Collagen constitutes 30% of the total mass of human proteins and  is responsible for:

skin firmness                                      skin moisturisation
skin suppleness                                  constant renewal of skin cells

It takes part in vital functions of nearly all systems, organs and tissues . Collagen is the main protein of connective tissue. It has great tensile strength and is the main component of ligaments, tendons, cartilage, bone and teeth. Along with soft keratin, it is responsible for skin strength and elasticity. With age the human body loses the ability to rebuild collagen . Especially after constant damage i.e. physical activity, competitive sports. Also with autoimmunity diseases  ( joint degeneracy ). It is responsible for skin elasticity and its degradation leads to wrinkles. Collagen deficiency also causes age changes in the body such as colour changes, cellulite, skin dryness, dull lifeless hair and nails. Lack of collagen that causes disorders within the immune system are the most damaging for health. This is because collagen has a very important defensive function . It limits absorption and spreading of pathogenic substances, environmental toxins, micro - organisms and cancerous cells. Collagen is a simple protein built only from amino acids, belonging to fibrous proteins, precisely to fibrin proteins. It is built from small protein parts in the shape of spiral chains, which consist of 19 amino acids.

proline                                                     glicine
hydroxyproline                                           hydroxylisine

Amino acids are built from carbon, oxygen and hydrogen elements which react with nitrogen atoms. At least one hundred amino acids form a chain and this is how proteins as well as collagen are created.  In the case of collagen its amino acid composition of chains that causes their spiral shape (super helix ) .

The physiological process of ageing is a progressing alternation of soluble collagen from young tissue into an insoluble one as a result of biological process of connective tissue ageing.  Skin loses its elasticity and ability to expand because of the decreasing ability to retain water . Therefore , the decline in soluble collagen is a natural phenomenon in the ageing  process, but from a cosmetic point of view it is highly undesirable . Thus there is a justified necessity of supplementing protein deficiency through using cosmetics with soluble collagen, which has the role of a natural moistening substance.
 

The protein from the group of albumins ( keratin and collagen being two of them )is a main protein component of connective tissue, where collagen fibres built of single collagen cells   ( tropocollagen).
One cell of collagen consists of three dextrorotary chains which coiling around a common axis form a left-hand super spiral. Collagen cells are synthesized inside a cell, they permeate into inter -cell spaces where fibre forming takes place. Collagen is resistant to many enzymes . A peculiar enzyme which decomposes collagen is the enzyme produced by certain strains of bacteria. In hot water collagen swells, and after heating it to boiling state it undergoes denaturalization and transforms into gelatin, soluble in water protein which is susceptible to certain enzymes.
 

Collagen is one of the support proteins, providing skin with appropriate tightness, moisturisation, springiness, elasticity and suppleness . From the age of  25,  humans start to lose these features gradually, similar to muscles losing their strength, and bones diminishing in calcium.  All of the human ageing signs result from a progressing deficiency in soluble collagen, whose bio-synthesis is weaker and weaker with age. After the age of thirty , the atrophy of sebaceous and sweat glands starts in the body of nearly every human being and skin goes flabby and dry. Wrinkles appear as a consequence of weakening collagen fibres which are the main component of the under-layer of connective tissue. Toxins and some enzymes damage protein fibres and the levels of micro - elements, fibroblasts and vitamins stimulating collagen production decrease in the body. The turnover of collagen still lasts but the older the body is the more degeneration predominates the synthesis. Especially the synthesis of soluble collagen, which so far has guaranteed skin elasticity and expanding by providing it with water, weakens.