Let's try to find out what importance proteins are for the human body. Carbohydrates, proteins, mineral salts, fats, vitamins, which are part of food, are necessary for a person for various internal processes.
Nutrients are an energy source that covers all expenses of a living organism. Arguing over the importance of proteins in the body, we note that they are an excellent building material necessary for the growth and reproduction of new cells.
The basic elements include carbohydrates, fats, proteins. The importance of proteins, fats, carbohydrates for the human body is obvious. Once in the digestive tract, under the influence of enzymes, they undergo physical and chemical changes, break down into simpler chemical compounds, are absorbed into the intestine, and are absorbed by the body.
Discovery story
How were proteins identified? The value for the body of these organic substances was found out only after their chemical composition was determined. In 1838, the Dutch biochemist Gerard Mulder was able to discover protein bodies, formulate the theory of protein. The researcher noted that a certain substance is present in animals and plants, it is the basis of life on the planet.
What are proteins whose importance for the body has been identified by Gerard Mulder? The word "protein" means translated from Greek - "taking first place." These biopolymers make up about half the dry weight of living organisms. In viruses, this indicator is in the range of 45–95%.
Enzyme Features
What is the importance of proteins in the human body? They are called one of the main four organic substances of living matter. By biological functions, they differ significantly. About a third of all the proteins of the human body are concentrated in the muscles, about 20% are distributed in the tendons and bones, and only 10% is in the skin.
Considering the importance of proteins in the human body, we note that the most important enzymes. Despite the fact that they are present in cells in negligible amounts, these compounds control many chemical reactions that occur in a living organism:
- muscle activity
- activity of endocrine glands;
- brain functioning;
- oxidative interactions.
A small bacterium contains hundreds of enzymes.
Protein Specificity
Analyzing the importance of proteins for living organisms, we note that proteins are an essential component of living cells. They may contain different chemical elements: hydrogen, oxygen, carbon, sulfur, nitrogen. Some protein molecules have phosphorus. Amino acids are considered their main nitrogen-containing substances.
To understand the importance of proteins in the body, we note that the properties of macromolecules are determined by the composition and sequence of amino acid residues.
Chemical composition
Between them peptide (amide) bonds are formed. In addition to polymeric long chains, residues of other organic compounds are found in proteins. On one ring of the amide bond there is an acylated or free group, the other is equipped with an amidated or free carboxyl part.
The amino part of the chain is called the M-terminus. A fragment with a carboxyl group is called the C-terminus of the peptide chain.
Between the amide fragment of one peptide group and the NH-piece of the second substance, hydrogen bonds are formed.
Those groups that are included in the composition of the radical R of amino acids are capable of interacting with each other, with neighboring molecules, creating various complex structures.
In the macromolecules of the protein there is one or more peptide chains that are interconnected by chemical cross-links. Among the most common species are disulfide bridges created by cysteine amino acid residues.
Protein Structures
What structures do proteins have? The importance for the body of this class of organic substances is explained by their ability to form several structures. The simplest structure is formed by linear embedding of amino acid fragments connected by amide (peptide) bonds. In the process of the formation of hydrogen bonds, twisting of the peptide chains in a helix is observed. The process is accompanied by the formation of a large number of hydrogen bonds, culminating in the formation of the most advantageous energy configuration.
This complex structure was first discovered by the American physicist and chemist Pauling, analyzing keratin, the main protein of hair and hair, on the basis of X-ray analysis.
He called the seen structure a-helix (a-structure).
On one of its turns there are 3.6-3.7 amino acid residues, the distance between which reaches 0.54 billionths of a meter.
Arguing over the importance of proteins for the life of an organism, we note that the stability of such a spiral is explained by hydrogen bonds formed inside the molecule. In the case of stretching of the macrostructure, it turns into a linear form.
The forces of electrostatic interaction (attraction and repulsion) prevent the formation of the correct structure. They appear between amino acid groups. Also, pyrrolidine rings affect this process, causing the peptide chain to bend in separate areas.
Then there is the orientation of individual sections of the protein macromolecule in space, accompanied by the formation of a strongly curved, spatial structure. Its stability is due to the interaction of R radicals with amino acids, accompanied by the formation of disulfide bridges, ion pairs, hydrogen bonds. It is she who characterizes the basic biological and chemical properties of protein polymers.
Classification
Depending on the spatial structure, it is customary to subdivide all proteins into two classes:
- fibrillar, acting as a structural material;
- globular, which include antibodies, enzymes, hormones.
In polypeptide chains of fibrillar proteins, the spiral form is fixed by hydrogen intramolecular bonds. In fibers of this class, peptide twisted chains are parallel to the axis, oriented to each other. Their close location allows the formation of filamentary structures. This explains the high degree of asymmetry of such biopolymers.
Fibrillar proteins are practically insoluble in water, forming solutions of high viscosity. These include proteins that are part of integumentary formations and tissues:
- myosin, a muscle tissue protein;
- collagen, which forms the basis of the skin and sedimentary tissues;
- creatine contained in the cornea, hair, feathers, wool.
A representative of this class is fibroin - a protein of natural silk. This syrupy liquid, which hardens in air into an insoluble, strong filament, is a structure that is formed using hydrogen intermolecular bonds. This is what determines the high mechanical strength of natural silk.
Globular proteins differ in the curved shape of the peptide chains. Globules have an insignificant degree of asymmetry, are characterized by high solubility in water, insignificant viscosity of the formed solutions. Among them, blood proteins can be noted:
- albumen;
- hemoglobin;
- globulin.
The separation of proteins into globular and fibrillar is very arbitrary, since there are a huge number of macromolecules with an intermediate structure.
Property dependency
Why is protein so important in the human body? Briefly, it can be noted that the variety of physical and chemical properties of protein molecules is determined by the difference in the configurations of the polypeptide chains, the conditions for the formation of the spatial structure of the macromolecule, which will affect its basic functions in the body. The amount of amino acid residues that are included in the macromolecule ranges from 51 (insulin) to 140 (myoglobin).
That is why the relative molecular weight of proteins ranges from several thousand to many millions.
Using the elementary composition, the empirical formula of the protein molecule, hemoglobin of blood, was established. Hormones and enzymes have a less complex structure. Thus, the molecular weight of insulin is 6500, and that of the influenza virus is 320.000.000.
Features of polypeptide molecules
It is customary to include substances of protein nature, which contain amino acid residues joined by peptide bonds. They have a lower value of relative molecular weight, a degree of spatial organization than protein.
When dissolved in water, a molecularly dispersed system is obtained, which is a solution of a high molecular weight compound. Part of the compounds is isolated in the form of crystals: hemoglobin, blood, chicken egg protein.
Great value for the body of proteins, fats, carbohydrates.
Polypeptides in the digestive processes are digested to various amino acids. They are highly soluble in water, therefore, they enter through the bloodstream to all cells and tissues of the body.
In part, they are spent on the synthesis of proteins specific to each organism, the synthesis of hormones, enzymes, and other biologically significant substances. The remaining amino acids are energy material.
Functions
The following functions of protein molecules are distinguished:
- catalytic (enzymes accelerate hydrolysis);
- regulatory (hormones);
- protective (thrombin, antibodies);
- transport (ceruloplasmin, hemoglobin).
Protein metabolism occupies a special place. The importance of protein metabolism in the body cannot be described in one sentence. They are the main components of animal feed, human food. Metabolism is based on the continuously ongoing processes of their transformations, it depends on the amino acids that make up their composition.
The importance of vitamins
Arguing over the importance of proteins, fats, carbohydrates for the body, let's talk about a group of compounds called vitamins.
Each of them has a certain function, indispensable for a living organism.
Vitamin E protects cells from the negative effects of free radicals. It slows down the aging process, improves the appearance of nails, hair, skin. This compound is a means of preventing blood clots in blood vessels.
Vitamin A controls the growth in children and adolescents, it optimizes the metabolic processes in the adult body, maintains the normal state of the mucous membranes.
Vitamin B 12 affects the digestive processes, takes part in the metabolism. It significantly reduces the risk of anemia, promotes the formation of stamina, is responsible for the tone of the body, systematizes brain processes.
Vitamin D is a means of preventing rickets in children. It improves the absorption of calcium, has a positive effect on the state of the blood, stimulates cardiac activity, improves the thyroid gland, improves immunity.
Vitamin B6 optimizes the process of amino acid production, protein digestion. This substance stimulates the production of hemoglobin and red blood cells.
B1 stimulates metabolic processes in a living organism. This vitamin strengthens the nervous system, optimizes the activity of the cardiovascular system.
PP regulates the activity of the gastrointestinal tract, liver, pancreas. It is he who controls the production of gastric juice.
Vitamin H provides a normal level of beneficial microflora in the intestine; it positively affects the condition of nails, hair, and skin integuments.
Ascorbic acid is an essential element in the synthesis of enzymes. It supports the elasticity of cartilage and connective tissue, promotes the absorption of iron by the body.
Vitamin K is responsible for the development of bone tissue, blood coagulation. Lack of any of these substances negatively affects the life of the body, leads to a weakening of immunity, a decrease in human performance.
Lipids
We continue the discussion about the importance of proteins, fats, carbohydrates, and vitamins for the body. The most “hated” part, according to the representatives of the female sex, are fats. But without these organic compounds, the body will not be able to fully function, a person will turn into a withered skeleton, deprived of strength.
Lipids are compounds that are composed of fatty acids and glycerol (polyhydric alcohol). They are a source of energy, accompany the process of assimilation of vitamins E, D, A.
It is with these organic compounds that a person receives essential fatty acids: linolenic, linoleic, arachidonic.
Without fats, the transmission of nerve impulses is impossible, since they are part of the cell membranes, affect their permeability.
For example, more than half the brain is made up of fats that enter the body with food.
Scientists have concluded that for full-fledged activity an adult needs 3.5-4 liters of fat. Among its main functions, we note:
- body temperature control;
- accumulation of nutrients and energy;
- protection against mechanical damage;
- filtering substances that enter the body;
- the production of hormones responsible for the normal functioning of the body.
In addition, fats help maintain external beauty, give the skin elasticity, natural shine.
It is customary to subdivide them by origin into animal and plant species. The first group includes: lard, sausages, fatty meat. When oxidized, they are partially converted into energy, the rest accumulate under the skin. With an excess of such acids, a significant amount of cholesterol appears, atherosclerosis develops. The body metabolizes them slowly.
Vegetable fats have a significant amount of unsaturated organic acids, which are quickly broken down in the body. For example, fatty acids Omega 3, Omega 6 are necessary for a person to fully function the cardiovascular system, to prevent the production of cholesterol.
The value of fats for the body is comparable to proteins and carbohydrates. Every day, an adult should consume at least 100 grams of fat.
Conclusion
With the right diet, you can count on supplying the body with all the necessary components without worrying about gaining extra weight.
Currently, many people are trying to monitor their health: physical activity, nutrition, skin condition. In order to be a successful, wealthy, sought after person, it is important to control the amount of vitamins, proteins, fats, carbohydrates consumed by the body. All these organic compounds perform important functions, so you can not replace one with another.