Living organisms phosphorus

Phosphorus compounds are very important as fertilizers (world use 1976/77 27-3 megatonnes as P2O5) but are widely used in matches, pesticides, special glasses and china ware, alloys (sleels. phosphor bronze), and metal treating (10%), detergents (40%), electrical components (e.g. GaP), foods and drinks (15%). Phosphates are an essential constituent of living organisms. U.S. production of phosphorus 1982 372 000 tonnes. 

Toxic compounds that can be absorbed to a marked degree by a living plant through either its roots or its leaves have been called by British investigators systemic insecticides. Schrader (38) first found this peculiar property in certain acetals of 2-fluoroethanol and bis-(2-fluoroethoxy) methane, as well as in certain compounds of his organic phosphorus series, notably bis(dimethylamido)fluophosphate and octamethyl pyrophosphoramide. 

Phosphorus in living organisms is mainly important as phosphate... 

Different roles in aquatic ecosystems, from acting as nutrients for living organisms (nitrogen and phosphorus compounds) to exerting toxic effects on such organisms (arsenic and mercury). 

Nutrients—these are elements essential to the metabolism of living organisms. Nitrogen, phosphorus, and silicon are the most important and commonly studied nutrients in aquatic ecosystems. 

Derivatives of phosphoric acid, pyrophosphoric acid, and related compounds are very important in biological systems. Pyrophosphoric acid is an anhydride of phosphoric acid. Adenosine triphosphate, an energy carrier that is universally found in living organisms, has a phosphorus dianhydride connected to an adenosine group by a phosphate ester linkage. Phosphorus ester bonds are used to form the polymeric backbone of DNA (see Chapter 27). 

Like other dissolved organic nutrients, the chemical composition of organic P is relatively unknown. Marine dissolved organic phosphorus (DOP) composition has been mostly identified as particular compound classes such as monophosphate esters, phosphonucleotides, nucleic acids, phospholipids, phosphonates and polyphosphates (Benitez-Nelson, 2000). Kolowith et al. (2001) found that monophosphate esters and phosphonates are major components in the Pacific Ocean, the Atlantic Ocean and the North Sea. ATP (adenosine triphosphate), ubiquitous in aU living cells, has been used as a model DOP compound in radiotracer experiments to obtain information on P sources and fluxes in natural environments (Bjorkman et al., 2000 Karl and Bossard, 1985) and cyanobacterial cultures (Fu et al., 2006). 

Phosphorus occurs in nature mainly as the minerals apatite, Ca5(P04)3F, hydroxy-apatite, Ca,r,(P04)3(0H), and tricalcium phosphate (phosphate rock, ranging in composition from Ca3(P04)o to hydroxyapatite). Kydroxy-apatite is the main mineral constituent of the bones and teeth of animals, and complex organic compounds of phosphorus are essential constituents of nerve and brain tissue and of many proteins, and are involved significantly in the metabolic reactions of living organisms. 

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