Carbohydrates: norm, types, carbohydrate metabolism, biological significance

Carbohydrates, or as they are called - saccharides, this is the unifying name for organic compounds, which includes carbon itself, as well as hydrogen and oxygen compounds.

Saccharides are rightly considered to be the main source of energy resources of the body - they supply energy almost instantaneously, but do not retain it, unlike fats that control the supply of more than 80% of energy resources, and proteins that store energy in skeletal muscles.

Due to their specific diversity, saccharides can perform a lot of functions in the human body, their biological role in metabolic processes is extremely important.

[1], [2], [3]

Carbohydrates, role and biological significance

• Saccharides participate in the construction of body cells.
• Carbohydrates, being oxidized, supply energy to the body. Oxidation of only one gram of carbohydrates releases 4 kilocalories.
• Saccharides can act as a defense of cell walls.
• Carbohydrate compounds are involved in the regulation of osmosis (osmotic pressure).
• Carbohydrates enter the structure of some monosaccharides (ribose, pentose), participating in the construction of adenosine triphosphate (ATP).
• Oligosaccharides have a receptor property (perceiver).

[4], [5], [6], [7]

How do carbohydrates work?

1. All saccharides are the best "fuel" and source of energy for normal, active functioning of the body. Perhaps for the brain, more precisely for its nutrition and life, there is no more important component than carbohydrates. 
2. The source of carbohydrates can be sugar, honey, corn syrup, some types of vegetables, dairy products, flour products, beans. 
3. In the body, the transformation of saccharides into the main type of "fuel" - glucose. There are carbohydrates, which, splitting, turn into glucose swiftly, there are also those that absorb a little longer, so the flow of glucose into the blood will be gradual. 
4. Glucose penetrates into cells with the help of insulin, some saccharides are deposited in the liver as a reserve for possible active actions. If the reserve rate is exceeded, or this reserve is not used (a sedentary lifestyle), the fat tissue begins to form.

Types of carbohydrates

Carbohydrates are classified into the following categories: 

• Simple 
  • Monosaccharides are galactose, fructose, glucose 
  • Disaccharides are lactose and sucrose 
• Complex (polysaccharides) - fiber (fibrous saccharides), starch and glycogen.

Simple saccharides are very quickly absorbed and soluble in water, it is all the usual sugar and other products in which it is.

Among carbohydrates "an honorable" place is taken by glucose, which is part of almost all types of fruits and berries. Glucose is a monosaccharide, which, when digested, stimulates the production of glycogen. Glucose is a saccharide necessary for the body, which supplies the muscles, the brain, maintains the sugar balance in the bloodstream and controls the level of glycogen in the liver.

Fructose, in fact, is very similar in functions and properties to glucose, and is considered to be easily digestible sugar, which differs from glucose only in that it is quickly excreted and does not have time to fully digest by the body. Saturation of the liver with fructose is not dangerous, moreover fructose is easier to transform into glycogen than glucose. The excess of fructose in the blood can not be in principle, because it quickly leaves the blood.

Sucrose is the kind of carbohydrate that promotes fatty clusters, provoking the transformation into lipids of all nutrients, even protein. In fact, sucrose is the progenitor of fructose and glucose, which "give birth" when hydrolyzing sucrose.

The amount of sucrose, to some extent, is the index of fat metabolism in the body. Also, excess sugar will sooner or later affect the composition of blood serum and the state of the intestinal microflora. The microflora of the intestine is initially populated with microorganisms, the amount that is regulated by an acid-base and enzymatic process. Exceeding the level of sucrose leads to a rapid multiplication of microbacteria, which is a risk of dysbiosis and other dysfunctions on the part of the digestive tract.

Galactose is a rare monosaccharide, which does not occur as an independent component in food. Galactose is produced only by cleavage, dissimilation of lactose, a dairy carbohydrate.

Carbohydrate metabolism

Carbohydrates are able to deliver energy to the body quickly and efficiently, and in such a way that the essential amino acids from whose remains proteins are created are not used. If a person receives a sufficient amount of saccharides with food, his protein-carbohydrate metabolism is in a normal state.

If saccharides do not come from outside, the body begins to form them from glycerol and its own organic acids (amino acids), using protein and fat stores, ketosis develops - oxidation of blood, up to persistent metabolic disorders.

If carbohydrates in the form of sugars enter the body in excessively large amounts, they do not have time to split into glycogenes and transform into triglycerides, provoking the accumulation of fatty layer. It is also important for the normal carbohydrate metabolism species diversity of saccharides, special attention should be paid to the balance of sugars, glycogen and starch (slowly absorbed carbohydrates).

The metabolism of saccharides is of three types: 

1. Synthesis of glycogen in the liver and muscles from glucose - glycogenesis 
2. Synthesis of glycogen from proteins and fatty acids - glycoeogenesis 
3. Splitting of saccharides (glucose and others), energy production - glycolysis

The metabolism of carbohydrates directly depends on the amount of glucose in the blood. The level of glucose in turn depends on the diet, since glucose enters the body only with food. The minimum sugar content in the blood is usually in the morning, respectively, and low carbohydrate metabolism. While a person sleeps, the intake of sugar is regulated by glycogen stores (glycolysis and glyco-neogenesis).

[8], [9], [10]

Norms of carbohydrates

The need for saccharides depends on many factors - sex, age, the nature of the work, the state of health. The average daily rate for women is 300-350 grams, for men it is higher - 400-450 grams. Easily assimilated carbohydrates should be excluded from the diet for diabetes, exacerbation of coronary heart disease, minimize with atherosclerosis, allergies, hypothyroidism and gallbladder diseases.

Carbohydrates in the form of fiber, despite their popularity, should also meet the norm - no more than 30-35 grams per day, both for men and women. Especially cautious with fiber should be patients with exacerbation of gastrointestinal diseases. Without limitations, cellulose can be used for diabetes, obesity, constipation.

The proportion of starchy saccharides, glycogen in the diet should be at least 80% of the total volume of food, because these carbohydrates are split in the digestive tract gradually and do not provoke the production of fats.

So-called "harmful" saccharides are found in sugar, in all flour and pasta, except for products made from flour of coarse varieties (or with the addition of bran). More useful and energy-intensive carbohydrates are in dried fruits, honey, milk and dairy products, fruits and berries.