Biochemistry

Cobalt is a rather rare element on Earth (1.8-10' 3 % of the mass of the Earth's crust). In nature, this element is more common with iron, sulfur and arsenic. The role of cobalt in biological systems is due to the fact that it is part of vitamin Bl 2 (cyancobalamin), which is necessary for the vital functions of the human and animal organisms. In addition, this element is involved in protein and carbohydrate metabolism, activates peptidase enzymes (break down proteins into amino acids), phosphatases (hydrolyzes phosphoric esters of carbohydrates and proteins). In particular, Co 2+ activates the enzyme bone phosphatase and thereby contributes to the deposition of insoluble phosphates in the bone tissue. Cobalt is found in all tissues and organs of humans and animals. Faster, it accumulates in the endocrine glands: - pituitary, thymus, adrenal glands, as well as in the spleen and pancreas. Significant amounts of this trace element are found in the thyroid gland, lungs, liver, and ovaries. The lack of cobalt in human food leads to a weakening of the synthesis of vitamin В 12 and, as a result, to malignant anemia. Excessive intake of cobalt in the body can cause skin damage - dermatitis and general intoxication, primarily among workers in the metallurgical industry. Signs of cobalt poisoning are a violation of the functions of the digestive system, respiration, circulatory system and other pathologies. Vanadium. Its content in the earth's crust is 1.5-1 O' 2 % by weight. Vanadium is constantly present in the tissues of all organisms in negligible amounts. In plants, its content (0.1-0.2%) is significantly higher than in animals (КГМСГ^). Vanadium and its compounds are toxic in large doses. Toxic dose to humans 0.25 mg, lethal dose 2-4 mg. With severe vanadium poisoning, anemia occurs, kidney damage, mental disorders (hysteria, melancholy). Chromium. In the Earth's crust it contains 8.3-10' 3 % by weight. Chromium is part of more than 40 different minerals. Entering the body of an animal and a person, chromium can affect the metabolism. In particular, it is able to lower blood cholesterol, and a deficiency of this trace element can cause atherosclerosis. Chromium has the ability to bind to the pancreatic hormone insulin and enhance its effect on the carbohydrate metabolism of the body. At the same time, all soluble compounds of this metal, especially Cr 6+ in large doses, are poisonous. Acting as strong oxidizing agents, they can oxidize blood hemoglobin Fe 2 ’ to Fe 3+ . As a result, hemoglobin turns into methemoglobin, which is not able to carry out oxygen transfer. The characteristic symptoms of chromium poisoning are headaches, emaciation, shortness of breath, bronchitis, damage to the liver and pancreas. 18