What are proteins?
The proteins are organic molecules that are composed of amino acids. The basic distribution of a protein is a chain of amino acids, and it consists of twenty different shapes, which are coupled together by peptide bonds. These molecules are characterized by using information encoded in genes to assemble.
Proteins are the support of life, living organisms need them to repair and maintain themselves. That is to say, they fulfill an essential function in the maintenance of the body, in the repair and manufacture of new cells.
Classification of amino acids
According to their type, proteins can be classified into:
1. Simple proteins or holoproteins: through hydrolysis, that is, when degrading, they produce only amino acids .
2. Conjugated proteins or heteroproteins: like simple proteins , when degrading, they cause amino acids, but also other organic and inorganic compounds . The non-prosthetic fraction of one of these proteins is designated by the name of “prosthetic group”.
This diversity of proteins is subclassified taking into account the nature of their prosthetic assemblages in:
- Nucleoproteins (Nucleic Acid)
- Metalloproteins (Metal)
- Phosphoproteins (Phosphate)
- Glycoproteins (Glucose)
Other features to keep in mind
It should be considered that, due to their conformation, we have fibrous proteins, which are specified as protective systems, strands, being an example of these, keratin in hair and skin, as well as in cuticles, and others such as muscle contraction myosin and elastin from connective tissue. They are bodily resistant and are not soluble in water.
On the other hand, globular proteins are established by folded polypetidic ligatures, accepting compact spherical or globular forms. This is the case with enzymes, antibodies and hormones. They perform a dynamic function inside the cell, and in general, if they are small, they are available in aqueous structures.
Within proteins, six categories can be established:
- Albumin : they are large molecules that dissolve in water and coagulate by heat . We can find them in the albumin in the egg, in the blood serum, in the casein of milk and in many plants.
- Globulins : large molecules , soluble in water and coagulate at high temperatures. These are discovered in the antibodies in the blood, in the serum, in the egg and basically in the seeds.
- Prolamines : they do not dissolve in water , but they do dissolve in aqueous ethanol solutions.
- Glutelins : they are soluble in dilute acid and base solutions, and cannot be dissolved in water.
- Histones : proteins of low molecular abundance, in addition to being soluble in water . They are localized in association with nucleic acids, and they do not coagulate simply by heat.
- Prolamines : They contain essential amino acids. They do not coagulate with heat or dissolve in water or absolute alcohol, only 60 and 80%.
Proteins according to their origins
Going into the origin of proteins, and in correspondence with our nutrition, we can also discover that proteins are classified into proteins of animal or vegetable origin:
-In the case of proteins of animal origin, they consist of two types:
- Fibrous: they assume as occupation, the protection and support of the tissues.
- Globular: organized by liquids that are possible to assimilate and that have a high content of fundamental amino acids.
-In the case of proteins of plant origin , the following can be distinguished:
- Glutelins: they are very flexible cells, founding the essential element of gluten.
- Prolamines: proteins that are easily dissolved in alcohol.