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Polyphosphates are salts or esters of polymeric oxyanions formed from tetrahedral PO4 (phosphate) structural units linked together by sharing oxygen atoms. Polyphosphates can adopt linear or a cyclic ring structures. In biology, the polyphosphate esters ADP and ATP are involved in energy storage. A variety of polyphosphates find application in mineral sequestration in municipal waters, generally being present at 1 to 5 ppm.〔http://www.jacksmagic.com/pdfs/FAQ_phosphates.pdf〕 GTP, CTP, and UTP are also nucleotides important in the protein synthesis, lipid synthesis, and carbohydrate metabolism, respectively. == Structure== Image:Triphosphorsäure.svg|Structure of triphosphoric acid Image:Polyphosphoric acid.svg|Polyphosphoric acid Image:Trimetaphosphat.svg|Cyclic trimetaphosphate Image:Adenosindiphosphat protoniert.svg|Adenosine diphosphate (ADP) The structure of tripolyphosphoric acid illustrates the principles which define the structures of polyphosphates. It consists of three tetrahedral PO4 units linked together by sharing oxygen centres. For the linear chains, the end phosphorus groups share one oxide and the others phosphorus centres share two oxide centres. The corresponding phosphates are related to the acids by loss of the acidic protons. In the case of the cyclic trimer each tetrahedron shares two vertices with adjacent tetrahedra. Sharing of three corners is possible. This motif represents crosslinking of the linear polymer. Crosslinked polyphosphates adopt the sheet-structure Phyllosilicates, but such structures occur only under extreme conditions. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「polyphosphate」の詳細全文を読む スポンサード リンク
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