What are bioelements and their classification

Bioelements, which are also called biogenic elements (from “bio” – “life” and “genesis” – “origin”, that is, they give rise to living forms), are the chemical elements that make up living beings and they can be found both alone and in conjunction with others, forming biomolecules. There are around 70 bioelements, although not all of them are present in all living beings nor are they in the same proportions.

Among the most common elements for their abundance in living beings we find oxygen, carbon, hydrogen and nitrogen. It is curious that, with the exception of oxygen and hydrogen, bioelements are not the most abundant chemical elements in the physical environment and, nevertheless, are essential for the support of life. The reason for this is given by a series of characteristics and properties that are common to these biogenic elements, among which are:

• Its ease of establishing stable covalent bonds with each other due to its low atomic mass which, together with the fact that the electrons they share are close to the nucleus, favors the formation of stable molecules.
• Covalent bonds between bioelements, especially when oxygen or nitrogen (which are especially electronegative) are involved, often result in the formation of polar water-soluble molecules, which tends to be the environment in which biological reactions take place. , so these are facilitated.
• Bioelements are easily incorporated by living organisms from the environment, as they are usually found as part of simple molecules such as H2O or CO2, which facilitates the continued exchange of these elements between the physical environment and living matter.

There are different types of bioelements : classified according to their relative abundance in living organisms in the majority, essential trace elements and non-essential trace elements . The majority bioelements are characterized by being always present in living organisms. Within this group, 2 subgroups of bioelements are distinguished: primary and secondary bioelements .

Then, in the following sections, the different types are exposed and what is the function of the primary bioelements and the secondary bioelements, as well as of the trace elements.

The primary bioelementos are in an approximate ratio of 95% in the living matter and are essential for the formation of biomolecules. Primary bioelements include:

• Carbon: essential element in the formation of hydrocarbon chains through single or double bonds that serve as the backbone of large molecules. Here we explain to you what is the importance of carbon in living beings .
• Hydrogen: the other essential element in hydrocarbon chains, apart from being part of the water molecule.
• Oxygen: it is part of such essential molecules as H2O, CO2, and so on.
• Nitrogen: constitutive element of amino acids and nucleic acids, generally present in amino form (-NH2).
• Phosphorus: necessary for the synthesis of ATP (adenosine triphosphate), an essential molecule to provide energy in the biochemical reactions that take place in living beings.
• Sulfur: structural component of proteins through the establishment of disulfide bonds.

For their part, secondary bioelements are somewhat less abundant than primary ones but play essential roles in cell physiology. Among the secondary bioelements are:

• Calcium: it is commonly found in nature, forming calcium carbonate, a fundamental element in the skeletons and shells of crustaceans, mollusks and many other living organisms. Furthermore, calcium is involved in muscle contraction processes.
• Sodium: together with potassium and chlorine, they are abundant in the internal cell environment and are essential to maintain salinity and the balance of electrical charges in the cell plasma membrane. It also plays an important role in the transmission of the nerve impulse.
• Potassium: involved in the transmission of the nerve impulse, along with sodium.
• Magnesium: appears as a cofactor of several enzymes, as well as being part of chlorophyll.
• Chlorine: maintains polarity within the cell and the permeability of cell membranes, among other functions.

Essential trace elements are found in living organisms in a proportion that does not exceed 0.1%, which does not diminish their essential character, and both their absence and excess can cause important deficiencies and problems in the body. Within the group of essential trace elements include:

• Iron: essential element in hemoglobin (for oxygen transport) and in the cytochromes of the respiratory chain.
• Manganese: is part of various enzymes, such as superoxide dismutase, with antioxidant activity.
• Copper: compound of the pigment hemocyanin.
• Zinc: involved in growth processes, in the synthesis of insulin and in the defense of the immune system.
• Fluorine: provides resistance to bones and teeth.
• Iodine: a fundamental element in the formation of the thyroid hormone thyroxine.
• Boron: essential in plant species for the maintenance of the cell wall.
• Silicon: necessary in the formation of the skeleton and in bone calcification.
• Chromium: involved in the metabolism of sugars and favors the introduction of glucose into cells.
• Vanadium: essential in certain organisms other than humans.
• Cobalt: is part of vitamin B12, necessary for the proper functioning of the nervous system.
• Selenium: has an antioxidant function and is important for proper muscle function.
• Molybdenum: intervenes in the production of uric acid and favors the proper functioning of xanthine oxidase, an enzyme in charge of iron metabolism.
• Tin: benefits the immune system and is necessary for certain bioelectrical functions.

Finally, non-essential trace elements are made up of all those chemical elements that, without being essential for all living beings, often play important functional roles in them.

Having understood what bioelements are and what their classification is , we can approach the concept of immediate principles, which are the combined forms in which bioelements are usually found. There are physical methods such as evaporation, filtration, distillation and centrifugation, among others, that allow the separation of these components from living matter without altering its molecular structure.

The immediate principles can be divided into organic immediate principles – the so-called biomolecules , which include carbohydrates, lipids, proteins and nucleic acids and which are exclusive to living matter and, therefore, have to be synthesized by living beings. or immediate inorganic principles , among which are water and mineral salts (solid or in solution) that, in addition to living beings, are also present in inorganic matter. In turn, biomolecules can be simple, if they are formed by the union of several atoms of the same element (for example, oxygen, O 2), or compound, when they are composed of the combination of atoms of different chemical elements (as in the case of water, H 2 O ).

Biomolecules have structural functions (as occurs with proteins, lipids and mineral salts), energetic (carbohydrates and lipids) or catalyst of reactions (as in the case of enzymes, which are proteins).

To continue learning about these issues and progress in the matter, we recommend this other AgroCorrn article on What is organic and inorganic matter .