Manganese ions plants

Manganese ions enzyme activators, 6,578 probes, 6,563 RNA polymerases activation, 6, 585 transport microbes, 6, 569 plants, 6, 572 Manganese oxide colloidal... 

The enzyme responsible for the photolysis of water in plants is a multisubunit membrane protein (Fig. 5-22 Klein et al., 1991). Four manganese ions, probably as a tetranuclear cluster, are thought to act as a charge accumulating system and as the active site for water oxidation. Both calcium and chloride ions are also required for activity (Babcock, 1987 Ghantokakis and Yocum, 1990). The water oxidation centre (WOC) contains a total of four Mn atoms and causes the oxidative coupling of two water molecules by a currently unknown mechanism. 

Maton, J. The influence of manganese ions on the synthesis of ascorbic acid in the green parts of higher plants Biol. Jaarboek Koninkl. Natuurn. Genootschap Dodonaea Gent. 14 (1947) 109-115, see Chem. Abstr. 

Engelsma, A possible role of divalent manganese ions on the photoinduction of phenylalanine ammonia-lyase. Plant Physiol. 50, 599 (1972). Engelsma, Induction of phenylalanine ammonia-lyase by dichlobenil in gherkin seedlings,... 

Precipitation is often applied to the removal of most metals from wastewater including zinc, cadmium, chromium, copper, fluoride, lead, manganese, and mercury. Also, certain anionic species can be removed by precipitation, such as phosphate, sulfate, and fluoride. Note that in some cases, organic compounds may form organometallic complexes with metals, which could inhibit precipitation. Cyanide and other ions in the wastewater may also complex with metals, making treatment by precipitation less efficient. A cutaway view of a rapid sand filter that is most often used in a municipal treatment plant is illustrated in Figure 4. The design features of this filter have been relied upon for more than 60 years in municipal applications. 

Chemical precipitation is used in porcelain enameling to precipitate dissolved metals and phosphates. Chemical precipitation can be utilized to permit removal of metal ions such as iron, lead, tin, copper, zinc, cadmium, aluminum, mercury, manganese, cobalt, antimony, arsenic, beryllium, molybdenum, and trivalent chromium. Removal efficiency can approach 100% for the reduction of heavy metal ions. Porcelain enameling plants commonly use lime, caustic, and carbonate for chemical precipitation and pH adjustment. Coagulants used in the industry include alum, ferric chloride, ferric sulfate, and polymers.10-12... 

Manganese dioxide can be used to absorb the initially low concentration SO2 to produce the sulphate in a Mitsubishi Process (23). In this case the absorbing phase is itself the oxidising agent. Regeneration with ammonia and air simultaneously produces ammonium sulphate which can be directly marketed as a fertiliser, thus the calcium ion problem of the dry limestone process is replaced by a plant nutrient ion -... 

York and New England are devoid of fish due to the effects of acid rain. Indirect effects of the low pH values associated with acid rain also affect organisms. As noted in Table 13.1, one of the properties of an acid is the ability to dissolve certain metals. This has a profound effect on soil subjected to acid rain. Acid rain can mobilize metal ions such as aluminum, iron, and manganese in the basin surrounding a lake. This not only depletes the soil of these cations disrupting nutrient uptake in plants, but also introduces toxic metals into the aquatic system. 

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