What role do proteins play in the life of the body. Encyclopedia of Vegetarianism

The main thing is not the design of the house, but what it is built from! If the material is strong, moisture resistant, then the house will serve you for a long time and will not bring much trouble, but if the material is of poor quality, expect a lot of breakdowns and lengthy repairs. Proteins are the main building material for the human body. Biological role protein is invaluable. Each cell of the human body consists of them by 50%. They are the building blocks of bones, skin and hair. They won't start without them. biochemical reactions, hormones and enzymes are not produced.

In turn, proteins in the body are made up of amino acids. Amino acids are arranged one after another, like beads in a necklace. In this case, a long chain is formed, in which the amino acids are in strict sequence. Their location determines the biological and chemical properties of the protein. Amino acids are divided into two groups: essential and non-essential. Essential amino acids are not produced in the human body. They must in without fail enter the body from food. Non-essential amino acids are made using other amino acids. To understand the importance of proteins for the body, consider what functions they perform.

Functions of proteins in the body

Proteins protect against disease. They fight viruses, fungi, bacteria and toxins. They are involved in blood clotting, protecting a person from excessive blood loss.

Regulate hormonal background. Hormones in our body are made up of proteins. If your glands get raw Low quality, it affects their functioning.

Help to digest food. Enzymes in the body that are involved in digestion are proteins. The popular expression “I have a stomach” only indicates the absence of the necessary building material in the body.

Saturate the body with oxygen. In the blood, hemoglobin, which is made up of protein and iron, is responsible for transporting oxygen. Even if you eat the product with great content iron, but do not replenish protein, hemoglobin will not increase. Oxygen, in turn, is a powerful blood purifier and acts as an oxidizer, it burns toxins to ensure their removal from the cell. Hemoglobin also delivers oxygen to the brain, keeping your thoughts fresh.

Proteins help increase muscle mass. These nanometer particles in the body form the basis of muscle tissue, speed up metabolism at rest, and also block the feeling of hunger.

They protect you from premature aging. Keratin and collagen are protein compounds that make up the epidermis and are responsible for its strength, firmness, smoothness and elasticity.

The role of proteins in the human body is invaluable. Their insufficient amount leads to disturbances in the functioning of the body. The liver, pancreas and endocrine system are especially affected. In addition, the metabolism and absorption of vitamins are disturbed, muscle atrophy is observed, memory deteriorates and chronic fatigue appears. This is especially detrimental to the development of the child, which is manifested by slow growth and bone fragility. You may also experience the following symptoms:

drastic weight loss
hair loss and fading,
paleness, dryness and flaking of the skin,
edema,
uneven nails,
weakness and apathy
slow wound healing.

But too much protein can also be harmful. He is not able to linger in the body. Excess protein is converted by the liver into white crystals called urea, which the kidneys have to remove. The amount of protein that exceeds the norm forms an acidic environment of the body, which leads to an increase in the loss of calcium. But in human life, an excess of proteins in the body is very rare, more often there is a shortage of them.

Consumption rate

Depending on the composition of amino acids in proteins, complete and incomplete proteins are distinguished. Until recently, it was believed that incomplete proteins are found in plant foods such as beans, bread, nuts. And only meat, fish, dairy products, as well as eggs were considered. But recent studies refute this fact, the fact is that by supplementing the proteins of one plant product with the proteins of another, we can easily obtain the necessary set of amino acids.

Dietary proteins are not ideal for digestion, which means that not all of the protein is used for their synthesis. Therefore, nutritionists recommend combining some products with each other. For example, the combination of whole grains with legumes contributes more. Heat treatment also contributes better assimilation squirrel. However, during the preparation of vegetable protein, the temperature should be low.

The role of proteins in the human body is fully realized if a certain rate of their consumption is observed. For diet healthy person 1 g of protein per 1 kg of weight is needed. For children, pregnant women and people actively involved in sports, this number increases to 1.5-2 grams. Each main meal should have 30% of the protein from the daily value and 5% for a snack.

100 g of soy - 39 g of protein,
100 g pumpkin seeds- 30 g,
100 g potatoes - 2 g,
100 g - 5 g.

It is also important to follow the rules for their preparation. Do not cook the product at very high temperature, it is better to extend this process. Legumes should be soaked for a while, and only then boiled. If you follow certain cooking rules, proteins will be absorbed by the body better.

Vegetable protein and animal protein

Animal protein is found in animal products such as meat, fish, eggs and dairy products. Often a person prefers these products, but they are fraught with danger. A large adverse effect on the body, so it is worth diversifying your daily diet with food containing vegetable protein.

It is represented by products of four groups:

legumes(peas, chickpeas, lentils, beans, soybeans and others),
grain crops (wheat, barley, barley, millet, buckwheat),
nuts and seeds (almonds, peanuts, cashews, sunflower and pumpkin seeds),
vegetables (cabbage, garlic, potatoes, beets, spinach).

Medicine knows that people who prefer animals are less likely to get sick in their lives. oncological diseases less prone to obesity and diabetes. Plant-based proteins keep you full longer, which helps you avoid overeating throughout the day.

Rules for eating protein foods

Start your day with a protein breakfast. This will provide you with a feeling of satiety, and you will not get hungry soon. Known fact: in the first half of the day, proteins are absorbed better.

Combine protein foods. Dilute your diet with plant-based protein foods.

Split your protein intake throughout the day. It will be difficult for the body to absorb all daily allowance squirrel at a time.

If you are driving active image life, a serving of protein 30 minutes after a workout will help you get in perfect shape.

Determine your protein intake and stick to it strictly. The amount of protein above the norm can cause poisoning.

Combine products correctly. For example, spirulina algae is well compatible with vegetables that are rich in starch. Vegetables and greens will be an excellent addition. Legumes are ideally combined with greens and cereals.

Prepare protein foods minimum temperature, cook them longer, and pre-soak the legumes.

Protein needs a lot of water to digest. Use it enough A: It is generally recommended to drink eight glasses of water a day.

Keep the proportion of proteins in your diet with fats and carbohydrates, follow the above rules. Then you will feel a surge of strength and health, as well as destroy excess weight. Good luck on your path to a healthy life!

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

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

elements.

2. The structure of proteins. Proteins are macromolecules composed of

from tens, hundreds of amino acids. Variety of amino acids (about 20 kinds),

included in proteins.

3. The species specificity of proteins is the difference between proteins,

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

amino acids, their diversity, the 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) during their transplantation from

one person to another.

4. The structure of proteins is a complex configuration of molecules

proteins in space, supported by a variety of chemical bonds -

ionic, hydrogen, covalent. The natural state of the protein. Denaturation -

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

heating, irradiation, the action of chemicals. Examples of denaturation:

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

solid when building a spider 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 the plasma

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 the energy necessary for the life of the body;

Contractile. Actin and myosin are proteins that make up

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

molecules of these proteins to denaturation;

Motor. Movement of a number of unicellular

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

in the composition of erythrocytes and providing the transfer of oxygen and carbon dioxide;

Reserve. Accumulation of proteins in the body

reserve nutrients, such as 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 the nervous system humoral regulation of body functions. The role of the hormone

insulin in the regulation of blood sugar.

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

1. Reproduction and its importance.

Reproduction is the reproduction of similar organisms, which provides

the existence of species for many millennia, contributes to an increase

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

vegetative reproduction of organisms.

2. Asexual reproduction is the most ancient method. IN

asexually involves one organism, while sexually most often involves

two individuals. Plants reproduce asexually by means of a spore

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

club mosses, ferns. Eruption of spores from plants, their germination and development from

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

disputes that fall into unfavorable conditions. Low probability of occurrence

new organisms from spores because 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,

leaves, tubers, bulbs. Participation in vegetative reproduction of one organism

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

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

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

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

reproduction: with the help of rhizomes - lily of the valley, mint, wheatgrass, etc .; rooting

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

Strawberry; bulbs - tulip, narcissus, crocus. The use of vegetative

reproduction in the cultivation of 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 germ cells (gametes), the fusion of the male germ cell

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

daughter organism from a fertilized egg. Through fertilization

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

a variety of hereditary traits, as a result of which it may be

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

sexual process in plants in the course of their evolution, the emergence of the most complex

forms in seed plants.

5. Seed propagation occurs with the help of seeds,

vegetative propagation is also widespread). Sequence of steps

seed reproduction: pollination - the transfer of pollen on the stigma of the pistil, its

germination, the appearance by division of two spermatozoa, their advancement in

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

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

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

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

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

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

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

Proteins, like vitamins and other beneficial substances, are an integral part of the healthy functioning of our body.

Most of our diseases are associated with malnutrition, in particular with a high intake of proteins. Experts never tire of repeating that our body needs a balanced diet. The exclusion of some product from our diet can also lead to trace elements, which in turn leads to disruption of the body.

Most often, people underestimate the role of proper nutrition in the functioning of our body. According to a sociological survey, it became known that 50% (of those surveyed) do nothing to maintain their health.

Proteins play an important role in the formation of tissues (organs, muscles, etc.), they are needed in the synthesis of hormones, and are also necessary for the formation of enzymes. The transfer of the necessary information from one cell to another through the nervous system is also associated with proteins. Proteins help in the process of blood coagulation, DNA represents protein molecules, and proteins are also involved in the energy processes of the body (4 kcal of energy is obtained from 1 g of protein).

From this we can conclude that proteins are involved (directly or indirectly) in most of the processes that take place in our body. If there is a lack of proteins in the body, then all of the above processes will suffer.

The process of protein digestion comes from different speed. Proteins obtained by the body from fish meat or dairy products are digested most quickly, followed by proteins obtained from meat products. Proteins are digested more slowly plant origin.

What proteins should be preferred? Nutritionists say that in order to maintain normal functioning organism in the menu must be included 30% vegetable proteins and 70% animal proteins. These data should only be changed if you have any pathology: for example, when renal pathology preference should be given to proteins of plant origin.

An important role in required quantity proteins plays and the surrounding climate. So, for example, vegetarians from Asia are quite healthy with daily use 30-40g of proteins, while the Eskimos consume 200-300g of proteins.

In my own way chemical composition proteins can be divided into complete and incomplete. To determine the usefulness of proteins, the presence of essential amino acids is considered, since it can synthesize all the rest itself. Complete proteins in their composition have all the essential amino acids in the amount that the body needs.

Animal proteins have a complete set of essential amino acids (meat, fish, eggs and milk).

Proteins of vegetable origin are considered incomplete, with the exception of legumes. Beans contain the same amount of protein as animal products.

For the full functioning of the body proteins of animal origin are necessary, as they are absorbed by 94-97%. However, this does not mean that you should not include vegetable proteins in your menu. For the full growth and development of the body, a balance between animal and vegetable proteins is necessary.

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

Proteins (proteins) are organic macromolecules, which, in comparison with other substances, are giants in the world of molecules. Human proteins consist of segments of the same type (monomers), which are amino acids. There are many varieties of protein.

But despite different composition protein molecules, they all 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 in the body that all life processes are carried out.

For the production of its own proteins, the human body needs the protein that comes from outside (as part of food) to break down into its constituent particles - monomers (amino acids). This process is carried out in the process of digestion in 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 is then built, must enter the blood through intestinal wall by absorption.

And only then, from the finished material (amino acids), in accordance with the program laid down in a certain gene, will the synthesis of one or another protein, which the body needs at a given moment in time, be produced. All these complex processes, which are called protein biosynthesis, take place every second in the cells of the body.

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

Based on the foregoing, it becomes clear the important role good nutrition for normal protein synthesis.

Symptoms of protein deficiency in the body

The lack of protein of alimentary or other nature negatively affects human health (especially during periods of intensive growth, development, recovery after 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 a pronounced deficiency, the endocrine system also suffers, the synthesis of many hormones and enzymes. In addition to the obvious weight loss and loss of muscle mass, there are a number of common symptoms that indicate a lack of protein.

A person begins to experience weakness, severe asthenia, shortness of breath on exertion, and palpitations. In a patient with a lack of protein, the absorption in the intestines of the main food nutrients, vitamins, calcium, iron and other substances is already disturbed for the second time, symptoms of anemia and digestive disorders are observed.

Typical symptoms with a lack of proteins from the side skin are dry skin, mucous membranes, flaccid flabby skin with reduced turgor. With a lack of protein intake, the function of the reproductive organs is disrupted, menstrual cycle and the possibility of conception, bearing the fetus. Protein deficiency 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 of the human organs and tissues (in addition to water) consist of proteins and their derivatives (proteoglycans, lipoproteins). Protein molecules make up the so-called basis (backbone of tissues and cells) of the intercellular space and all cell organelles.

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

enzymatic 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. Protein substances are natural catalysts that provide the necessary intensity and speed of reactions. In violation of the production of certain enzymes, it decreases, for example, digestive function pancreas.

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

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

A feature of protein metabolism in the human body is that, unlike fats and carbohydrates that can be stored in reserve, proteins cannot be stored for future use. With a lack of protein, the body's own protein can be consumed for the needs of the body (while muscle mass decreases).

With starvation and a significant lack of protein, the supply of carbohydrates and fats is first consumed for energy needs. With the depletion of these reserves, protein is spent on energy needs.

Normal human need for protein

The human need for proteins varies greatly 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 a large number of constituent factors. Individual norm protein intake depends on sex, functional state, age, motor activity, nature of work, climate.

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

In various diseases, the amount of protein that should be supplied daily with food may vary. For example, high protein nutrition necessary for tuberculosis, convalescence after infectious diseases, debilitating processes, diseases accompanied by prolonged diarrhea. Diet with reduced level protein is prescribed for diseases of the kidneys with a sharply impaired function and pathology of nitrogen metabolism, liver.

Except general content protein in the daily diet, it is necessary that the composition of the consumed protein products consists of all the amino acids that make up the proteins of the body, including essential ones. This condition is satisfied by a mixed diet, which includes both animal and vegetable proteins in an optimal combination.

According to the content of amino acids, all protein products are divided into complete and inferior. Proteins enter the human body in the form of proteins of both animal and vegetable origin. More complete in amino acid composition are meat, fish, dairy products. Vegetable protein is considered less complete for some amino acids. Nevertheless, for the optimal ratio and balance of amino acids, proteins of both animal and vegetable origin must be present in food.

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 protein suppliers, but it must be remembered that these products contain a lot of fat and cholesterol.

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

Fish contains less connective tissue fibers, so it is better digested, suitable for diet food. Compared to meat products that have undergone a similar heat treatment, fish products are less high-calorie, although they create a feeling of satiety after eating them.

Milk and dairy products are a valuable source of complete protein. Dairy products are of particular importance in the organization of nutrition for children. Dairy products differ in protein and fat content. Most protein in cottage cheese and cheese. Milk contains protein, but its content in this product inferior to cottage cheese, cheese.

Source of vegetable protein for a person are numerous cereals, cereals and products prepared on their basis. Bread, pasta and other products are essential components in the diet. There is a lot of vegetable protein in cereals, but it is less complete in terms of 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 of dietary fiber, vitamins, and little fat.

Plant seeds (sunflower seed), soy, different kinds nuts (hazelnuts, walnuts, pistachios, peanuts and others) are very useful protein foods. Apart from high content valuable protein these products contain significant amount vegetable fat that does not contain cholesterol. The use of nuts and seeds allows you to enrich the 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 the whole set of vitamins that take part in many metabolic processes, including digestion and protein synthesis reactions.

Thus, the diet of a healthy and sick person should be balanced for all food nutrients, including protein. Diverse food able to provide all the necessary amino acids. The amount of incoming protein in a healthy and sick person in case of diseases should be strictly regulated by a doctor.