Biogenic Elements: What They Are, Types And Functions
All living beings on Earth are composed of organic matter. The basic structures that make up the different taxa (both animals and plants and microscopic organisms) are cellulose, tannin, cutin and lignin, along with other proteins, lipids and sugars that build tissues and cell covers. All this matter is not created as such from nothing, but is transformed through the energy flows of biogeochemical cycles.
Plants transform waste and inorganic matter into organic tissues using solar energy (photosynthesis), herbivores consume enormous quantities of this matter and then the tissue generated is passed to higher levels of the food chain, as carnivores and superpredators. When a living being dies, its tissues decompose into matter and nutrients, which once again become part of the plant vascular system by root absorption, thus closing the cycle.
In this way, we demonstrate with a series of general strokes how organic matter and energy fluctuate in the different stratifications of an ecosystem. In any case, to understand the functioning of living beings we must delve to a much more microscopic level, of atoms and molecules. Join us on this journey through the biogenic elements because in them is the key to life.
The etymological root of the word itself can help us introduce this term. In Greek, bio It means life and genesis origin. Thus, it is easy to assume that the biogenic element is that which allows life, forming part of the tissues and/or metabolic pathways of living beings. Although the living matter of the world is composed of about 25-30 biogenic elements, only 8 of them are the most dominant and widespread throughout the taxa
At this point, it should be noted that a chemical element is a type of matter made up of atoms of the same type, with a certain number of nuclear protons in its simplest form. There are a total of 118 chemical elements on Earth, of which 26 have been obtained under laboratory conditions. Of the remaining 92, only 27 are considered bioelements (or biogenic elements, interchangeable terms). Their classification is distributed as follows:
What are the most important types of biogenic elements?
As we have said, primary bioelements form almost all the matter we know. Therefore, we are going to focus on the 6 biogenic elements par excellence (carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur), and then do a brief review of the secondary bioelements and trace elements. Do not miss it.
1. Carbon (C)
Carbon is the bioelement or biogenic element par excellence. It is estimated that the Earth houses 550 billion tons (550 Gt) of carbon on its surface, of which 450 Gt (80%) is stored in plant matter. Forests are not only the lungs of the planet, but they also represent the first energy reserve, in the form of plant biomass. After this group, it should be noted that bacteria contribute about 70 Gt to the Earth’s surface, despite their individual microscopic biomass.
As abundant as we are, it is incredible to know that human populations only account for 0.06 Gt of the total planetary organic carbon. Paradoxically, this is the second most present element in our body (up to 20%), only surpassed by the oxygen that flows through all our veins, arteries and blood capillaries.
2. Oxygen (O)
Measured based on its total mass, oxygen is the third most present chemical element on Earth, surpassed only by helium (He) and hydrogen (H). In any case, it is the most abundant if the limit is limited to the Earth’s crust, since it makes up more or less half of its mass.
Proteins, nucleic acids, carbohydrates, lipids and water contain oxygen, so it is essential for the construction of complex organic matter Furthermore, water (H2O) uses this biogenic element as a pillar. Without O2, we are nothing.
Hydrogen (H) is the first element of the periodic table for good reason: It is the most abundant biogenic element on Earth, since it accounts for 75% of all visible mass in the universe We are moving in figures incomprehensible to the human mind, but it is clear to us that almost everything present on the corporeal plane is, to a greater or lesser extent, hydrogen.
Hydrogen is not only part of living matter, but is an element found in abundance in stars and gaseous planets. Under normal conditions, this biogenic element occurs in the form of diatomic gas (H2).
4. Nitrogen (N)
Nitrogen makes up 78% of atmospheric air, making it the main component of the Earth’s atmosphere. Within living beings, this element is essential for the formation of amino acids and nucleic acids The former give rise to the proteins of all living solid tissues, while the latter are responsible for forming DNA and RNA.
Furthermore, nitrogen cycles in ecosystems are considered the most important, since this biogenic element is the one that most promotes plant growth under the appropriate conditions. Without nitrogen, events as diverse as biological inheritance or dense forests would be impossible.
5. Phosphorus (P)
Phosphorus is another essential element for life, although it is found in a lower proportion than the rest in the gross calculation of the Earth’s mass.
The phosphate group (of which it is a part) is essential for the synthesis of DNA and RNA, so, as with nitrogen, genetic inheritance occurs thanks to it It is also part of the lipid bilayer, the membrane that separates cells from the organic or inorganic environment that surrounds them.
6. Sulfur (S)
Sulfur is another of the essential biogenic elements to understand life. It is part of the amino acids cysteine and methionine and, consequently, it is necessary for protein synthesis in all living beings on the planet.
Based on their concentrations in the tissues of living beings, these elements are considered secondary at the level of pure mass, but equally important for the maintenance of existence. In this group, potassium, calcium, chlorine, magnesium and iron stand out, among others. For example, Calcium is one of the essential elements for the formation of bone tissue in living beings since 99% of an organism’s Ca is in the bone system.
8. Trace elements
Despite representing only 0.1% of vital organic matter, trace elements are also necessary for life in small quantities. This includes cobalt, fluorine, chromium, copper, silicon, iodine and zinc, among others It should be noted that its absence in the body can be lethal, but so can its excessive presence. In atypical concentrations, they can cause liver toxicity.
Summary
As you can see, living beings are nothing more than atoms and elements invisible to the human eye, which are organized in a more or less complex way to give rise to all the life we know. Human beings are almost 20% carbon, 60% water and the remaining percentage (up to 99%), the other biogenic elements mentioned. If any of them did not exist, the tissue organization that characterizes us would be impossible.
From the chromosomes of a cell to the Amazon forests, every level of living organization passes through the 6 main biogenic elements: carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. In the end, at a microscopic and basal level every living being is reduced to the same thing.
