Energy function of proteins: examples and description. What proteins and where does the energy function?

Our body consists of various microelements and substances. Due to their constant transformation, we can live and do our business. We do not even think about the fact that every minute of life small particles of our body constantly work, giving us benefit. Naturally, each person's task is to constantly replenish their stocks.

Substances for the life of the organism

The main substances that allow us to function fully are carbohydrates, proteins and fats. These substances are in different proportions in almost all products, but it is important to observe the balance of these elements, because otherwise health problems may begin. In this article, we will examine the functions of proteins, how they can give the body energy.

What kind of substance are proteins?

These are elements that are chains of amino acids. They have a large molecular weight, since one molecule contains several amino acids that are connected by a polypeptide bond. One unit, which is a protein, is represented by an amino acid.

This substance is an indispensable building material for the body. Of the amino acids and proteins, almost everything in the body is built: they depend on the supply of a person with oxygen, since hemoglobin is a protein. This substance helps to maintain immunity, participates in the synthesis of hormones, so necessary for the regulation of many internal processes. It is also entrusted with an energy function that is not inherent in its completeness. Without it, it is very difficult for an organism to grow and grow. But we do not need too much protein. From a large number of them are processes of fermentation and other negative effects on cells and organs.

Their main functions

Proteins perform many functions, due to this the body does not lack the regulation of any processes, the production of new cells, immune defense, and so on. Let us consider them in more detail.

1. Catalytic . Amino acids, connecting in a certain way, create enzymes that are responsible for the rate of certain reactions in the body. This is not about a dozen engaged in the catalysis of enzymes. We have about several thousand of them, and they control up to 4000 reactions. All these processes are united in one concept - metabolism. It is the proteins that determine how fast it will occur.
2. Structural - with the help of certain proteins, the shape of internal cells is preserved, in the outside we have constant forms of nails, hair and so on.
3. Protective function. It consists in the fact that the proteins that make up biological fluids, substances and cells, provide protection on the physical, chemical, immune level.
4. Regulatory - there are proteins that are not building materials of cells, do not participate in metabolism, energy function for them is not peculiar, but they are engaged in the regulation of processes in cells. They "follow" the transfer of genetic information, activity and synthesis of amino acids.
5. The transport function of proteins is that they transfer important and useful substances to the body with the blood flow or between cells.
6. Receptor - otherwise it can be called mechanochemical. Some proteins under the influence of different signals can change their length, contracting.
7. Energy function of proteins - when a protein is split, some amount of energy is released. Therefore, these substances under certain circumstances serve as its source.

In what case does the energy function of proteins arise?

Not always our nutrition is balanced so that proteins, fats and carbohydrates enter our body in exactly the amount required. Therefore, often there is a lack or excess of these or other substances.

In the case of a long absence of a sufficient amount of carbohydrates and fats, the energy function of the proteins is at the forefront. The body does not cease to consume energy, so it is the amino acid compounds that begin to supply it.

How does the release of energy occur?

Proteins are unique substances in the body. Variations of their structure can be thousands, depending on which they are distinguished by their properties. The expenditure of this substance for a long time is colossal, the same energy function of proteins leads to their splitting, therefore, their stock must be constantly replenished. In this we are helped by our own organism - there are a lot of cells that synthesize a protein, and a certain kind and property.

The release of energy occurs with the process of digesting proteins in different parts of the gastrointestinal tract. The final cleavage of amino acids occurs at the cellular level.

Conversion of proteins in the stomach

The energy function of proteins, examples of which we will consider below, begins with the cleavage of these substances in the stomach. Here the same substance comes to the rescue, only another structure - the pepsin enzyme. It is active under certain conditions (when pH is not higher than 5.0 and not lower than 2.0). By converting the secretion of the glands of the stomach, an acidic gastric juice is obtained, which has a favorable effect on the work of pepsin.

Already at this stage, the energy function of proteins begins. Pepsin is one of many enzymes that is able to break down the complex collagen protein (the main one in meat meat compounds). Connecting with water (hydrolysis), it forms intermediate products of decomposition and a small fraction of heat, which dissipates through the body, participating in energy metabolism. It can be said that the proteins that perform the energy function are not enzymes in their structure, since the latter only help this function to carry out other substances.

The involvement of the pancreas in the cleavage of proteins

The pancreas does not take in itself substances for cleavage. But she is the supplier of the necessary farmers, so without it in digesting proteins is difficult to do. It provides the digestive organs with pancreatic enzymes: proelastase, chemotripsin, trypsin, carboxypolypeptidase.

Cleavage in the intestine

Not all proteins undergo complete disintegration in the intestine, although many substances work on it. Even at the end of digestion, dipeptides and tripeptides may remain. Only some amino acids come out of this part of the digestive tract single.

Trypsin and chemotripsin help proteins to transform into polypeptides, secreting when there is a shortage of glucose in the body heat, here the energy function of proteins continues. Examples of this transformation we can observe every day, when we use various substances for food. After the decay of proteins into polypeptides, the enzyme carboxypolypeptase comes into operation - it disconnects individual amino acids from the end of the compounds formed. Proelastase digests the elastic fibers of meat products and other complex substances.

Proteins performing the energy function pass through the last stage of their cleavage in the small intestine, the duodenum. There they are exposed to villi, which contain peptidases. These substances, interacting with intestinal fluid, complete the process of cleavage of polypeptides to a small number of amino acids. Further, the process of heat distribution as energy from the breakdown of proteins occurs at the cellular level, and the final products of the cleavage of these structurally complex substances are uric acid, urea, water and carbon dioxide. Thus, we saw where the energy function of proteins is realized. It has no specific place for amino acid localization. But it is carried out from the beginning to the complete splitting of the protein.

Cell energy

The energy function in the cell is performed by such organelles as mitochondria. On the cell membrane, there are carrier molecules that drag the products of the breakdown of proteins from molecules. In this case, energy is also released, which helps synthesize ATP molecules and interacts with oxygen. Even at the cellular level, one can answer the question of which proteins perform the energy function. These are substances that are not involved in enzymatic work and construction, as in the construction of body cells involved more surviving during the cleavage of polypeptides. But they can also bring a small share of energy at the cellular level with the help of mitochondria and formed ATP molecules (a unique source of energy for all processes in the body).