Polyphosphate
Triphosphates are salts or esters of polymeric oxyanions formed from tetrahedral PO4 (phosphate) structural units linked together by sharing oxygen atoms. When two corners are shared the polyphosphate may have a linear chain structure or a cyclic ring structure. In biology the polyphosphate esters AMP, ADP and ATP are involved in energy transfer. A variety of polyphosphates find application in mineral sequestration in municipal waters, generally being present at 1 to 5 pm. GTP, CTP, and UTP are also nucleotides important in the protein synthesis, lipid synthesis and carbohydrate metabolism, respectively.
Read more about Polyphosphate: Structure & Formation, Acid-base and Complexation Properties, The "high Energy" Phosphate Bond, High-polymeric Inorganic Polyphosphates