Proteins are essential organic substances that are involved in building muscle tissue and are also part of hair, nails, and internal organs. They are the most abundant compound in the body (after water). Without proteins, the human body cannot exist, so you need to carefully monitor the amount of protein in your diet.

Protein is a complex structure made up of small elements (amino acids). Amino acids, in turn, are divided into substitutable and essential. They are called irreplaceable because the human body cannot produce them on its own, so they must be supplied with food. The essential amino acids include isoleucine, leucine, valine, phenylalanine, lysine, methionine, threonine, and tryptophan. For a child’s body, this list is somewhat longer. Disturbances in the metabolism of essential acids (e.g. phenylketonuria) lead to severe and sometimes irreversible consequences.

Proteins can be obtained from both animal and plant-based foods. These sources have certain advantages and disadvantages:

Animal protein is rich in B vitamins, zinc and iron;
animal sources, especially wild salmon, contain polyunsaturated fatty acids;
vegetable sources contain a large amount of fiber, which has a positive effect on the digestive system;
in addition, they contain a large amount of vitamins and useful microelements;
animal sources are high in calories and high in cholesterol, and the abuse of such products can lead to the formation of malignant tumors;
but it is quite difficult to get all the essential amino acids in sufficient quantities with the help of plant proteins.

Structure and basic functions of protein
All proteins are polymers whose monomers are amino acids. They are mainly composed of carbon, hydrogen, oxygen, and nitrogen. In the composition of most studied proteins of all living organisms, 20 amino acids were found to be involved in their construction.

In the human body, this element performs five essential functions:

Repair (being a “building material” for cells, it ensures their normal development);
Saturation with energy (the body uses it as a source of energy if it is consumed sufficiently);
Transportation of molecules (for example, hemoglobin, which saturates all tissues and organs with oxygen);
Protection (sufficient protein intake has a positive effect on the immune system);
Carrying out chemical reactions in the body (some of them are simply impossible without the participation of this element).
This organic substance is especially necessary during pregnancy. It is actively used for the development of a healthy fetal body. Also, protein should be consumed in sufficient quantities during puberty, recovery and rehabilitation after illnesses and injuries.