Biochemistry

compounds, they were called alkaline. Potassium is widely distributed in the Earth's crust (2.5% by weight). Potassium and sodium are present in biological media mainly in the form of Kf and Na' ions. Moreover, the normal concentration of K + is higher inside the cell, and the concentration of Na + is outside (in the interstitial fluid). The difference in the concentrations of these cations leads to the appearance of a membrane potential, the value of which is about 80 mV. Due to this, nerve fibers in the human and animal body are able to transmit impulses. The concentration of Na' and СГ mainly determines the osmotic pressure of blood plasma, as well as its acidity (pH). Kf ions regulate similar parameters in red blood cells and in the cells of other tissues. Potassium and sodium ions specifically affect the exchange of water in the body, but if K* enhances the return of water by cells and tissues, then Na + causes its accumulation. Antagonism between these cations can be traced in other biochemical processes: where K + activates enzymes, Na + inhibits them. The human and animal organisms may be having deficient in potassium. This is manifested in nausea, muscle and heart weakness, increased venous pressure, hallucinations. Later reflexes weaken or disappear and paralysis occurs. At the same time, an increase in the potassium content in the blood can lead to cardiac arrhythmia, clouding, etc. The elimination of potassium intoxication of the body is achieved by a protein-free and salt-free diet and the use of drugs. Molybdenum is a rather rare (1.1 — 1 0 4 % of the total mass of the earth ’ s crust) element. Molybdenum as a biogenic microelement is part of a number of important enzymes. It was found in the enzyme xanthineoxidase, which provides oxidation of purine bases to uric acid. For a number of animals and humans, uric acid is the end product of metabolism and is excreted from the body. When an increased amount of Mo is contained in food, a disease may occur associated with a violation of the metabolism of uric acid in the body and the deposition of its salts in various tissues and organs, mainly in the joints. This disease is called endemic gout. It is noted in those regions where soils contain an excess of molybdenum, for example, in England, the Netherlands, New Zealand, etc. Another negative consequence of the excess amount of Mo in food is disturbances in the development of the skeleton. They are due to the fact that molybdenum displaces phosphorus from bone tissue. As a metal activator, molybdenum is also necessary in amination reactions, for the inclusion of amino acids in the peptide chain, and in other biochemical transformations. With a molybdenum deficiency, growth a nd developmental delays in domestic animals and a decrease in their productivity at едфлрте/лыми кітапханасы 17 оқулык қоры мүлік • 2 7 0 6-2 - 9