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Organoselenium chemistry. Organoselenium chemistry is the science exploring the properties and reactivity of organoselenium compounds, chemical compounds containing carbon -to- selenium chemical bonds. [ 1][ 2][ 3] Selenium belongs with oxygen and sulfur to the group 16 elements or chalcogens, and similarities in chemistry are to be expected.
Selenium in biology. Selenocysteine is the main organic molecule involving selenium in humans. Selenium is an essential micronutrient for animals, though it is toxic in large doses. In plants, it sometimes occurs in toxic amounts as forage, e.g. locoweed. Selenium is a component of the amino acids selenocysteine and selenomethionine.
Snails are a good source of selenium. Of the recommended daily requirement of selenium, the snail provides up to 50% (in women) and 30% (in men). [21] Snail flesh is a good supply of essential amino acids such as lysine, methionine, and cysteine, which are difficult to get in other sources of protein, according to Adeyeye et al. (2020).
Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells.
Selenium is toxic in high concentrations. As sodium selenite, the chronic toxic dose for human beings was described as about 2.4 to 3 milligrams of selenium per day. [7] In 2000, the US Institute of Medicine set the adult Tolerable upper intake levels (UL) for selenium from all sources - food, drinking water and dietary supplements - at 400 μg/day. [8]
Organometallic chemistry. n -Butyllithium, an organometallic compound. Four lithium atoms (in purple) form a tetrahedron, with four butyl groups attached to the faces (carbon is black, hydrogen is white). Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon ...
The selenium cycle is a biological cycle of selenium similar to the cycles of carbon, nitrogen, and sulfur. Within the cycle, there are organisms which reduce the most oxidized form of the element and different organisms complete the cycle by oxidizing the reduced element to the initial state. In the selenium cycle it has been found that ...
Irradiation of food [20] is the exposure of food to ionizing radiation. Multiple types of ionizing radiation can be used, including beta particles (high-energy electrons) and gamma rays (emitted from radioactive sources such as cobalt-60 or cesium-137). Irradiation can kill bacteria, molds, and insect pests, reduce the ripening and spoiling of ...