lipids can be roughly divided into simple and complex.

Simple lipids in the majority are represented by esters of higher fatty acids and trihydric alcohol of glycerol - triglycerides. Fatty acid have: 1) the same grouping for all acids - a carboxyl group (-COOH) and 2) a radical by which they differ from each other. The radical is a chain of various numbers (from 14 to 22) -CH 2 - groups. Sometimes a fatty acid radical contains one or more double bonds (-CH = CH-), such fatty acid is called unsaturated... If a fatty acid has no double bonds, it is called saturated... When a triglyceride is formed, each of the three hydroxyl groups of glycerol undergoes a condensation reaction with a fatty acid to form three ester bonds.

If triglycerides are dominated by saturated fatty acids, then at 20 ° C they are solid; they are called fats, they are characteristic of animal cells. If triglycerides are dominated by unsaturated fatty acids, then at 20 ° C they are liquid; they are called oils, they are characteristic of plant cells.

1 - triglyceride; 2 - ester link; 3 - unsaturated fatty acid;
4 - hydrophilic head; 5 - hydrophobic tail.

The density of triglycerides is lower than that of water, so they float in water, are on its surface.

Simple lipids also include waxes- esters of higher fatty acids and high molecular weight alcohols (usually with an even number of carbon atoms).

Complex lipids... These include phospholipids, glycolipids, lipoproteins, etc.

Phospholipids- triglycerides in which one fatty acid residue is replaced by a phosphoric acid residue. They take part in the formation of cell membranes.

Glycolipids- see above.

Lipoproteins- complex substances formed as a result of the combination of lipids and proteins.

Lipoids- fatty substances. These include carotenoids (photosynthetic pigments), steroid hormones (sex hormones, mineralocorticoids, glucocorticoids), gibberellins (plant growth substances), fat-soluble vitamins (A, D, E, K), cholesterol, camphor, etc.

Lipid functions

Function	Examples and explanations
Energy	The main function of triglycerides. When 1 g of lipids are broken down, 38.9 kJ is released.
Structural	Phospholipids, glycolipids and lipoproteins are involved in the formation of cell membranes.
Storing	Fats and oils are a reserve food substance in animals and plants. It is important for animals hibernating during the cold season or making long transitions through an area where there are no food sources. Plant seed oils are essential to provide energy to the seedling.
Protective	Fat layers and fat capsules provide cushioning of internal organs. Layers of wax are used as a water-repellent coating in plants and animals.
Thermal insulation	Subcutaneous adipose tissue prevents the outflow of heat into the surrounding space. Important for aquatic mammals or mammals in colder climates.
Regulatory	Gibberellins regulate plant growth. The sex hormone testosterone is responsible for the development of male secondary sex characteristics. The sex hormone estrogen is responsible for the development of female secondary sexual characteristics and regulates the menstrual cycle. Mineralocorticoids (aldosterone, etc.) control water-salt metabolism. Glucocorticoids (cortisol, etc.) are involved in the regulation of carbohydrate and protein metabolism.
Source of metabolic water	When 1 kg of fat is oxidized, 1.1 kg of water is released. Important for desert dwellers.
Catalytic	Fat-soluble vitamins A, D, E, K are enzyme cofactors, i.e. by themselves, these vitamins do not have catalytic activity, but without them enzymes cannot perform their functions.

Go to lectures number 1"Introduction. Cell chemical elements. Water and other inorganic compounds "

Go to lectures number 3“The structure and function of proteins. Enzymes "

Introduction

carbohydrates glycolipids biological

Carbohydrates are the most widespread class of organic compounds on Earth, which are part of all organisms and are necessary for the life of humans and animals, plants and microorganisms. Carbohydrates are the primary products of photosynthesis; in the carbon cycle, they serve as a kind of bridge between inorganic and organic compounds. Carbohydrates and their derivatives in all living cells play the role of a plastic and structural material, a supplier of energy, substrates and regulators for specific biochemical processes. Carbohydrates not only serve as a nutritional function in living organisms, they also have a supporting and structural function. All tissues and organs contain carbohydrates or their derivatives. They are part of the cell membranes and subcellular formations. They take part in the synthesis of many important substances.

Relevance

Currently, this topic is relevant, because carbohydrates are necessary for the body, since they are part of its tissues and perform important functions: - they are the main supplier of energy for all processes in the body (they can be broken down and give energy even in the absence of oxygen); - are necessary for the rational use of proteins (proteins with a deficiency of carbohydrates are used for other purposes: they become a source of energy and participants in some important chemical reactions); - closely related to fat metabolism (if you consume too many carbohydrates, more than can be converted to glucose or glycogen (which is deposited in the liver and muscles), the result is fat. When the body needs more fuel, fat is converted back to glucose, and body weight decreases); - the brain is especially necessary for normal functioning (if muscle tissues can accumulate energy in the form of fatty deposits, then the brain cannot do this, it entirely depends on the regular intake of carbohydrates into the body); - are an integral part of the molecules of some amino acids, are involved in the construction of enzymes, the formation of nucleic acids, etc.

Concept and classification of carbohydrates

Carbohydrates are substances with the general formula C n (H 2O) m where n and m can have different values. The name "carbohydrates" reflects the fact that hydrogen and oxygen are present in the molecules of these substances in the same ratio as in the water molecule. In addition to carbon, hydrogen and oxygen, carbohydrate derivatives may contain other elements, such as nitrogen.

Carbohydrates are one of the main groups of organic substances in cells. They are the primary products of photosynthesis and the initial products of the biosynthesis of other organic substances in plants (organic acids, alcohols, amino acids, etc.), and are also found in the cells of all other organisms. In an animal cell, the carbohydrate content is in the range of 1-2%; in plant cells, it can in some cases reach 85-90% of the dry matter mass.

There are three groups of carbohydrates:

· monosaccharides or simple sugars;

· oligosaccharides are compounds consisting of 2-10 sequentially connected molecules of simple sugars (for example, disaccharides, trisaccharides, etc.).

· polysaccharides consist of more than 10 molecules of simple sugars or their derivatives (starch, glycogen, cellulose, chitin).

Monosaccharides (simple sugars)

Depending on the length of the carbon skeleton (the number of carbon atoms), monosaccharides are divided into trioses (C 3), tetroses (C 4), pentose (C 5), hexose (C 6), heptose (C7 ).

Monosaccharide molecules are either aldehyde alcohols (aldoses) or ketalcohols (ketosis). The chemical properties of these substances are determined, first of all, by the aldehyde or ketone groups that make up their molecules.

Monosaccharides are highly soluble in water, sweet in taste.

When dissolved in water, monosaccharides, starting with pentoses, acquire a ring shape.

The cyclic structures of pentoses and hexoses are their usual forms: at any given moment, only a small fraction of the molecules exist in the form of an "open chain". The composition of oligo- and polysaccharides also includes cyclic forms of monosaccharides.

In addition to sugars, in which all carbon atoms are linked to oxygen atoms, there are partially reduced sugars, the most important of which is deoxyribose.

Oligosaccharides

When hydrolyzed, oligosaccharides form several molecules of simple sugars. In oligosaccharides, simple sugar molecules are linked by so-called glycosidic bonds that connect the carbon atom of one molecule through oxygen to the carbon atom of another molecule.

The most important oligosaccharides are maltose (malt sugar), lactose (milk sugar), and sucrose (cane or beet sugar). These sugars are also called disaccharides. By their properties, disaccharides are blocks to monosaccharides. They dissolve well in water and taste sweet.

Polysaccharides

These are high molecular weight (up to 10,000,000 Da) polymeric biomolecules, consisting of a large number of monomers - simple sugars and their derivatives.

Polysaccharides can be composed of monosaccharides of the same or different types. In the first case, they are called homopolysaccharides (starch, cellulose, chitin, etc.), in the second, heteropolysaccharides (heparin). All polysaccharides are insoluble in water and do not taste sweet. Some of them are capable of swelling and licking.

The most important polysaccharides are as follows.

Cellulose- a linear polysaccharide consisting of several straight parallel chains connected by hydrogen bonds. Each chain is formed by β-D-glucose residues. Such a structure prevents the penetration of water, is very tear-resistant, which ensures the stability of the membranes of plant cells, which contain 26-40% cellulose.

Cellulose serves as food for many animals, bacteria and fungi. However, most animals, including humans, cannot assimilate cellulose, since there is no cellulase enzyme in their gastrointestinal tract that breaks down cellulose to glucose. At the same time, cellulose fibers play an important role in nutrition, since they give food bulk and coarse texture, and stimulate intestinal motility.

Starch and glycogen... These polysaccharides are the main forms of glucose storage in plants (starch), animals, humans, and fungi (glycogen). During their hydrolysis, glucose is formed in organisms, which is necessary for vital processes.

Chitinformed by molecules of β-glucose, in which the alcohol group at the second carbon atom is replaced by a nitrogen-containing group NHCOCH 3... Its long parallel chains, like cellulose chains, are bundled. Chitin is the main structural element of the integument of arthropods and the cell walls of fungi.

Brief description of the ecological and biological role of carbohydrates

Summarizing the above material related to the characterization of carbohydrates, we can draw the following conclusions about their ecological and biological role.

1. They perform a building function, both in cells and in the body as a whole, due to the fact that they are part of the structures that form cells and tissues (this is especially characteristic of plants and fungi), for example, cell membranes, various membranes, etc. e., in addition, carbohydrates are involved in the formation of biologically essential substances that form a number of structures, for example, in the formation of nucleic acids that form the basis of chromosomes; carbohydrates are part of complex proteins - glycoproteins, which have a certain value in the formation of cellular structures and intercellular substance.

2. The most important function of carbohydrates is the trophic function, which consists in the fact that many of them are food products of heterotrophic organisms (glucose, fructose, starch, sucrose, maltose, lactose, etc.). These substances, in combination with other compounds, form food products used by humans (various cereals; fruits and seeds of individual plants, which include carbohydrates in their composition, are food for birds, and monosugar, entering into a cycle of various transformations, contribute to the formation of both its own carbohydrates, characteristic for a given organism, as well as for other organo-biochemical compounds (fats, amino acids (but not their proteins), nucleic acids, etc.).

3. For carbohydrates, the energy function is also characteristic, which consists in the fact that monosaccharides (in particular glucose) in organisms are easily oxidized (the final oxidation product is CO 2and H 2O), while a large amount of energy is released, accompanied by the synthesis of ATP.

4. They also have a protective function, consisting in the fact that structures (and certain organelles in the cell) arise from carbohydrates that protect either the cell or the body as a whole from various damages, including mechanical ones (for example, the chitinous integuments of insects that form external skeleton, cell membranes of plants and many fungi, including cellulose, etc.).

5. An important role is played by the mechanical and form-forming functions of carbohydrates, which are the ability of structures formed either by carbohydrates, or in combination with other compounds, to give the body a certain shape and make them mechanically strong; Thus, the cell membranes of the mechanical tissue and vessels of the xylem create the skeleton (internal skeleton) of woody, shrub and herbaceous plants, the external skeleton of insects is formed by chitin, etc.

Brief characteristics of the metabolism of carbohydrates in a heterotrophic organism (on the example of the human body)

An important role in understanding metabolic processes is played by knowledge about the transformations that carbohydrates undergo in heterotrophic organisms. In the human body, this process is characterized by the following schematic description.

Carbohydrates in food enter the body through the mouth. Monosaccharides in the digestive system practically do not undergo transformations, disaccharides are hydrolyzed to monosaccharides, and polysaccharides undergo significant transformations (this applies to those polysaccharides that are consumed by the body, and carbohydrates that are not food substances, for example, cellulose, some pectins, are removed from the body with feces).

In the oral cavity, food is crushed and homogenized (it becomes more homogeneous than before entering it). Food is affected by the saliva secreted by the salivary glands. It contains the enzyme ptyalin and has an alkaline reaction of the medium, due to which the primary hydrolysis of polysaccharides begins, leading to the formation of oligosaccharides (carbohydrates with a small n value).

Part of the starch can even turn into disaccharides, which can be noticed with prolonged chewing of bread (sour black bread becomes sweet).

Chewed food, abundantly processed with saliva and crushed by teeth, through the esophagus in the form of a food lump enters the stomach, where it is exposed to gastric juice with an acidic reaction of the environment containing enzymes that affect proteins and nucleic acids. Almost nothing happens in the stomach with carbohydrates.

Then the food slurry enters the first section of the intestine (small intestine), which begins with the duodenum. It receives pancreatic juice (pancreatic secretion) containing a complex of enzymes that promote the digestion of carbohydrates. Carbohydrates are converted to monosaccharides, which are water soluble and absorbable. Dietary carbohydrates are finally digested in the small intestine, and in that part of it, where the villi are contained, they are absorbed into the bloodstream and enter the circulatory system.

With the blood flow, monosugar is carried to various tissues and cells of the body, but first all blood passes through the liver (where it is cleared of harmful metabolic products). In the blood, monosugars are present mainly in the form of alpha-glucose (but other isomers of hexoses, such as fructose, are also possible).

If blood glucose is less than normal, then part of the glycogen contained in the liver is hydrolyzed to glucose. Excessive carbohydrate content characterizes a serious human disease - diabetes.

From the blood, monosaccharides enter the cells, where most of them are spent on oxidation (in mitochondria), during which ATP is synthesized, which contains energy in a form "convenient" for the body. ATP is spent on various processes that require energy (synthesis of substances necessary for the body, the implementation of physiological and other processes).

Some of the carbohydrates in food are used for the synthesis of carbohydrates of a given organism, which are required for the formation of cell structures, or compounds necessary for the formation of substances of other classes of compounds (this is how fats, nucleic acids, etc. can be obtained from carbohydrates). The ability of carbohydrates to convert into fats is one of the causes of obesity, a disease that entails a complex of other diseases.

Consequently, the consumption of an excessive amount of carbohydrates is harmful to the human body, which must be taken into account when organizing a balanced diet.

In plant organisms that are autotrophs, the metabolism of carbohydrates is somewhat different. Carbohydrates (monosaccharides) are synthesized by the body itself from carbon dioxide and water using solar energy. Di-, oligo- and polysaccharides are synthesized from monosaccharides. Some monosaccharides are involved in the synthesis of nucleic acids. Plant organisms use a certain amount of monosaccharides (glucose) in the processes of respiration for oxidation, during which (as in heterotrophic organisms) ATP is synthesized.

Glycolipids and glycoproteins as structural and functional components of the carbohydrate cell

Glycoproteins are proteins containing oligosaccharide (glycan) chains covalently attached to a polypeptide backbone. Glycosaminoglycans are polysaccharides built from repeating disaccharide components that usually contain an amino sugar (glucosamine or galactosamine in sulfonated or non-sulfonated form) and uronic acid (glucuronic or iduronic). Previously, glycosaminoglycans were called mucopolysaccharides. They are usually covalently linked to a protein; a complex of one or more glycosaminoglycans with a protein is called a proteoglycan. Glycoconjugates and complex carbohydrates are equivalent terms referring to molecules that contain carbohydrate chains (one or more) covalently linked to a protein or lipid. This class of compounds includes glycoproteins, proteoglycans, and glycolipids.

Biomedical significance

Almost all human plasma proteins, except albumin, are glycoproteins. Many cell membrane proteins contain significant amounts of carbohydrates. Substances of blood groups in some cases turn out to be glycoproteins, sometimes glycosphingolipids play this role. Some hormones (for example, chorionic gonadotropin) are glycoprotein in nature. Recently, cancer has been increasingly characterized as the result of abnormal gene regulation. The main problem of oncological diseases, metastases, is a phenomenon in which cancer cells leave their place of origin (for example, the mammary gland), are transported with the bloodstream to distant parts of the body (for example, the brain) and grow indefinitely with catastrophic consequences for the patient. Many oncologists believe that metastasis is, at least in part, due to changes in the structure of glycoconjugates on the surface of cancer cells. At the heart of a number of diseases (mucopolysaccharidosis) is insufficient activity of various lysosomal enzymes that destroy individual glycosaminoglycans; as a result, one or more of them accumulate in the tissues, causing various pathological signs and symptoms. One example of such conditions is Hurler's syndrome.

Distribution and functions

Glycoproteins are found in most organisms, from bacteria to humans. Many animal viruses also contain glycoproteins, and some of these viruses have been extensively studied, in part because of their ease of use for research.

Glycoproteins are a large group of proteins with various functions, their carbohydrate content varies from 1 to 85% or more (in units of mass). The role of oligosaccharide chains in the function of glycoproteins has not yet been precisely determined, despite the intensive study of this issue.

Glycolipids are complex lipids formed by combining lipids with carbohydrates. Glycolipid molecules have polar "heads" (carbohydrate) and non-polar "tails" (residues of fatty acids). Thanks to this, glycolipids (along with phospholipids) are part of the cell membranes.

Glycolipids are widely present in tissues, especially in nervous tissue, in particular in brain tissue. They are localized mainly on the outer surface of the plasma membrane, where their carbohydrate components are among other carbohydrates on the cell surface.

Glycosphingolipids, which are components of the outer layer of the plasma membrane, can participate in intercellular interactions and contacts. Some of them are antigens, for example, Forssman's antigen and substances that determine the blood groups of the AB0 system. Similar oligosaccharide chains are found in other plasma membrane glycoproteins. A number of gangliosides function as receptors for bacterial toxins (for example, cholera toxin, which triggers the activation of adenylate cyclase).

Glycolipids, unlike phospholipids, do not contain phosphoric acid residues. In their molecules, the residues of galactose or sulfoglucose are attached to diacylglycerol by a glycosidic bond

Hereditary metabolic disorders of monosaccharides and disaccharides

Galactosemia is a hereditary metabolic pathology caused by insufficient activity of enzymes involved in the metabolism of galactose. The inability of the body to utilize galactose leads to severe damage to the digestive, visual and nervous systems of children at a very early age. In pediatrics and genetics, galactosemia is a rare genetic disease with a frequency of one in 10,000 to 50,000 newborns. For the first time, the clinic of galactosemia was described in 1908 by a child suffering from severe malnutrition, hepato- and splenomegaly, galactosuria; at the same time, the disease disappeared immediately after the abolition of milk nutrition. Later, in 1956, the scientist Hermann Kelker determined that the disease is based on a violation of the metabolism of galactose. Causes of the disease Galactosemia is a congenital pathology inherited in an autosomal recessive manner, that is, the disease manifests itself only if the child inherits two copies of the defective gene from each of the parents. Individuals heterozygous for the mutant gene are carriers of the disease, but they may also develop some signs of mild galactosemia. The conversion of galactose to glucose (Lelloir's metabolic pathway) occurs with the participation of 3 enzymes: galactose-1-phosphaturidyl transferase (GALT), galactokinase (GALK) and uridine diphosphate-galactose-4-epimerase (GALE). In accordance with the deficiency of these enzymes, there are 1 (classic), 2 and 3 types of galactosemia. The isolation of the three types of galactosemia does not coincide with the order of action of enzymes in the metabolic pathway of Lelloir. Galactose enters the body with food, and is also formed in the intestine during the hydrolysis of lactose disaccharide. The metabolic pathway of galactose begins with its conversion under the action of the GALK enzyme to galactose-1-phosphate. Then, with the participation of the enzyme GALT, galactose-1-phosphate is converted to UDP-galactose (uridyldiphosphogalactose). After that, with the help of GALE, the metabolite is converted into UDP - glucose (uridyldiphosphoglucose). In case of insufficiency of one of these enzymes (GALK, GALT or GALE), the concentration of galactose in the blood increases significantly, intermediate galactose metabolites accumulate in the body, which cause toxic damage to various organs: the central nervous system , liver, kidneys, spleen, intestines, eyes, etc. Disturbance of galactose metabolism is the essence of galactosemia. The most common in clinical practice is the classic (type 1) galactosemia caused by a defect in the GALT enzyme and a violation of its activity. The gene encoding the synthesis of galactose-1-phosphaturidyl transferase is located in the vocal-centromeric region of the 2nd chromosome. According to the severity of the clinical course, severe, moderate and light degrees of galactosemia are distinguished. The first clinical signs of severe galactosemia develop very early, in the first days of a child's life. Soon after feeding a newborn with breast milk or formula, vomiting and upset stools (watery diarrhea) occur, and intoxication increases. The baby becomes lethargic, refuses to breast or bottle; his hypotrophy and cachexia are rapidly progressing. The child may be disturbed by flatulence, intestinal colic, profuse discharge of gas. During the examination of a child with galactosemia by a neonatologist, the fading of reflexes of the neonatal period is revealed. With galactosemia, persistent jaundice of varying severity and hepatomegaly appear early, liver failure progresses. Splenomegaly, cirrhosis of the liver, ascites occur by the age of 2-3 months. Disorders of blood coagulation processes lead to the appearance of hemorrhages on the skin and mucous membranes. Children begin to lag behind in psychomotor development early, but the degree of intellectual impairment in galactosemia does not reach such severity as in phenylketonuria. By 1-2 months in children with galactosemia, bilateral cataracts are detected. Kidney damage in galactosemia is accompanied by glucosuria, proteinuria, hyperaminoaciduria. In the terminal phase of galactosemia, the child dies from profound exhaustion, severe liver failure and accumulation of secondary infections. With galactosemia of moderate severity, vomiting, jaundice, anemia, psychomotor retardation, hepatomegaly, cataract, and malnutrition are also noted. Galactosemia of mild degree is characterized by refusal of breast, vomiting after milk intake, delayed speech development, lagging behind the child in weight and growth. However, even with a mild course of galactosemia, the metabolic products of galactose have a toxic effect on the liver, leading to its chronic diseases.

Fructosemia

Fructosemia is a hereditary genetic disorder caused by intolerance to fructose (the fruit sugar found in all fruits, berries and some vegetables, as well as honey). With fructosemia, there are few or practically no enzymes in the human body (enzymes, organic substances of a protein nature that accelerate chemical reactions in the body) that take part in the breakdown and assimilation of fructose. The disease is usually detected in the first weeks and months of a child's life or from the moment the child begins to receive juices and foods containing fructose: sweet tea, fruit juices, vegetable and fruit purees. Fructosemia is transmitted in an autosomal recessive mode of inheritance (the disease manifests itself if both parents have the disease). Boys and girls get sick equally often.

Causes of the disease

The liver contains an insufficient amount of a special enzyme (fructose-1-phosphate aldolase) that converts fructose. As a result, metabolic products (fructose-1-phosphate) accumulate in the body (liver, kidneys, intestinal mucous membranes) and have a damaging effect. At the same time, it was found that fructose-1-phosphate is never deposited in the cells of the brain and the lens of the eye. Symptoms of the disease appear after eating fruits, vegetables or berries in any form (juices, nectars, purees, fresh, frozen or dried), as well as honey. The severity of the manifestation depends on the amount of food consumption.

Lethargy, pallor of the skin. Increased sweating. Drowsiness. Vomit. Diarrhea (frequent, bulky (large portions) loose stools). Aversion to sweet foods. Hypotrophy (deficiency (insufficiency) of body weight) develops gradually. An increase in the size of the liver. Ascites (accumulation of fluid in the abdominal cavity). Jaundice (yellowing of the skin) - sometimes develops. Acute hypoglycemia (a condition in which the level of glucose (sugar) in the blood is significantly reduced) can develop with the simultaneous consumption of large quantities of foods containing fructose. It is characterized by: Trembling of the limbs; convulsions (paroxysmal involuntary muscle contractions and extreme tension); Loss of consciousness up to coma (lack of consciousness and reaction to any stimuli; the condition poses a danger to human life).

Conclusion

The importance of carbohydrates in human nutrition is very great. They serve as an essential source of energy, providing up to 50-70% of the total calorie intake.

The ability of carbohydrates to be a highly efficient energy source underlies their "protein-saving" action. Although carbohydrates are not among the essential nutritional factors and can be formed in the body from amino acids and glycerin, the minimum amount of carbohydrates in the daily diet should not be less than 50-60 g.

A number of diseases are closely related to the disturbance of carbohydrate metabolism: diabetes mellitus, galactosemia, disturbance in the glycogen depot system, milk intolerance, etc. It should be noted that in humans and animals, carbohydrates are present in smaller quantities (no more than 2% of dry body weight) than proteins and lipids; in plant organisms, due to cellulose, carbohydrates account for up to 80% of the dry mass, therefore, in general, there are more carbohydrates in the biosphere than all other organic compounds combined.Thus: carbohydrates play a huge role in the life of living organisms on the planet, scientists believe that approximately when the first carbohydrate compound appeared, the first living cell appeared.

Literature

1. Biochemistry: textbook for universities / ed. E. S. Severina - 5th ed., - 2009 .-- 768 p.

2.T.T. Berezov, B.F. Korovkin "Biological chemistry".

3. P.A. Verbolovich "Workshop on organic, physical, colloidal and biological chemistry."

4. Leinger A. Fundamentals of Biochemistry // M .: Mir, 1985

5. Clinical endocrinology. Management / N. T. Starkova. - 3rd edition, revised and enlarged. - St. Petersburg: Peter, 2002 .-- S. 209-213. - 576 p.

6. Children's diseases (volume 2) - N.P. Shabalov. - textbook, Peter, 2011

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What kind of food makes you personally happy? Let me guess: a light fruit-yogurt cake with fragrant tea or an airy Raffaello presented to your loved ones? Or maybe you are one of those who like to feast on morning oatmeal with a handful of dried fruits, and dine on expensive Italian pasta with seafood and cheese? If somewhere you recognized yourself, then this article will definitely be useful for you, since today we will talk about your favorite products, or rather, one category of products called CARBOHYDRATES. Of course, you are already "advanced" in matters of proper nutrition and already know a lot, but, as they say, "repetition is the mother of learning." Today we will take a closer look at what is simple and complex carbohydrates; what functions do carbohydrates perform in our body, and why do we need them at all; what kind carbohydrates for weight loss is it preferable to use and why? I really hope that after reading this article, many of you will reconsider your diet and understand that excessive intake of carbohydrates, as well as insufficient, can cause many health problems.

Well, I propose to start with the basics and find out what carbohydrates are, and what functions do they carry for a person?

Carbohydrates and their functions

Carbohydrates are a vast class of organic compounds that are the main source of energy for many living organisms on the planet, including humans. Sources of carbohydrates are mainly plant foods (cereals, plants, vegetables and fruits), since it is plants that participate in the processes of photosynthesis, during which carbohydrates are formed, but small amounts of carbohydrates are also contained in protein products - fish, meat and dairy products.

So, what functions do carbohydrates perform in the human body?

I will not list all the functions, I will name only the main ones that are of greatest interest to us.

Of course it is energy function... When you consume 1 g of carbohydrates, 4 kcal of energy are released.
Storing- carbohydrates can be stored in the human body in the form of glycogen and, under suitable conditions, can be used as energy (see item 1)
Protective- being in the liver, carbohydrates help it to neutralize poisonous and toxic substances that have entered the body from the outside.
Plastic- are part of the molecules, and are also stored in the form of nutrient reserves.
Regulatory- regulate the osmotic pressure of the blood.
Antidepressant- carbohydrates can trigger the release of serotonin, the hormone of good mood.

Lack of carbohydrates: consequences

For those involved in sports, the main function is energy. It is thanks to her that we can be active, we can go to the gym after a hard day's work, work out there for an hour and a half, and then come home and cook dinner for the whole family. If there were no carbohydrates in our diet, then all people would walk like zombies, barely moving their legs, but at the same time they would be angry, like dogs, ready at any moment to pounce on the first victim they come across and tear it to pieces. If you've ever sat on or stuck to, then you surely know what I'm talking about. On those days when carbohydrates in the diet make up less than 15% of the daily intake of BZHU (on average, this is<60-50 г углеводов в день), в организме человека начинают происходить удивительные вещи:

- the mood falls "below the plinth";

- lethargy and fatigue appear throughout the body;

- productivity falls;

- human energy resources are decreasing;

- mental and thought processes slow down;

- some have a drowsy melancholic mood, while others, on the contrary, are aggressive and nervous.

All of these signs are the consequences of inadequate carbohydrate intake. If you have never felt these effects on yourself, then a) you have never lost weight using extreme types of diets (which is very good) and b) you eat as much carbs as you want, and do not worry about your weight. If you classified yourself as b-categories, which means, most likely, there is such a problem in your diet as an OVER-EXCESS OF CARBOHYDRATES. And now we will dwell on this issue in more detail.

Where are carbohydrates stored?

I think now it's not a secret for anyone that with carbohydrates for weight loss you need to be extremely careful, they can greatly inhibit the process of fat burning due to their unique ability to be stored in the form of fat. The fact is that any food entering our body must be processed and assimilated, and the energy released during this must go to the body's energy costs. If you have consumed too much food at one time, then most of it will go to the fat depot. If we talk about carbohydrates, then only 5% of carbohydrates will be burned for the current needs of the body (for the nutrition of cells with energy, the work of the brain, heart and other organs and systems), another 5% will be stored in the form of glycogen in the liver and muscle tissue, and the remaining 90% will go in FAT! And believe me, hoarding and simple and complex carbohydrates according to this scheme, it happens EVERY TIME when you sit in front of the computer and drink tea with sweets, or at 10 o'clock in the evening you decided to have dinner with buckwheat and milk.

At this moment, your body does not need energy, which means that the burning of calories will not occur! What for? - after all, you are sitting straight on the chair, spending the minimum amount of energy on this process. It turns out that your body has nowhere to spend the energy received from carbohydrates ... There is only one way out - to send all received carbohydrates to the fat depot for storage until "better" times.

 A short excursion into history

Previously, our long-term ancestors did not have such an abundance of refined carbohydrates in the form of flour products, industrial confectionery, sugar-containing foods and other sources of fast carbohydrates, and the consumption of starchy foods such as potatoes, legumes and cereals was a small part of their daily diet. The diet of the first people was mainly based on animal protein, and a little later, with the development of gathering, the diet was enriched with roots, plants and berries. Why am I telling all this? And to the fact that our body has changed little since that time, and our needs for simple and complex carbohydrates remained the same as they were millions of years ago. Yes, people have become more developed in comparison with the primitive people of the Stone Age, this is a fact, but the body's needs for carbohydrates did not increase, but, on the contrary, DECREASED due to more a sedentary and less active lifestyle.

But who thinks about it? I think there are not many such people. And all because at every step, in every store and stall, wonderful carbohydrates in the form of various sweets are looking at us - how can you resist them ???

Excess carbohydrates: consequences

The main function of carbohydrates is to provide us with energy with which we can lead a normal active life. But when there are too many carbohydrates in a person's diet, this is where problems begin, the main ones of which are:

- overweight / obesity;

- violation of carbohydrate metabolism in the body;

- development of atherosclerosis;

- diseases of the gastrointestinal tract: diarrhea, impaired absorption of nutrients, dysbiosis, intestinal dysbiosis, the development of pathogenic microflora in the intestine, etc.)

- metabolic and hormonal disorders: sleep disturbances, frequent headaches, irritability, fatigue, memory impairment, etc.

- weakening of the immune system;

- the development of insulin resistance (insensitivity), which can lead to the development of diabetes mellitus.

These are far from all the negative consequences of an excess of carbohydrates, there are MUCH more of them, and all of them can manifest themselves at any time if you do not stop consuming large amounts of carbohydrate foods.

Of course, few people think about bowel disease or sleep disturbance when they eat their favorite dessert, this is obvious. Most people, until they are faced with some serious illness face to face and necessarily already in an acute form, no one will think in advance to worry about their health and reconsider their diet, this is our essence, unfortunately ...

But what are the optimal consumption rates simple and complex carbohydrates? Since few carbohydrates are bad, and a lot is also bad, then how to find this "golden mean" when everyone is good?

Simple and complex carbohydrates

When we talk about carbohydrates, we need to understand that there are two types of carbohydrates - these are simple and complex carbohydrates. Their main difference is the indicator. Simple carbohydrates basically all have a high glycemic index and consist of mono- and disaccharides, while complex carbohydrates have medium and low GI and contain poly- and oligosaccharides.

 For your reference:

The glycemic index is a measure of the digestibility of carbohydrates. The higher the GI of a product, the faster the carbohydrates from this product will be absorbed by the body, and the faster the blood sugar level will rise. And with a sharp increase in blood sugar, the pancreas reacts with a powerful release of insulin, which instantly distributes this sugar through the cells of our body, and if they do not need this sugar, then insulin directs it to adipose tissue, which takes everything with great pleasure and willingness. what is offered to her.

To make it clearer, let's look at the example of products, which carbohydrates are fast and which are slow.

Simple carbohydrates

Simple carbohydrates are divided into monosaccharides and disaccharides. Monosaccharides consist of one sugar group - glucose, fructose and galactose, and disaccharides consist of two molecules of simple sugars - sucrose, maltose and lactose, which always include glucose.

1. Glucose- it is the main source of energy for the body and nutrition of our brain. Glucose is involved in storing glycogen, which is nothing more than a polymer of glucose and is also used by the body as fuel throughout the day and during strength training.

Glucose-rich foods:

- carrot;

- gingerbread;

- dates;

- jam;

- corn;

- cherries.

2. Galactose- This is a molecule that is part of lactose, but does not occur in free form.

3. Fructose Is a natural sugar. Most of the fructose in these fruits:

- Strawberry;

- bananas;

Although fructose is a natural sugar, this does not make it completely harmless. You can read more about the mechanism of action of fructose in this article:

Monosaccharides are followed by disaccharides, which already consist of two molecules of the sugar group.

4. Sucrose Is a compound of glucose and fructose. Sucrose rich foods:

- jam;

5. Lactose contains one glucose molecule and one galactose molecule. Basically, dairy products are rich in lactose, which is why dairy products should be eaten in very limited quantities when losing weight, since lactose tends to cause fermentation in the intestines and swelling.

Lactose-rich foods:

- milk;

- cottage cheese;

- milk;

- fermented baked milk;

6. Maltose Are two glucose molecules. There is a lot of maltose in such products:

- marmalade;

- syrup (starch, caramel, beetroot, etc.);

- ice cream;

So, the main thing that you should remember about simple carbohydrates is that simple carbohydrates quickly increase the concentration of glucose in the blood, for this the pancreas produces the hormone insulin, and all the cells of the body immediately open to assimilate glucose. If at this moment you do not move, but sit still, then all the glucose is not used by cells, but goes straight to the fat depot! If you move (walk, swim, run, dance), then the energy received from carbohydrates will be burned to cover the current energy consumption of the body.

Therefore, we remember rule number 1:

IF YOU WANT TO EAT SIMPLE CARBOHYDRATES AND DO NOT GET IT, YOU MUST MOVE !!!

The rate of simple carbohydrates per day

The amount of simple carbohydrates per day should be no more than 30% of the total amount of carbohydrates eaten.

For example, your daily carbohydrate intake is 140 g. , which means that simple carbohydrates account for 42 g. So many simple carbohydrates contain:

- 1 persimmon;

- 2 large apples;

- 2 medium oranges;

- 2 pears;

- 500 g cherries;

- 600 g of strawberries;

- 90 g of dried apricots;

- 80 g of raisins;

- 50 g of dates;

- 30 g honey (2 tablespoons)

Complex carbohydrates

Complex carbohydrates are starch, which is found mainly in cereals and legumes, and fiber, which is the basis of all vegetables and fruits.

1. Starch and the process of its assimilation

Some foods have a lot of starch, which is why they have a high GI, while others have less, which makes them slower carbohydrates that take a long time to digest, and blood sugar rises over time.

Among the "insidious" complex carbohydrates is white rice, it has a starch content of as much as 80% !!! For comparison, in oatmeal the starch content is 50%, in - 45%, in wheat flour - 74%, in pasta - 70%, in buckwheat - 60%, in lentils and barley - 40%. That is, it turns out that rice theoretically belongs to slow carbohydrates, since it contains starch polysaccharide, but in practice it behaves like a fast carbohydrate, due to the excessively high content of this very starch.

What explains this mechanism?

The fact is that during swelling, one starch molecule attracts from 10 to 100 water molecules. And the more the molecule is watered, the more ACCESSIBLE for the body it becomes! This is due to the enzyme amylase, which breaks down starch. Amylase acts only in the aqueous phase, and if the starch molecule is well hydrolyzed (ringed), then the amylase penetrates into it very quickly, and active decomposition of starch into glucose molecules occurs, hence the level of glucose in the blood rises rapidly. That is: the more the starch is hydrolyzed, the higher the GI of the cereal, and the faster the sugar enters the bloodstream, causing the release of insulin.

Personally, I do not know people who eat steamed white rice (as opposed to oatmeal and buckwheat), usually it is all cooked over low heat for about 30-40 minutes, which means that the starch molecules that rice contains are highly watery, which makes this carbohydrate readily available, which means that fat deposition is more likely.

Hence, we can conclude that for each cereal, depending on the method of its preparation, the glycemic index changes. Let's take oatmeal as an example and consider its glycemic index depending on the different cooking methods.

Option number 1 Oatmeal soaked overnight has the lowest GI (less than 50)

Option number 2 Oatmeal soaked overnight, and brought to a boil in the morning and immediately removed from the heat, has a GI just above 50.

Option number 3 Flattened oatmeal, filled with boiling water for 5 minutes, has an even lower GI than option No. 1.

Option number 4 Boiled oatmeal in milk for 5-10 minutes has a high GI (around 60)

Option number 5 Cooked oatmeal with sugar / honey / syrup has a GI of 100 like sugar.

Option number 6 Oatmeal, which is part of a pie or pancakes, has a GI over 100.

From here we can conclude: all complex carbohydrates can turn into fast depending on the:

1) method of preparation - the more time the cereal is exposed to high temperatures (cooking, stewing, baking, frying), the faster the hydrolysis (watering) of starch proceeds, and the more quickly it becomes available.

2) adding other foods (honey, sugar, milk, etc.) - if you add any ingredient to your cereal, the glycemic index of which is higher than that of this cereal, then you automatically turn your slow carbohydrate into a fast one.

So remember rule number 2:

IF YOU WANT TO BE SLIM, THEN TREAT ALL DIFFICULT CARBOHYDRATES MINIMALLY!

The same goes for vegetables: if you are boiling / stewing vegetables, do not keep them in water for too long.

Sources of complex carbohydrates containing starch:

Tab. 1 Starchy foods (starch content in% per 100 g)

The rate of consumption of starchy foods per day

Complex carbohydrates should account for about 40% of the daily value of all carbohydrates.

40% of 140 g = 56 g. That is, it turns out that on average you should eat about 56 g of starchy carbohydrates per day, if your total carbohydrate intake is 140 g.

56 g of complex carbohydrates are found in:

- 85 g of dry oatmeal;

- 270 g of boiled brown rice;

- 285 g of boiled beans;

- 330 g of buckwheat porridge.

2. Fiber and the mechanism of its assimilation

Fiber is mainly found in fruits and vegetables. If we talk about complex carbohydrates, then we will mean only vegetables, since they contain ten times less sugar than fruits. Fiber is not assimilated by the body, and therefore in transit passes through the entire gastrointestinal tract, clearing it of various debris and toxins. Fiber is a very important component of a healthy and proper diet, therefore its presence in the daily human diet is essential. The rate of fiber per day ranges from 20 to 45 grams. To gain your daily fiber intake, you need to consume on average 500 to 1 kg of fresh or stewed vegetables + 150-200 grams of fiber-rich cereals (oatmeal, buckwheat, barley, legumes) per day.

Sources of fiber:

- vegetables with a low GI are preferable: cucumbers, all types of cabbage, asparagus, green beans, radishes, zucchini, greens, etc.

- fewer vegetables with an average GI: tomatoes, peas, bell peppers, mushrooms.

Fiber intake per day

Fiber, as well as simple carbohydrates, should get 30% of the total amount of carbohydrates eaten per day.

30% of 140g = 42g.

42 grams of fiber are found in:

- 4 medium avocados;

- 10 bananas;

- 8 medium apples;

- 100 g of bran;

- 1.5 kg of broccoli or white cabbage;

- 1.6 kg of apples;

- 500 g of peanuts.

Now let's look at how to calculate these same TOTAL daily grams of all carbohydrates.

Table 2 shows the number of calories and the amount of all carbohydrates per day, depending on your lifestyle (sedentary, moderately active, very active). These norms are designed for a low-carbohydrate diet that is suitable for endomorph girls, whose goal is to reduce the fat content.

Tab. 2 Low Carb Corrective Diet: Caloric Maintenance and Recommended Carbohydrate Intakes

For example, a girl weighing 69 kg wants to lose 5 kg, while she has a sedentary job and leads a sedentary lifestyle. Opposite her weight (we take the closest in value 68 kg) there is a figure of 98 g simple and complex carbohydrates... And in order to, she must adhere to the norms of carbohydrate consumption according to the desired weight - in her case, it is 91 g, which corresponds to 64 kg.

This is about a low-carb diet that is suitable for girls with a predisposition to overweight.

If you have already lost weight and want to consolidate this result, keeping your weight at one point, then a moderately carbohydrate diet is suitable for you, where there will be completely different indicators and norms of carbohydrate consumption (Table 3).

Tab. 3 Moderate Carbohydrate Diet: Caloric Maintenance and Recommended Carbohydrate Intakes

The carbohydrates column is divided into 2 columns - 33% and 40%. The first column shows the lower limit for carbohydrate intake, and the second - the upper one. Here you simply select the value that is opposite to your current weight and stick to it - everything is very simple.

Timing of carbohydrate intake

Both simple and complex carbohydrates give the body energy. We usually need energy in the morning. Morning and lunchtime are the most active hours for many people, which is why we need a lot of energy during the day. By the evening, the energy consumption of our body decreases, and the metabolism slows down. This happens in 90% of people who work and are awake during the daytime, with the exception of people who study or work in the evening, as well as ectomorphic people, their metabolism and biological clock are slightly different from ours with you. But if you do not belong to the second group, then your metabolism in the evening is always lower than in the daytime, this has long been proven and known to everyone. It is for this reason that all nutritionists and nutritionists recommend to consume ALL carbohydrates - both simple and complex - in the morning, until about 16-00.

If you have a good metabolism, and you, on the contrary, find it difficult to gain weight, then you can eat carbohydrates even for dinner.

What to combine simple and complex carbohydrates with?

We already know that the absorption rate of slow carbs depends on how you cook them and how they are combined with other foods, and the same goes for fast carbs. In order for food to be properly absorbed and not cause disturbances in digestion processes, you need to know what is best to combine with simple and complex carbohydrates.

Oatmeal is best cooked / steamed not in milk, but in water. Due to the fact that it is very high (AI of milk - 90), when they enter the body, a powerful release of insulin takes place, which directs all eaten carbohydrates (this is the milk sugar lactose contained in milk and starch from oatmeal) straight to the fat depot ... The same applies to the beloved by many buckwheat porridge with milk. From a complex carbohydrate, the addition of milk makes it simple and quickly digestible. That is why the combination "Complex carbohydrates + dairy products" is UNACCEPTABLE neither for weight loss nor for maintaining normal weight. The exception is mass collection. If, on the contrary, you are by nature a thin physique, and it is difficult for you to gain weight, then porridge with milk is your savior.

Sami simple and complex carbohydrates they combine well with each other, you just need to do it right. For all those who love the sweet version of oatmeal in the morning, on a note: it is best to combine oatmeal with an apple or berries (strawberries, raspberries, currants) and never eat oatmeal with ORANGE, GRAPEFRUIT, TANGERINS and PINEAPPLE! These fruits contain a lot of citric acid, which actually stops the digestion of oatmeal starch! Such a breakfast will ferment in your intestines for a long time, causing bloating, gas formation, diarrhea and other unpleasant consequences up to vomiting. I felt all of them on myself when I lived in Thailand and ate oatmeal with pineapple in the morning. This went on day after day for 6 months. And all these six months I had problems with my gastrointestinal tract ... I would not wish anyone what I felt almost every day: sharp cutting pains in the abdomen, flatulence, diarrhea, etc., but at that time I did not understand why this reaction. Of course, I had guesses that this pineapple had such an effect on me, but I didn’t want to realize this, because I really love pineapples and before leaving home I wanted to eat them for several years in advance))) So you should know: citrus fruits are very poorly combined with favorite cereals, and if you like to eat sweet porridge, then choose safe fruits with a small amount of citric acid for this.

Simple carbohydrates in the form of sweet fruits or dried fruits, it is better not to use it with cottage cheese, since cottage cheese is a complex protein, and it is highly undesirable to combine protein foods with simple sugars. If you add banana, dates, melon to the curd, then this sweet curd-fruit mass will begin to ferment in the intestines and interfere with the absorption of all useful micro- and macro-nutrients. Cottage cheese goes well with fiber, herbs and vegetable fats (nuts, avocados,).
Fiber, which is found in vegetables, goes well with both complex carbohydrates and simple ones, and even better with proteins. So vegetables can be eaten with cereals, and with meat, and with dairy products. It is only better to give preference to low-starchy vegetables that have a low glycemic index.

Now you know how and with what it is better to combine simple and complex carbohydrates, and if you remember these four rules, then you will never have problems with digestion, and the process of losing weight you will go much more efficiently.

Well, now let's summarize all of the above:

— complex and simple carbohydrates must be consumed in optimal amounts daily! For weight loss, the rate of carbohydrates should be 20-25% of the daily calorie intake, to maintain normal weight - 33-40%.

- for normal digestion, you need to correctly combine carbohydrates with other foods: simple carbohydrates in the form of fiber go well with complex carbohydrates and proteins; porridge can be combined with unsweetened fruits and berries (apple, kiwi, raspberry); fruit is undesirable to combine with proteins (cottage cheese with fruit is a bad combination).

- it is best not to cook porridge, but to steam it, or cook it for a short time (15-20 minutes).

- Give preference to fruits and vegetables with a low glycemic index, they do not cause a sharp rise in blood sugar and are absorbed more slowly by the body.

— simple and complex carbohydrates consume in the following proportion: 20-30% simple carbohydrates, 30% fiber and 40-50% complex carbohydrates.

Hopefully these tips will help you manage carbohydrates throughout the day and get the most out of your carbohydrate intake without compromising your shape or health. Simple and complex carbohydrates can be both your friends and enemies, it all depends on their amount in your daily diet. And I wish you to find this golden mean, which will bring you closer to your goal!

Yours sincerely, Yanelia Skripnik!

The structure of biological molecules is based on the ability of carbon atoms to form covalent bonds, usually with carbon, oxygen, hydrogen or nitrogen atoms. The molecules can be in the form of long chains or form ring structures.

Among the organic molecules that make up the cell, carbohydrates, lipids, proteins, nucleic acids are isolated.

Carbohydrates - these are polymers that are formed from monosaccharides by glycosidic linkage. Monosaccharides combine by condensation (the reaction is accompanied by the release of a water molecule).

Carbohydrates are divided into simple (monosaccharides) and complex (polysaccharides). Among monosaccharides, according to the number of carbon atoms, trioses (3C), tetroses (4C), pentose (5C), hexose (6C), heptose (7C) are distinguished. In solutions, pentose and hexose can take a cyclic form.

Two monosaccharide molecules combine with each other to release a water molecule and form a disaccharide. Typical examples of disaccharides are sucrose (glucose + fructose), maltose (glucose + glucose), lactose (galactose + glucose). Disaccharides are similar in properties to monosaccharides. They dissolve well in water and taste sweet.

If the amount of monosaccharides is increased, then the solubility decreases, and the sweet taste disappears.

Monosaccharides that are often found in nature are glyceraldehyde, ribose, ribulose, deoxyribose, fructose, galactose.

Glyceric aldehyde is involved in photosynthesis reactions. Ribose is part of RNA, ATP. Deoxyribose is part of the DNA. Ribulose is not found in its pure form in nature, and its phosphorus ester is involved in photosynthesis reactions. Fructose is involved in the transformation of starch. Galactose is part of lactose.

Polysaccharides that are often found in nature are starch, glycogen, cellulose, chitin, inulin.

Starch is composed of two α-glucose polymers. Glycogen is a polymer of α-glucose. It is a storage nutrient in animal cells. Cellulose is a β-glucose polymer. It is part of the cell wall of plants. Cellulose is composed of parallel chains that are linked by hydrogen bonds. This cross-linking prevents water penetration. Cellulose is very resistant to hydrolysis and is a structural molecule.

End of work -

This topic belongs to the section:

Modern methods of cell research

Electron microscopy .. physicists have suggested using electrons instead of a beam of light .. a transmission electron microscope ..

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