What role do proteins play in human life? Functions and role of proteins in the body

A person cannot live without food. Moreover, food, or better yet, proper nutrition, is the key to his health. Poor nutrition, and even systematically, you can ruin your body in a couple of years. Conversely, by eating right, you can keep your body healthy. in perfect order, which will help avoid many diseases and misfortunes. In a word, there is happiness. Well, and drink, of course.

Nutrition should be balanced. That is, the body must constantly receive so many fats, so many carbohydrates and so many proteins. The functions of all these components are different, but together they ensure the complete functioning of the body. Failure to maintain this balance leads to failures and disruption of all human life functions.

Protein plays a vital role in the functioning of our body.

It forms and shapes the tissues of our organs and muscles.

It is necessary for the synthesis of hormones.

Enzymes are formed from protein, without which the cells of the body will fail.

The nervous system also cannot function without protein, since the transmission of cellular information through the nervous system will be disrupted. We will move slowly and incorrectly and think dully. The immune system will weaken, and the slightest breath of wind will be enough for us to catch an acute respiratory infection.

Without proteins, your blood will not clot and, if you cut yourself when shaving or carelessly handling a knife, you risk bleeding out completely.

Protein normalizes the functioning of the liver and kidneys and affects the health of our skin. If we reduce our protein intake significantly, we will age catastrophically quickly.

Protein is involved in the body’s energy processes and produces 4 kilocalories of energy from 1 gram.

And in general, our DNA is protein molecules, which are the building material of the whole organism.

All this means that proteins, one way or another, are involved in most processes occurring in our body, and there is no way to do without them.

Proteins are not fats, they do not accumulate. Therefore, they must enter our body constantly and regularly. Naturally, with food that contains protein.

Where is protein found?

In milk and fish. And it is digested the fastest. Protein in meat is digested somewhat more slowly. And proteins are digested very slowly plant origin. Therefore, in order to maintain the body’s functions in order, the bulk of proteins must be of animal origin. The ratios - according to science - should be as follows: 70% of the proteins entering the body should be of animal origin (meat, milk, eggs and fish, for example) and 30% - vegetable (bread, peas, potatoes). Moreover, proteins of animal origin have an absolutely complete set of extremely needed by the body amino acids, which cannot be said about protein of plant origin. Only beans contain complete protein of plant origin. So, by going on a diet or giving up meat (and fish), we simply destroy our body, leading it to imbalance and, as a result, to death.

Protein is one of the key nutrients that must be supplied to the human body daily. To understand the role of protein in human nutrition and life, it is necessary to give an idea of what these substances are.

Proteins (proteins) are organic macromolecules that, compared to other substances, are giants in the world of molecules. Human proteins consist of similar segments (monomers), which are amino acids. There are many types of protein.

But despite different composition protein molecules, all of which consist of only 20 types of amino acids.

The importance of proteins is determined by the fact that it is with the help of proteins that all vital processes are carried out in the body.

To produce its own proteins, the human body needs the protein supplied from outside (as part of food) to be broken down into its constituent particles - monomers (amino acids). This process is carried out during digestion in the digestive system (stomach, intestines).

After protein breakdown as a result of exposure to food digestive enzymes stomach, pancreas, intestines, monomers, from which their own protein will later be built, must enter the blood through intestinal wall by suction.

And only then, from the finished material (amino acids), in accordance with the program embedded in a certain gene, will the synthesis of one or another protein be carried out, which in at the moment time is needed by the body. All these complex processes, called protein biosynthesis, occur every second in the cells of the body.

For the synthesis of complete protein, all 20 amino acids must be present in food products entering the body (animal or plant origin), especially 8, which are essential and can enter the human body only by eating protein foods.

Based on what has been said, it becomes clear important role good nutrition, ensuring normal protein synthesis.

Symptoms of protein deficiency in the body

A lack of protein, nutritional or otherwise, has a negative impact on human health (especially during periods of intense growth, development, and recovery from illness). The lack of proteins comes down to the fact that the processes of catabolism (the breakdown of one’s own protein) begin to prevail over its synthesis.

All this leads to dystrophic (and in some cases atrophic) changes in organs and tissues, dysfunction hematopoietic organs, digestive, nervous and other systems of the macroorganism.

With protein starvation or severe deficiency, the endocrine system and the synthesis of many hormones and enzymes also suffer. In addition to the obvious weight loss and loss of muscle mass, a number of common symptoms indicating a lack of protein.

The person begins to experience weakness, severe asthenia, shortness of breath on exertion, and palpitations. In a patient with a lack of protein, the absorption of basic food nutrients, vitamins, calcium, iron and other substances in the intestines is secondarily impaired, symptoms of anemia and digestive disorders are observed.

Typical symptoms of protein deficiency on the part of skin are dry skin, mucous membranes, flaccid flabby skin with reduced turgor. Insufficient protein intake impairs function reproductive organs, violated menstrual cycle and the possibility of conception and bearing a fetus. Lack of proteins leads to sharp decline immunity due to both humoral and cellular components.

Functions of proteins in the human body:

Plastic function is one of the main roles of protein, since most organs and tissues (in addition to water) of a person consist of proteins and their derivatives (proteoglycans, lipoproteins). Protein molecules constitute the so-called basis (framework of tissues and cells) of the intercellular space and all cell organelles.

Hormonal regulation. Since most hormones produced endocrine system, are protein derivatives, without proteins it is impossible hormonal regulation metabolic and other processes in the body. Hormones such as insulin (affects blood glucose levels), TSH and others are protein derivatives.
Thus, disruption of hormone formation leads to the appearance of multiple endocrine pathology person.

Enzyme function. Biological oxidation reactions and many others would proceed hundreds of thousands of times slower if it were not for enzymes and coenzymes, which are natural catalysts. Natural catalysts that provide the necessary intensity and speed of reactions are protein substances. If the production of certain enzymes is disrupted, it decreases, for example, digestive function pancreas.

Proteins are natural carriers (transporters of other macromolecules) of proteins, lipids, lipoproteins, carbohydrates, molecules with a smaller composition (vitamins, metal ions, micro- and macroelements, water, oxygen). If the synthesis of these proteins is disrupted, many diseases may occur. internal organs. Often these are hereditary diseases, for example, anemia, storage diseases.

The protective role of proteins is the production of special immunoglobulin proteins, which play one of the key roles in reactions immune defense. A decrease in immune defense contributes to frequent infectious diseases and their severe course.

A feature of protein metabolism in the human body is that, unlike fats and carbohydrates, which can be stored in reserve, proteins cannot be stored for future use. If there is a lack of protein, the body may use its own protein for its needs (and muscle mass decreases).

During fasting and a significant lack of protein, the supply of carbohydrates and fats is first consumed for energy needs. When these reserves are depleted, energy needs protein is wasted.

Normal human protein needs

A person's need for protein varies significantly and averages 70-100 grams per day. Of this total animal protein should be at least 30-60 grams. The amount of protein that should enter the body depends on large number constituent factors. Individual norm protein intake depends on gender, functional state, age, motor activity, nature of work, climate.

The need for protein also depends on whether a person is healthy or sick.

At various diseases The amount of protein you should get each day from your diet may vary. For example, high protein nutrition necessary for tuberculosis, convalescence after infectious diseases, debilitating processes, diseases accompanied long-term diarrhea. Diet with reduced level protein is prescribed for kidney diseases with severely impaired function and pathology of nitrogen metabolism and liver.

Except general content squirrel in daily ration it is necessary that the composition of the substances used protein products consisted of all the amino acids that make up the body's proteins, including essential ones. This condition is satisfied by a mixed diet, which includes both animals and vegetable proteins in the optimal combination.

Based on the amino acid content, all protein products are divided into complete and incomplete. Proteins enter the human body in the form of protein of both animal and plant origin. Meat, fish, and dairy products are more complete in amino acid composition. Vegetable protein is considered less complete in some amino acids. However, for an optimal ratio and balance of amino acids, foods must contain proteins of both animal and plant origin.

What foods contain protein?

Most protein is found in meat products. The diet uses red meat (beef, pork, lamb and other varieties), poultry meat (chicken, duck, goose). These types of meat and products prepared on their basis differ in protein composition and animal fat content.

By-products (liver, heart, lungs, kidneys) are also suppliers of protein, but it must be remembered that these products contain a lot of fat and cholesterol.

Protein from fish (sea and freshwater), as well as seafood, is very useful in human nutrition. Fish should be present in the diet healthy person at least 2-3 times a week. Different types fish differ in protein content. For example, low-protein fish such as capelin contain about 12% protein, while the protein content in tuna is about 20%. Seafood and fish are very healthy as they contain phosphorus, calcium, fat soluble vitamins, iodine.

Fish contains less connective tissue fibers, therefore it is better digested, suitable for dietary nutrition. Fish products compared to meat products that have undergone a similar process heat treatment, are lower in calories, although they create a feeling of fullness after eating them.

Milk and dairy products are a valuable source of complete protein. Dairy products are of particular importance in feeding children. Dairy products differ in protein and fat content. The most protein is in cottage cheese and cheese. Milk contains protein, but its content is this product inferior to cottage cheese, cheese.

Source of vegetable protein for humans are numerous grains, cereals and products prepared on their basis. Bread, pasta and other products are essential components of the diet. There is a lot of vegetable protein in cereals, but it is less complete in amino acid composition, so a variety of cereal products should be used in the diet, since each of them contains a slightly different set of amino acids.

Vegetable protein must be present in daily diet. A significant protein content is achieved in legumes. In addition, another property is important: legumes contain a lot dietary fiber, vitamins, little fat.

Plant seeds (sunflower seed), soybean, various types nuts (hazelnuts, walnuts, pistachios, peanuts and others) are very healthy protein products. In addition to the high content of valuable protein, these products contain significant amount vegetable fat, which contains no cholesterol. The use of nuts and seeds allows you to enrich your diet not only valuable proteins, but also polyunsaturated fatty acids, which are biological cholesterol antagonists.

Vegetables and fruits contain practically no protein, but they have a full range of vitamins that take part in many metabolic processes, including the reactions of digestion and protein synthesis.

Thus, the diet of a healthy and sick person should be balanced in all food nutrients, including protein. Varied diet is able to ensure the supply of all necessary amino acids. The amount of protein intake in a healthy and sick person in case of illness should be strictly regulated by a doctor.

Proteins in the human body are the main material for the development and growth of all cells without exception. The most diverse functions of protein in the body are not compensated by other elements, since they contain essential amino acids. The most important role of proteins in the body is that they participate in the replication of DNA and RNA molecules.

The meaning and role of proteins in the body

Life without protein is impossible. The importance of proteins for the body is that they serve as material for the construction of cells, tissues and organs, the formation of enzymes, most hormones, hemoglobin and other substances that perform functions in the body essential functions. Proteins and their role in the body is also that they are involved in protecting the body from infections, and also promotes the absorption of vitamins and minerals. Our life activity is associated with the continuous consumption and renewal of protein. To balance these processes, protein losses must be replenished daily. Unlike fats and carbohydrates, it does not accumulate and is not synthesized in the body from other nutrients, that is, you can only get protein with food.

Protein absorption by the body

The absorption of protein by the body begins in the stomach and continues in the cavity small intestine. Consequently, diseases of the pancreas and small intestine negatively affect this process. Next, you can find out how protein is absorbed in the human body and how it is consumed.

In turn, with a long-term and severe deficiency of dietary protein, the formation of digestive juices and especially enzymes is disrupted - first in the pancreas, and then in the stomach and small intestine. This leads to diarrhea not associated with intestinal infection.

Where is there a lot of protein in food?

You need to know where a lot of protein is found in order to correctly formulate the composition of your daily ration. Information on the protein content in basic foods is given in the table. From it you can get basic information about where the proteins are in the food on your table.

Table - Protein content in 100 grams of the edible part of products:

Amount of gloss, g	Food products
Very large (more than 15)	Low-fat cottage cheese, animal and poultry meat, most types of fish, seafood, egg white, soybeans, peas, beans, nuts
Large (10-15)	Cheese, full-fat cottage cheese, meat and fatty pork, whole eggs, semolina, buckwheat, oatmeal, millet, wheat flour, pasta
Moderate (5-9.9)	Rye and wheat bread, pearl barley, rice, green peas
Small (2-4.9)	Milk, kefir, cream, sour cream, ice cream, spinach, cauliflower, potatoes
Very small (0.4-1.9)	Butter, almost all vegetables, fruits, berries and mushrooms

50 grams of beef or chicken meat, cottage cheese with a fat content of 4%;
55 grams of horse mackerel, mackerel;
60 grams of cod, hake, carp;
70 grams of pork meat, fatty cottage cheese;
80 grams of whole eggs (two pieces without shells), buckwheat;
85 grams of boiled sausage;
90 grams of sausages, oatmeal, millet, pasta;
100 grams of boiled peas
100 grams of semolina and barley;
125 grams of wheat bread;
140 grams of rice;
200 grams of green peas;
350 grams of milk, sour cream, full-fat kefir;
500 grams of potatoes, white cabbage;
700 grams of carrots;
2.5 kilograms of apples, pears.

Nutritional and biological value of proteins

It is necessary to take into account not only quantity, but also quality - the biological value of proteins, which depends on the content of amino acids in it. In total, proteins can contain over 20 amino acids, but only eight of them are not formed in the body, so they must come from food. Such amino acids are called essential.

In order for food protein to be fully absorbed, amino acids must be present in it in a certain ratio. The lack of even one amino acid can prevent the full participation of all others in the construction of proteins in the body. The nutritional and biological value of proteins is calculated using special tables.

Why does the body need protein?

It has been noted that in the diet of a significant part of the population there is a deficiency of three essential amino acids: lysine, methionine, tryptophan - and a derivative of the latter - serotonin. Many people wonder why the body needs protein. large quantities if there is a process of weight loss. And this is a very dangerous mistake. Animal products are much richer in these substances. Therefore, animal proteins are not only well absorbed, but also significantly improve absorption vegetable proteins, which allows you to balance amino acid composition food during meals. You can’t exclude meat from your diet, even if you really want to lose weight.

Proteins in human nutrition: effects on the body

Biologically valuable proteins in human nutrition, characterized by a balance of amino acids and good digestibility, include proteins from eggs and dairy products, as well as meat and fish, with the exception of connective tissue. The effect of proteins on the human body largely depends on their quality and quantity supplied with food.

Less complete are plant proteins, the amino acid composition of which is not sufficiently balanced. In addition, the proteins in many plant foods are difficult to digest because they are encased in fiber and other substances that interfere with the action of digestive enzymes. This especially applies to legumes, mushrooms, nuts, and whole grain cereals. More than 90% of amino acids are absorbed from animal proteins in the small intestine, and only 70-80% from plant proteins.

How much protein does the body absorb?

Calculation of how much protein the body absorbs depends on the quality of the foods consumed and their origin. Animal proteins are absorbed 1.5 times better than proteins of plant origin.

The proteins of dairy products, eggs and fish are digested most quickly, then meat (beef proteins are faster than pork and lamb proteins), bread and cereals, and the proteins of semolina and wheat bread made from premium flour are more active.

From collagen (connective protein, cartilage and bone tissue) produce gelatin, which is used to prepare jelly-like dishes. Gelatin is incomplete in its amino acid composition, but is easily digested. In addition, it stimulates blood clotting. It is recommended to include dishes using gelatin in the diet of patients who have undergone surgery on the digestive organs. gastrointestinal bleeding, maxillofacial injuries etc.

Products containing protein

The most balanced amino acid composition of proteins in eggs, dairy products, meat and fish. These foods that contain protein are also digested faster than other proteins.

Heat treatment accelerates the digestion of proteins, which is confirmed by the example of boiled and raw eggs. Proteins are better absorbed by prolonged boiling or chopping of foods. This is especially true for plant proteins. True, excessive heat can negatively affect amino acids. Thus, the biological value of casein ( milk protein contained in cottage cheese) decreases by 50% when heated to a temperature of 200 °C. And with strong and prolonged heating of carbohydrate-rich foods, the amount of lysine available for absorption in them decreases. This explains the recommendation to soak cereals before cooking in order to reduce the cooking time of porridges.

Heat treatment and chopping foods improve protein digestion.

The above once again confirms the opinion that in order to meet the amino acid needs of the body, it is more advisable to combine different products. For example, if there is wheat bread with milk, the total amino acid composition of the protein becomes biologically more valuable than when eating bread without milk. For the same reason, combining cereals with milk or preparing milk cereal soups, milk noodles, etc. is quite justified.

Where is the most protein found?

It is also worth understanding where the most protein is found in plant-based foods. The most valuable plant proteins are found in buckwheat, legumes, potatoes, rice and rye bread.

Comparatively beneficial in this regard flour products with cottage cheese (vareniki, sochniki) or meat (dumplings, meat pies, etc.), while the combination of dough with rice and other cereals is less justified.

The biological value of proteins increases with a combination of grains, legumes and meat and dairy products. To increase the protein content of nutrition, they produce bakery products, enriched skim milk or whey, egg and milk pasta. There are also special dry concentrates with high content easily digestible proteins used to feed seriously ill patients.

However, in some cases it becomes necessary to limit protein intake, for example, in case of kidney or liver failure. For this purpose, special low-protein cereals, pasta and bakery products are used.

How much protein should a person consume per day?

Protein is an absolutely irreplaceable part of nutrition. No matter how you rearrange your diet, never significantly reduce the amount of protein: your body needs it. Next, we’ll look at how much protein a person needs to fully meet their daily needs.

At every meal, try to combine less valuable plant proteins (bread, cereal, pasta) with animal proteins (milk, cottage cheese, cheese, meat, fish, eggs).

How much protein you need per day can be calculated according to established sanitary standards. According to modern Russian standards for those not employed physical labor and sports healthy men and women aged 18-29 years, the protein requirement is on average 1 gram per 1 kilogram of normal for this person body weight. In this case, the share of animal proteins must be at least 55% of the total amount of protein. Some consider these recommendations to be too high. But there is no doubt that in the diet of people who have suffered extensive surgical interventions or serious injuries, with burn disease, bone fractures, diseases of the digestive system (such as chronic enteritis and pancreatitis, conditions after resection of the small intestine and stomach, etc.), suppurative lung diseases, active tuberculosis, malignant tumors, blood loss, taking corticosteroid and anabolic hormones, etc., as well as for patients recovering from severe infections, animal protein consumption can be increased to 55-60%. However, even in these cases, the amount of protein entering the body, as a rule, should not exceed 120-130 grams per day. How much protein you should consume depends on your lifestyle, physical activity, health status and many other factors.

Proteins in the body perform the function

Proteins in the body perform the function of recovery during chronic inflammatory processes. Protein intake is limited in case of hepatic and renal failure, gout and some other diseases. Thus, in low-protein diets prescribed for chronic renal failure, its content should be only 20-40 grams, of which 65-70% can be of animal origin. In some cases, it is even possible to temporarily exclude protein from the diet.

Lack of protein in the body

A lack of protein in the body is observed with a long-term imbalance between the intake and breakdown of protein in the body, when the breakdown process begins to predominate. Its reason lies in low protein intake from food or in the predominant consumption of low protein biological value, which are characterized by a deficiency of essential amino acids. At the same time, the diet can satisfy the body's need for energy through carbohydrates and fats. However, energy deficiency aggravates the lack of proteins: proteins begin to be spent on the body’s energy costs, and the absorption of protein supplied with food deteriorates.

In case of violation of principles rational nutrition, which may be caused by unfavorable socio-economic factors or a hobby that is not physiologically reasonable diets, the so-called nutritional protein deficiency. But more often protein deficiency is caused by various diseases. Digestion and absorption of protein are often impaired by diseases of the digestive organs, especially the pancreas and intestines. Increased protein consumption or loss is observed in active tuberculosis, infectious diseases, kidney disease, severe injuries and operations, extensive burns, malignant neoplasms, massive blood loss, etc.

For liver or kidney diseases this state Can lead to unnecessarily long low-protein diets.

A healthy adult needs to consume about 80-90 grams of protein per day, half of which should come from animal products.

Protein deficiency contributes to poor performance digestive system(especially the liver and pancreas), endocrine, hematopoietic, immune and other body systems, muscle atrophy. The body begins to absorb others less efficiently nutrients, which leads to the emergence of corresponding deficiency states, for example hypovitaminosis. Efficiency and resistance to infections decrease, recovery from various diseases slows down, in particular the healing of wounds after operations and injuries.

Excess protein in the body

Excess protein in the body is also harmful, since it causes overload of the liver and kidneys with its breakdown products. Excess animal proteins contribute to accumulation in the body uric acid, which serves as a risk factor for the development kidney stone disease and gout.

Proteins are essential chemical compounds, without which the life of the body would be impossible. Proteins make up enzymes, organ cells, and tissues. They are responsible for exchange, transport and many other processes taking place in human body. Proteins cannot be stored “in reserve”, so they must be regularly supplied to the body. They are of particular importance for people involved in sports, because proteins regulate motor functions of the body, are responsible for the condition of muscles, tendons, and bones.

Proteins are high molecular weight complex organic compounds, consisting of amino acid residues connected in a special way. Each protein has its own individual sequence of amino acids and its own location in space. It is important to understand that proteins entering the body are not absorbed by the body in an unchanged form; they are broken down into amino acids and with their help the body synthesizes its proteins.

22 amino acids take part in the formation of proteins, 13 of them can be converted into one another, 9 - phenylalanine, tryptophan, lysine, histidine, threonine, leucine, valine, isoleucine, methionine - are essential. Lack of intake into the body essential acids unacceptable, it will lead to disruption of the body’s vital functions.

It is not only the fact that protein enters the body that is important, but also what amino acids it consists of!

Protein biosynthesis is the formation in the body of the necessary proteins from amino acids by connecting them with a special type of chemical bond - a polypeptide chain. DNA stores information about the structure of proteins. The actual synthesis occurs in a special part of the cell called the ribosome. RNA transmits information from the desired gene (part of DNA) to the ribosome.

Since protein biosynthesis is multi-stage, complex, and uses information embedded in the basis of human existence - DNA, its chemical synthesis is a difficult task. Scientists have learned to obtain inhibitors of certain enzymes and hormones, but the most important scientific task is to obtain proteins using genetic engineering.

Functions of proteins in the body

The qualification presented is conditional, because often the same protein performs several functions:

Structural

Protein is part of the organelles and cytoplasm of any cell human body. Connective tissue proteins are responsible for the condition of hair, nails, skin, blood vessels, and tendons.

Enzymatic function

All enzymes are proteins.
But at the same time, there is experimental data on the existence of ribozymes, i.e. ribonucleic acid with catalytic activity.

Catalytic

Almost all 3000 enzymes known to mankind, consist of protein. Most of them are involved in the processes of breaking down food into simple components, and they are also responsible for delivering energy to cells.

Receptor function

This function is to selectively bind hormones, biologically active substances and mediators on the surface of membranes or inside cells.

Hormonal

Hormones are represented by proteins; they are responsible for regulating complex biochemical reactions of the human body.

Transport

Transport function of a special blood protein - hemoglobin. Thanks to this protein, oxygen is delivered from the lungs to the organs and tissues of the body.

Protective

Consists in the activity of proteins immune system called antibodies. It is antibodies that guard the health of the body, protecting it from bacteria, viruses, poisons, and allow blood to form a clot at the site of an open wound.

The signaling function of proteins is to transmit signals (information) between cells.

Contractive

Any human movement is complex balanced work muscles. Special proteins myosin and actin are responsible for coordinated muscle contraction.

Protein sources: animal and plant proteins

Animal protein sources:

fish;
bird;
meat;
milk;
cottage cheese (more details:);
serum;
cheeses;
eggs.

Plant based protein sources:

legumes – soybeans, beans, lentils;
nuts;
potato;
cereals – semolina, millet, pearl barley, buckwheat.

Protein standards for an adult

The human body's need for protein directly depends on its physical activity. The more we move, the faster everything happens in our body. biochemical reactions. People who exercise regularly require almost twice as much protein as the average person. A lack of protein for people involved in sports is dangerous by “drying out” the muscles and exhausting the entire body!

On average, the protein norm for an adult is calculated based on the coefficient of 1 g of protein per 1 kg of weight, i.e. approximately 80–100 g for men, 55–60 g for women. Male athletes are recommended to increase the amount of protein they consume to 170–200 g per day.

Proper protein nutrition for the body

Proper nutrition to saturate the body with protein consists of a combination of animal and plant proteins. The degree of protein absorption from food depends on its origin and the method of heat treatment.

Thus, the body absorbs approximately 80% of the total intake of animal proteins and 60% of plant proteins. Animal products contain more protein per unit mass of product than in vegetable ones. In addition, “animal” products contain all amino acids, and plant products in this regard are considered inferior.

Basic nutrition rules for better absorption squirrel:

A gentle cooking method is boiling, steaming, stewing. Frying should be excluded.
Recommended consumption more fish and birds. If you really want meat, choose beef.
Broths should be excluded from the diet; they are fatty and harmful. IN as a last resort you can prepare the first course using “secondary broth”.

Features of protein nutrition for muscle growth

For athletes who are actively gaining muscle mass, you should adhere to all the above recommendations. The majority of their diet should consist of animal proteins. They should be eaten together with plant protein products, of which soy should be given special preference.

You should also consult your doctor and consider drinking special protein drinks, the percentage of protein absorption of which is 97–98%. The specialist will individually select the drink and calculate the correct dosage. This will be a pleasant and healthy protein addition to your strength training.

Features of protein nutrition for those who want to lose weight

Those who want to lose weight should eat animal and plant protein products. It is important to separate their intake, because their absorption time is different. You should avoid fatty foods meat products, you should not overuse potatoes; you should give preference to cereals with an average protein content.

You shouldn’t go to extremes and “sit down” on protein diet. It is not suitable for everyone, because completely eliminating carbohydrates will lead to a decrease in performance and energy. It is enough to eat foods containing carbohydrates in the morning - this will give you energy throughout the day; in the afternoon, eat lean protein foods. To make up for the lack of energy in the evening, the body will begin to burn body fat, at the same time, this process will be safe for the health of the body.

Be sure to include the right and properly prepared protein foods in your diet. Protein is the main building material for the body! Together with regular training, it will help you build a beautiful athletic body!

1. Composition of protein molecules. Proteins are organic substances whose molecules include

carbon, hydrogen, oxygen and nitrogen, and sometimes sulfur and other chemicals

elements.

2. The structure of proteins. Proteins are macromolecules consisting

of tens or hundreds of amino acids. Variety of amino acids (about 20 types),

components of proteins.

3. Species specificity of proteins - differences in proteins,

included in organisms belonging to different species, determined by the number

amino acids, their diversity, sequence of compounds in molecules

squirrel. The specificity of proteins in different organisms of the same species is the reason

rejection of organs and tissues (tissue incompatibility) when transplanted from

one person to another.

4. Protein structure - complex configuration of molecules

proteins in space, supported by various chemical bonds -

ionic, hydrogen, covalent. Natural state of protein. Denaturation -

disruption of the structure of protein molecules under the influence of various factors -

heating, irradiation, chemical action. Examples of denaturation:

change in protein properties when boiling eggs, transition of protein from liquid to

hard when a spider builds its web.

5. The role of proteins in the body:

Catalytic. Proteins are catalysts that increase

the rate of chemical reactions in the cells of the body. Enzymes - biological

catalysts;

Structural. Proteins are elements of plasmatic

membranes, as well as cartilage, bones, feathers, nails, hair, all tissues and organs;

Energy. The ability of protein molecules to

oxidation with the release of energy necessary for the functioning of the body;

Contractile. Actin and myosin are proteins included in

composition of muscle fibers and ensuring their contraction due to the ability

molecules of these proteins to denaturation;

Motor. Movement of a number of single-celled organisms

organisms, as well as spermatozoa with the help of cilia and flagella, in the composition

which include proteins;

Transport. For example, hemoglobin is a protein that is part of

in the composition of red blood cells and ensuring the transfer of oxygen and carbon dioxide;

Storage. Accumulation of proteins in the body as

spare nutrients, for example in eggs, milk, plant seeds;

Protective. Antibodies, fibrinogen, thrombin - proteins,

involved in the development of immunity and blood clotting;

Regulatory. Hormones are substances that provide

along with nervous system humoral regulation of body functions. The role of the hormone

insulin in regulating blood sugar.

2. The biological significance of the reproduction of organisms. Reproduction methods.

1. Reproduction and its meaning.

Reproduction is the reproduction of similar organisms, which ensures

the existence of species for many millennia contributes to an increase

number of individuals of a species, continuity of life. Asexual, sexual and

vegetative reproduction of organisms.

2. Asexual reproduction is the most ancient method. IN

Asexuality involves one organism, while sexually most often involves

two individuals. In plants, asexual reproduction occurs with the help of a single spore.

specialized cell. Reproduction by spores of algae, mosses, horsetails,

mosses, ferns. The eruption of spores from plants, their germination and development from

them new daughter organisms under favorable conditions. The death of a huge number

disputes falling into unfavorable conditions. Low probability of occurrence

new organisms from spores, since they contain few nutrients and

the seedling absorbs them mainly from the environment.

3. Vegetative propagation - propagation of plants with

with the help of vegetative organs: aboveground or underground shoots, parts of the root,

leaf, tuber, bulb. Participation in vegetative reproduction of one organism

or parts thereof. The similarity of the daughter plant with the mother plant, since it

continues the development of the mother's body. Greater efficiency and

the spread of vegetative propagation in nature, since the daughter organism

is formed faster from a part of the mother than from a spore. Examples of vegetative

propagation: using rhizomes - lily of the valley, mint, wheatgrass, etc.; rooting

lower branches touching the soil (layers) - currants, wild grapes; mustache

Strawberries; bulbs - tulip, daffodil, crocus. Use of vegetative

propagation when growing cultivated plants: potatoes are propagated by tubers,

bulbs - onions and garlic, layering - currants and gooseberries, root

offspring - cherries, plums, cuttings - fruit trees.

4. Sexual reproduction. The essence of sexual reproduction

in the formation of reproductive cells (gametes), the fusion of the male reproductive cell

(sperm) and female (ovum) - fertilization and development of a new

daughter organism from a fertilized egg. Thanks to fertilization, obtaining

daughter organism with a more diverse set of chromosomes, which means with a more

various hereditary characteristics, as a result of which it may turn out to be

more adapted to the environment. The presence of sexual reproduction in

sexual process in plants in the process of their evolution, the appearance of the most complex

forms in seed plants.

5. Seed propagation occurs using seeds,

Vegetative propagation is also widespread). Sequence of stages

seed propagation: pollination - transfer of pollen to the stigma of the pistil, its

germination, the appearance by division of two sperm, their advancement into

ovule, then the fusion of one sperm with the egg, and the other with

secondary nucleus (in angiosperms). Formation of a seed from the ovule -

the embryo with a supply of nutrients, and from the walls of the ovary - the fruit. Seed -

the germ of a new plant, in favorable conditions it germinates at first

the seedling feeds on the nutrients from the seed, and then its roots

begin to absorb water and minerals from the soil, and the leaves begin to absorb carbon dioxide

gas from the air in sunlight. Independent life of a new plant.