Basic biogenic elements

Almost every one of the chemical elements plays some role in Earth’s living systems, however, 20 elements account for the vast majority of material in living systems. These biogenic elements are divided into:

six major biogenic elements (elements found in almost all of Earth’s living systems, often in relatively large quantities), five minor biogenic elements (elements found in many of Earth’s living systems, and/or in relatively small quantities), trace elements (essential elements necessary only in very small quantities to maintain the chemical reactions on which life depends.

The biogenic elements can be classified as:

Macroelements (or macrominerals) – the content in the organism is more than 10-2%. Microelements (or trace elements) – the content in the organism is 10-3 – 10-5 %. Macroelements are elements found in almost all of Earth`s living systems. There are 11 of them. Six are colled organogens ore major biogenic elements. The content of them is 97% in the organism. Major biogenic elements or organogens carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorous;    minor biogenic elements sodium, potassium, magnesium, calcium, chlorine.

Microelements are essential elements necessary only in very small quantities to maintain the chemical reaction on which life depends. These are: biogenic trace elements: manganese, iron, cobalt, copper, zinc, boron, aluminum, vanadium, molybdenum, iodine, silicon, nickel, bromine. According to their abundance in the organism , biogenic elements can be classsified into macroelements, microelements and contaminating elements. Macroelements (12 elements in total) form up to 99 % of any organism, and can be further subdivided into:

• a)    a group of stable primary elements (1-60 % of total organism weight). These are: O,C, H,N.

• b)    a group of stable secondary elements (0.05/1 % of total organism weight). These are Ca, S, Mg, Cl, Na, K, Fe.

Microelements can be divided into three categories:

• a)    a subgroup of 8 stable elements (less than 0.05%). These are the elements: Cu, Zn, Mn, Co, B, Si, F, I.

• b)    a subgroup of approximately 20 elements that are present at conc. of 0.001% and lower.c) a subgroup of contaminating elements: Their constant excess in the organism leads to disease: Mn, He, Ar, Hg, Tl, Bi, Al, Cr, Cd.

According to their physiological importance, biogenic elements are essential and nonessential.

Essential elements can be divided into two groups:

• a)    main essential elements, such as Ca, Mg, Na, K, P, S, Cl, they are present in food. They usually play multiple roles.

• b)    trace essential elements.

Calcium: (ca)

A soft grey metal from Group II of the periodic table. It is moderately reactive. Calcium is the fifth most common element in the earth system by weight. calcium compounds are found in many common rocks, e.g., limestone and chalk (calcium carbonate, CaCO3. Calcium is essential to living things: Plants require calcium to build cell walls. Animals require calcium to build bones and teeth. Calcium is present in bones in the form of hydroxyapatite (Ca3(PO4)2), Ca(OH)2. Calcium present in ionic form, serving as an important regulator of processes in cell cytoplasm. Biological importance of calcium: it affects neuromuscular excitability of muscle (together with ions K, Na and Mg and takes part in muscle contraction. Hypocalcemia leads to cramps-tetany it takes part in regulation of glycogenolysis in muscle and of gluconeogenesis in kidney and liver it decreases cell membrane and capillary wall permeability, what results in its antiinflammatory, antiexudative and antiallergic effects. It is necessary for blood coagulation. Calcium ions are important intracellular messengers, influencing secretion of insulin into the circulation and secretion of digestion enzymes into small intestine. Calcium resorption is affected by the mutual ratio of calcium to phosphates in the intestinal content, and bythe presence of cholecalciferol, which regulates active resorption of calcium and phosphorus.

Magnesium (Mg)

Magnesium is the seventh most common element in the Earth System by weight. Magnesium is an essential component of chlorophyll. Is a typical intracellular cation. Is an essential part of tissues and body fluids. Is present in skeleton (70 %) and muscles of animals .

Sodium (Na)

Potassium (K)

Potassium is the sixth most common element in the Earth System by weight important intracellular ion take part in homeostasis of the organism. Takes part in spreading of nerve excitation. Deficiency of potassium leads to heart arrest.

Phosphorus (P)