Scientists have proven that sucrose is an integral part of all plants. The substance is found in large quantities in sugar cane and sugar beets. The role of this product is quite large in the diet of every person.

Sucrose belongs to the group of disaccharides (included in the class of oligosaccharides). Under the action of its enzyme or acid, sucrose breaks down into fructose (fruit sugar) and glucose, which makes up most of the polysaccharides.

In other words, sucrose molecules are composed of D-glucose and D-fructose residues.

The main product available, serving as the main source of sucrose, is ordinary sugar, which is sold in any grocery store. The science of chemistry denotes the sucrose molecule, which is an isomer, as follows - C 12 H 22 O 11.

Interaction of sucrose with water (hydrolysis)

C 12 H 22 O 11 + H 2 O → C 6 H 12 O 6 + C 6 H 12 O 6

Sucrose is considered the most important of the disaccharides. From the equation it can be seen that the hydrolysis of sucrose leads to the formation of fructose and glucose.

The molecular formulas of these elements are the same, but the structural ones are completely different.

Fructose - CH 2 - CH - CH - CH - C - CH 2.

Glucose - CH 2 (OH) - (CHOH) 4 -SOH.

Sucrose and its physical properties

Sucrose is sweet, colorless crystals that are readily soluble in water. The melting point of sucrose is 160 ° C. When molten sucrose solidifies, an amorphous transparent mass is formed - caramel.

Sucrose properties:

1. This is the most important disaccharide.
2. Does not apply to aldehydes.
3. When heated with Ag 2 O (ammonia solution) it does not give a "silver mirror" effect.
4. When heated with Cu (OH) 2 (copper hydroxide), no red copper oxide appears.
5. If you boil a solution of sucrose with a few drops of hydrochloric or sulfuric acid, then neutralize it with any alkali, then heat the resulting solution with Cu (OH) 2, you can observe the precipitation of a red precipitate.

Composition

The composition of sucrose, as you know, includes fructose and glucose, more precisely, their residues. Both of these elements are closely connected to each other. Of the isomers with the molecular formula C 12 H 22 O 11, the following should be distinguished:

• milk sugar ();
• malt sugar (maltose).

Foods containing sucrose

• Irga.
• Medlar.
• Pomegranates.
• Grape.
• Sun-dried figs.
• Raisins (raisins).
• Persimmon.
• Prunes.
• Apple pastila.
• The straws are sweet.
• Dates.
• Gingerbread.
• Marmalade.
• Bee honey.

How sucrose affects the human body

Important! The substance provides the human body with a full-fledged supply of energy, which is necessary for the functioning of all organs and systems.

Sucrose stimulates the protective functions of the liver, improves brain activity, and protects a person from the effects of toxic substances.

It supports the activity of nerve cells and striated muscles.

For this reason, the element is considered the most important among those found in almost all foods.

If the human body is deficient in sucrose, the following symptoms can be observed:

• prostration;
• lack of energy;
• apathy;
• irritability;
• depression.

Moreover, the state of health can gradually deteriorate, so you need to normalize the amount of sucrose in the body in time.

High sucrose levels are also very dangerous:

1. itching of the genitals;
2. candidiasis;
3. inflammatory processes in the oral cavity;
4. periodontal disease;
5. overweight;
6. caries.

If the human brain is overloaded with active mental activity or the body has been exposed to toxic substances, the need for sucrose increases dramatically. Conversely, this need decreases if a person is overweight or has diabetes.

How glucose and fructose affect the human body

As a result of the hydrolysis of sucrose, glucose and fructose are formed. What are the main characteristics of both of these substances, and how do they affect human life?

Fructose is a type of sugar molecule and is found in large quantities in fresh fruits, giving them sweetness. In this regard, it can be assumed that fructose is very beneficial, as it is a natural component. Fructose, which has a low glycemic index, does not increase blood sugar concentration.

The product itself is very sweet, but it is included in the composition of fruits known to man only in small quantities. Therefore, only a minimal amount of sugar gets into the body, and it is instantly processed.

However, you should not introduce large amounts of fructose into your diet. Its unreasonable use can provoke:

• fatty liver;
• scarring of the liver - cirrhosis;
• obesity;
• heart diseases;
• diabetes;
• gout;
• premature aging of the skin.

The researchers concluded that, unlike glucose, fructose induces the signs of aging much faster. It makes no sense at all to talk about its substitutes in this regard.

Based on the foregoing, we can conclude that the use of fruits in reasonable quantities for the human body is very useful, since they contain a minimum amount of fructose.

Like fructose, glucose is a type of sugar and the most abundant form of carbohydrates. The product is obtained from starches. Glucose provides the human body, in particular its brain, with a supply of energy for quite a long time, but significantly increases the concentration of sugar in the blood.

Note! If you regularly eat foods that are difficult to process or simple starches (white flour, white rice), your blood sugar will rise dramatically.

Problems:

• diabetes;
• non-healing wounds and ulcers;
• high blood lipids;
• damage to the nervous system;
• renal failure;
• overweight;
• coronary heart disease, stroke, heart attack.

Sucrose is an organic substance, more precisely a carbohydrate, or disaccharide, which consists of the residual parts of glucose and fructose. It is formed in the process of splitting off water molecules from high-grade sugars.

The chemical properties of sucrose are very diverse. As we all know, it is soluble in water (due to this we can drink sweet tea and coffee), as well as in two types of alcohols - methanol and ethanol. But at the same time, the substance completely retains its structure when exposed to diethyl ether. If sucrose is heated by more than 160 degrees, then it turns into ordinary caramel. However, with sudden cooling or strong exposure to light, the substance may begin to glow.

In reaction with copper hydroxide solution, sucrose gives a bright blue color. This reaction is widely used in various factories to isolate and purify the "sweet" substance.

If an aqueous solution containing sucrose in its composition is heated and exposed to certain enzymes or strong acids, this will lead to the hydrolysis of the substance. This reaction produces a mixture of fructose and glucose called "inert sugar". This mixture is used to sweeten various products to make artificial honey, for the production of caramelized molasses and polyhydric alcohols.

Metabolism of sucrose in the body

Sucrose in unchanged form cannot be fully assimilated in our body. Its digestion begins in the mouth with the help of amylase, an enzyme that is responsible for the breakdown of monosaccharides.

First, the substance is hydrolyzed. Then it enters the stomach, then into the small intestine, where, in fact, the main stage of digestion begins. The enzyme sucrase catalyzes the breakdown of our disaccharide into glucose and fructose. Next, the pancreatic hormone insulin, which is responsible for maintaining normal blood sugar levels, activates special carrier proteins.

These proteins transport the monosaccharides obtained during hydrolysis into enterocytes (the cells that make up the wall of the small intestine) due to facilitated diffusion. Another type of transport is also distinguished - active, due to which glucose also penetrates into the intestinal mucosa due to the difference with the concentration of sodium ions. Interestingly enough, the mode of transport depends on the amount of glucose. If there is a lot of it, then the mechanism of facilitated diffusion predominates, if there is little, then active transport.

After being absorbed into the bloodstream, our main "sweet" substance is divided into two parts. One of them enters the portal vein and then into the liver, where it is stored in the form of glycogen, and the second is absorbed by the tissues of other organs. In their cells, a process called "anaerobic glycolysis" takes place with glucose, as a result of which molecules of lactic acid and adenosine triphosphoric acid (ATP) are released. ATP is the main source of energy for all metabolic and energy-consuming processes in the body, and lactic acid in excess of it can accumulate in the muscles, which causes pain.

This is most often seen after increased physical training due to increased glucose consumption.

Functions and norms of consumption of sucrose

Sucrose is a compound without which the existence of the human body is impossible.

The compound participates in both reactions providing energy and chemical metabolism.

Sucrose ensures the normal course of many processes.

For example:

• Maintains normal blood cells;
• Provides vital activity and work of nerve cells and muscle fibers;
• Participates in the storage of glycogen - a kind of glucose depot;
• Stimulates brain activity;
• Improves memory;
• Maintains the normal condition of the skin and hair.

With all of the above beneficial properties, you need to consume sugar correctly and in small quantities. Naturally, sugary drinks, soda, various pastries, fruits and berries are also taken into account, because they also contain glucose. There are certain norms for the use of sugar per day.

For children aged one to three years, no more than 15 grams of glucose is recommended, for older children under 6 years old, no more than 25 grams, and for a full-fledged body, the daily dose should not exceed 40 grams. 1 teaspoon of sugar contains 5 grams of sucrose, which is equivalent to 20 kilocalories.

With a lack of glucose in the body (hypoglycemia), the following manifestations occur:

1. frequent and prolonged depression;
2. apathetic states;
3. increased irritability;
4. lightheadedness and dizziness;
5. migraine-type headaches;
6. the person gets tired quickly;
7. mental activity becomes inhibited;
8. hair loss is observed;
9. depletion of nerve cells.

It should be remembered that the need for glucose is not always the same. It increases with intensive intellectual work, since more energy is required to ensure the functioning of nerve cells, and with intoxication of various origins, because sucrose is a barrier that protects liver cells with sulfuric and glucuronic acids.

The negative effect of sucrose

Sucrose, breaking down into glucose and fructose, also forms free radicals, the action of which interferes with the performance of their functions by protective antibodies.

An excess of free radicals reduces the protective properties of the immune system.

Molecular ions suppress the immune system, which increases susceptibility to any infection.

Here is an approximate list of the negative effects of sucrose and their characteristics:

• Violation of mineral metabolism.
• Enzyme activity decreases.
• In the body, the amount of necessary microelements and vitamins decreases, which can lead to the development of myocardial infraction, sclerosis, vascular disease, and thrombosis.
• Increased susceptibility to infections.
• Acidification of the body occurs and, as a result, acidosis develops.
• Calcium and magnesium are not absorbed in sufficient quantities.
• The acidity of gastric juice increases, which can lead to gastritis and peptic ulcer disease.
• With pre-existing diseases of the gastrointestinal tract and lungs, their exacerbation may occur.
• The risk of developing obesity, helminthic invasions, hemorrhoids, emphysema increases (emphysema is a decrease in the elastic capacity of the lungs).
• In children, the amount of adrenaline increases.
• There is a high risk of developing coronary heart disease and osteoporosis.
• Cases of caries and periodontal disease are very common.
• Children become lethargic and sleepy.
• Systolic blood pressure rises.
• Due to the deposition of uric acid salts, gout attacks can be disturbing.
• Promotes the development of food allergies.
• Depletion of work (islets of Langerhans), as a result of which insulin production is disrupted and conditions such as impaired glucose tolerance and diabetes mellitus may occur.
• Toxicosis of pregnant women.
• By changing the structure of collagen, early gray hairs break through.
• Skin, hair and nails lose their shine, strength and elasticity.

To minimize the negative effect of sucrose on your body, you can switch to the use of sugar substitutes, such as Sorbitol, Stevia, Saccharin, Cyclamate, Aspartame, Mannitol.

It is best to consume natural sweeteners, but in moderation, as their excess can lead to the development of profuse diarrhea.

Where is sugar contained and how is it obtained?

Sucrose is found in foods such as honey, grapes, prunes, dates, yerga, marmalade, raisins, pomegranate, gingerbread, apple candy, figs, medlar, mango, corn.

The procedure for obtaining sucrose is carried out according to a certain scheme. It is obtained from sugar beets. First, the beets are peeled and cut very finely in special machines. The resulting mass is laid out in diffusers, through which boiling water is subsequently passed. With this procedure, most of the sucrose is removed from the beets. Lime milk (or calcium hydroxide) is added to the resulting solution. It promotes the precipitation of various impurities into the sediment, or rather, calcium saccharate.

For its complete and thorough precipitation, carbon dioxide is passed through. After all, the remaining solution is filtered and evaporated. As a result, a slightly yellowish sugar is released, since it contains dyes. To get rid of them, you need to dissolve sugar in water and pass it through activated charcoal. The resulting product is evaporated again and real white sugar is obtained, which is subject to further crystallization.

Where is sucrose used?

Uses sucrose:

1. Food industry - sucrose is used as a separate product for the diet of almost every person, it is added to many dishes, used as a preservative, to remove artificial honey;
2. Biochemical activity - first of all, as a source of obtaining adenosine triphosphoric, pyruvic and lactic acids in the process of anaerobic glycolysis, for fermentation (in the beer industry);
3. Pharmacological production - as one of the components added to many powders when they are insufficient, to children's syrups, various kinds of medicines, tablets, dragees, vitamins.
4. Cosmetology - for sugar depilation (shugaring);
5. Household chemicals production;
6. Medical practice - as one of the plasma replacement solutions, substances that relieve intoxication and provide parenteral nutrition (through a tube) in a very serious condition of patients. Sucrose is widely used if a patient develops

An example of the most common naturally occurring disaccharide (oligosaccharide) is sucrose(beet or cane sugar).

Oligosaccharides Are condensation products of two or more molecules of monosaccharides.

Disaccharides - these are carbohydrates, which, when heated with water in the presence of mineral acids or under the influence of enzymes, undergo hydrolysis, splitting into two molecules of monosaccharides.

Physical properties and being in nature

1. It is a colorless crystals of sweet taste, readily soluble in water.

2. The melting point of sucrose is 160 ° C.

3. When the molten sucrose solidifies, an amorphous transparent mass is formed - caramel.

4. Contained in many plants: in the sap of birch, maple, carrots, melons, as well as in sugar beets and sugar cane.

Structure and chemical properties

1. Molecular formula of sucrose - C 12 H 22 O 11

2. Sucrose has a more complex structure than glucose. The sucrose molecule consists of glucose and fructose residues linked to each other through the interaction of hemiacetal hydroxyls (1 → 2) -glycosidic bond:

3. The presence of hydroxyl groups in the sucrose molecule is easily confirmed by the reaction with metal hydroxides.

If a sucrose solution is added to copper (II) hydroxide, a bright blue solution of copper saccharate is formed (a qualitative reaction of polyhydric alcohols).

Video experience "Proof of the presence of hydroxyl groups in sucrose"

4. There is no aldehyde group in sucrose: when heated with an ammonia solution of silver (I) oxide, it does not give a "silver mirror"; when heated with copper (II) hydroxide, it does not form red copper (I) oxide.

5. Sucrose, unlike glucose, is not an aldehyde. Sucrose, while in solution, does not enter into the "silver mirror" reaction, since it is not capable of converting into an open form containing an aldehyde group. Such disaccharides are not capable of oxidizing (i.e., being reducing agents) and are called non-restoring sugars.

Video experience "Lack of the reducing capacity of sucrose"

6. Sucrose is the most important of the disaccharides.

7. It is obtained from sugar beet (it contains up to 28% sucrose by dry matter) or from sugar cane.

Reaction of sucrose with water.

An important chemical property of sucrose is the ability to undergo hydrolysis (when heated in the presence of hydrogen ions). In this case, a glucose molecule and a fructose molecule are formed from one sucrose molecule:

C 12 H 22 O 11 + H 2 O t , H 2 SO 4 → C 6 H 12 O 6 + C 6 H 12 O 6

Video experience "Acid hydrolysis of sucrose"

Among sucrose isomers having the molecular formula C 12 H 22 O 11, maltose and lactose can be isolated.

During hydrolysis, various disaccharides are split into their constituent monosaccharides due to the breaking of bonds between them ( glycosidic bonds):

Thus, the reaction of hydrolysis of disaccharides is the reverse of the process of their formation from monosaccharides.

The use of sucrose

· Food product;

· In the confectionery industry;

Obtaining artificial honey

Physical properties

Pure sucrose is a colorless crystalline substance of sweet taste, readily soluble in water.

Chemical properties

The main property of disaccharides that distinguishes them from monosaccharides is the ability to hydrolyze in an acidic environment (or under the action of enzymes in the body):

C 12 H 22 O 11 + H2O> C 6 H 12 O 6 + C 6 H 12 O 6

Sucrose glucose fructose

Glucose formed in the process of hydrolysis can be detected by the "silver mirror" reaction or by its interaction with copper (II) hydroxide.

Receiving sucrose

Sucrose C 12 H 22 O 11 (sugar) is mainly obtained from sugar beets and sugar cane. During the production of sucrose, chemical transformations do not take place, because it is already present in natural products. It is only isolated from these products as pure as possible.

The process of separating sucrose from sugar beet:

Peeled sugar beets in mechanical beet cutters are turned into thin shavings and placed in special vessels - diffusers, through which hot water is passed. As a result, almost all sucrose is washed out of the beets, but together with it, various acids, proteins and dyes pass into the solution, which must be separated from sucrose.

The solution formed in the diffusers is treated with milk of lime.

C 12 H 22 O 11 + Ca (OH) 2> C 12 H 22 O 11 2CaO H 2 O

Calcium hydroxide reacts with acids in the solution. Since the calcium salts of most organic acids are poorly soluble, they precipitate. Sucrose with calcium hydroxide forms a soluble sucrose of the alcoholate type - C 12 H 22 O 11 2CaO H 2 O

3. To decompose the formed calcium saccharate and neutralize excess calcium hydroxide, carbon monoxide (IV) is passed through their solution. As a result, calcium precipitates as carbonate:

С 12 Н 22 О 11 2CaO H 2 O + 2СО 2> С 12 Н 22 О 11 + 2CaСO 3 v 2Н 2 О

4. The solution obtained after precipitation of calcium carbonate is filtered, then evaporated in vacuum apparatus and sugar crystals are separated by centrifugation.

However, it is not possible to isolate all the sugar from the solution. A brown solution (molasses) remains, which contains up to 50% sucrose. Molasses is used to produce citric acid and some other products.

5. Separated granulated sugar usually has a yellowish color, as it contains dyes. To separate them, sucrose is redissolved in water and the resulting solution is passed through activated carbon. Then the solution is evaporated again and subjected to crystallization. (see appendix 2)

The use of sucrose

Sucrose is mainly used as a food product and in the confectionery industry. Artificial honey is obtained from it by hydrolysis.

Being in nature and the human body

Sucrose is a part of sugar beet juice (16 - 20%) and sugar cane (14 - 26%). In small quantities, it is found along with glucose in the fruits and leaves of many green plants.

Sucrose C 12 H 22 O 11, or beet sugar, cane sugar, in everyday life, just sugar - a disaccharide from the group of oligosaccharides, consisting of two monosaccharides - α-glucose and β-fructose.

Chemical properties of sucrose

An important chemical property of sucrose is the ability to undergo hydrolysis (when heated in the presence of hydrogen ions).

Since the bond between the residues of monosaccharides in sucrose is formed by both glycosidic hydroxyls, it does not have reducing properties and does not give a "silver mirror" reaction. Sucrose retains the properties of polyhydric alcohols: it forms water-soluble saccharates with metal hydroxides, in particular, with calcium hydroxide. This reaction is used to isolate and purify sucrose in sugar factories, which we'll talk about a little later.

When heating an aqueous solution of sucrose in the presence of strong acids or under the action of an enzyme invertases happens hydrolysis this disaccharide to form a mixture of equal amounts of glucose and fructose. This reaction is the opposite of the process of formation of sucrose from monosaccharides:

The resulting mixture is called invert sugar and is used for the production of caramel, for sweetening food products, for preventing the crystallization of sucrose, for producing artificial honey, for the production of polyhydric alcohols.

Attitude towards hydrolysis

The hydrolysis of sucrose can be easily traced using a polarimeter, since the sucrose solution has a right-hand rotation, and the resulting mixture D- glucose and D- fructose has a left-handed rotation due to the prevailing left-handed rotation of D-fructose. Consequently, as sucrose hydrolysis, the value of the right rotation angle gradually decreases, passes through zero, and at the end of hydrolysis, a solution containing equal amounts of glucose and fructose acquires a stable left rotation. In this regard, hydrolyzed sucrose (a mixture of glucose and fructose) is called invert sugar, and the process of hydrolysis itself is called inversion (from Latin inversia - overturning, permutation).

The structure of maltose and cellobiose. Attitude towards hydrolysis

Maltose and starch. Composition, structure and properties. Attitude towards hydrolysis

Physical properties

Maltose is easily soluble in water and has a sweet taste. The molecular weight of maltose is 342.32. The melting point of maltose is 108 (anhydrous).

Chemical properties

Maltose is a reducing sugar as it has an unsubstituted hemiacetal hydroxyl group.

When boiling maltose with dilute acid and under the action of an enzyme maltose hydrolyzed (two molecules of glucose C 6 H 12 O 6 are formed).

Starch (C 6 H 10 O 5) n polysaccharides of amylose and amylopectin, the monomer of which is alpha-glucose. The starch synthesized by different plants in chloroplasts under the action of light during photosynthesis differs somewhat in grain structure, degree of molecular polymerization, structure of polymer chains, and physicochemical properties.