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 and moisture-resistant, then the house will serve you for a long time and will not cause 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 proteins are inestimable. Every cell of the human body consists of 50% of them. They are the structural elements of bones, skin and hair. They won't launch 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 is determined by 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 mandatory enter the body from food. Nonessential amino acids are made using other amino acids. To understand the importance of proteins for the body, let's consider what functions they perform.

Functions of proteins in the body

Proteins protect against disease. They fight viruses, fungi, bacteria and toxins. They participate 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, this affects their functioning.

Helps digest food. Enzymes in the body that are involved in digestion are proteins. The popular expression “I have a stomachache” only indicates the lack of the necessary building material in the body.

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

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

They are the ones who 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. An insufficient amount of them 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 is disrupted, muscle atrophy is observed, memory deteriorates and chronic fatigue appears. This has a particularly detrimental effect on the development of the child, which is manifested by slower growth and brittle bones. The following symptoms may also occur:

sudden weight loss,
hair loss and dullness,
pale, dry and flaky skin,
swelling,
unevenness on the nails,
weakness and apathy,
slow healing of wounds.

But too much protein can also cause harm. It is not able to stay in the body. The excess protein is converted by the liver into white crystals called urea, which the kidneys are forced to remove. An excess amount of protein creates an acidic environment in the body, which leads to increased calcium loss. But in human life it is very rare to find an excess of proteins in the body; more often there is a lack 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 were found in plant foods such as beans, bread, and nuts. And only meat, fish, dairy products, and 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.

Proteins that come from food are not ideal for absorption, which means that not all the protein is used for their synthesis. Therefore, nutritionists recommend combining some foods with each other. For example, a combination of whole grains and legumes is more beneficial. Heat treatment also contributes better absorption squirrel. However, the temperature should be low when cooking vegetable protein.

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

100 g soy – 39 g 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 temperatures high temperature, better prolong this process. Legumes should be soaked for a while and only then boiled. If you follow certain cooking rules, proteins will be better absorbed by the body.

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. Too much has an unfavorable effect on the body, so it’s worth diversifying your daily diet with foods containing plant protein.

It is represented by products of four groups:

legumes(peas, chickpeas, lentils, beans, soybeans and others),
grain crops (wheat, barley, pearl 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 to animals are less likely to get sick in their lives. oncological diseases, are less prone to obesity and diabetes mellitus. Plant proteins keep you full longer, which helps you avoid overeating throughout the day.

Rules for eating protein foods

Start your day with a protein-rich breakfast. This will make you feel full and you won't be hungry any time 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.

Divide your protein portions throughout the day. It will be difficult for the body to absorb all daily norm squirrel at a time.

If you are driving active image life, a portion of protein 30 minutes after training will help you get into ideal shape.

Determine your protein intake and stick to it strictly. An amount of protein higher than normal can cause poisoning.

Combine foods correctly. For example, spirulina algae is well compatible with vegetables that are rich in starch. Vegetables and herbs will be an excellent addition. Legumes go perfectly with herbs and cereals.

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

Protein requires a lot of water to digest. Consume it sufficient quantity: As a general rule, it is recommended to drink eight glasses of water per day.

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

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 life 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

reserve 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 the 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

using vegetative organs: above-ground 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

reproduction: 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.

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

Most of our diseases are associated with poor nutrition, in particular with high consumption of proteins. Experts never tire of repeating that our body needs a balanced diet. Excluding some product from our diet can lead to microelements, 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 for the synthesis of hormones, and are also necessary for the formation of enzymes. The transmission of necessary information from one cell to another through the nervous system is also associated with proteins. Proteins help in the process of blood clotting, DNA represents protein molecules, and proteins also participate in the body’s energy processes (1g of protein produces 4 kcal of energy).

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

Process of protein digestion happens with at different speeds. Proteins obtained by the body from fish or dairy products are digested the fastest, followed by proteins obtained from meat products. Proteins are digested more slowly plant origin.

What proteins should you give preference to? Nutritionists say that to maintain normal functioning organism in the menu must be included 30% plant 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 The surrounding climate also plays a role in protein factors. For example, vegetarians from Asia are quite healthy when daily use 30-40g of protein, while Eskimos consume 200-300g of protein.

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 contain all the essential amino acids in the quantities needed by the body.

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

Plant based proteins are considered incomplete, with the exception of legumes. Beans contain the same amount of proteins 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 plant proteins in your menu. For full growth and development of the body, a balance between animal and plant proteins is necessary.

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 component particles - monomers (amino acids). This process occurs during the digestion process. 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, which is needed by the body at a given moment in time, be carried out. 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 the above, it becomes clear the 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 appear that indicate 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. With a lack of protein intake, the function of the reproductive organs is impaired, 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 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, 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 a key role in immune defense reactions. 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, protein is spent on energy needs.

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 account for 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 gender, functional state, age, motor activity, nature of work, climate.

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

For various diseases, the amount of protein that should be supplied daily from 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 kidney diseases with severely impaired function and pathology of nitrogen metabolism and liver.

Except general content protein in the daily diet, it is necessary that the composition of the protein products consumed consist 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 animal and plant proteins in an 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 of a healthy person at least 2-3 times a week. Different types of 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 similar 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, one more property is important: legumes contain a lot of dietary fiber, vitamins, and little fat.

Plant seeds (sunflower seed), soybean, different kinds nuts (hazelnuts, walnuts, pistachios, peanuts and others) are very healthy protein products. Besides high content These products contain valuable protein 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 antagonists of cholesterol.

Vegetables and fruits contain virtually no protein, but 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 can 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.