Phosphates in Biology

Preparation of elemental phosphorus by reduction of phosphates is technically achieved by heating fluoroapatite with coke in the presence of Si02 (quartzite) in an electrical light-arc furnace at 1400-1500°C. In aqueous solution at pH 7.0, reduction of phosphate via phosphite, hypophosphite to elemental phosphorus and further to phosphine requires reduction at very low redox potentials, on average at -0.713 V (Table 1). It is not surprising, therefore, that reduced phosphorus compounds are very rare in nature, and that the dominant phosphorus form in nature is the phosphoric acid or phosphate form. 

In the following sections, the interaction of phosphorus compounds with living systems will be discussed in detail. 

Since phosphate does not change its redox state in living cells (except in a few instances, see below), it is present in the cell only as free inorganic phosphate, as esters or as acid anhydrides, e.g., as constituent of nucleotides and their 

Phosphate Uptake by Algae, Bacteria, and Higher Plants 

Numerous algae, cyanobacteria and heterotrophic bacteria are known to take up phosphate at sufficient supply far beyond their physiological needs ( luxurious uptake ), and to store it inside in the form of polyphosphate ( volutin granula ) which can make up up to 15% of total bacterial cell mass. In these polyphosphates, the phosphoryl units are linked by acid anhydride linkages which are synthesized through polyphosphate kinase, according to Reaction (1) 

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Banes, E. D. In Calcium Phosphates in Biological and Industrial Systems, Amjad, Z., Ed. 1998, Kluwer Academic Publ., Boston, 21. 

J. P. Yesinowski, Nuclear magnetic resonance spectroscopy of calcium phosphates, in Z. Amjad (Ed.), Calcium Phosphates in Biological and Industrial Systems, Kluwer Academic Publishers, Norwell, MA, 1998, pp. 103-143. 

Mechanisms may be readily envisaged where this reaction may lead to phos-phoryl transfer through nucleophilic attack with ring opening on phosphorus followed by hydrolysis of the acyclic acyl phosphate. In biological systems this may function as an alternative to the metaphosphate reaction. 

Table 9.4 Analytical procedures for the determination of alkyl phosphates in biological samples... 

Butcher, R.W., and Sutherland, E.W. (1962) Adenosine 3, 5 -phosphate in biological materials. I. Purification and properties of cyclic 3, 5 -nucleotide phosphodiesterase... 

Min, J. K., Yoo, H. S., Lee, E. Y., Lee, W J., Lee, Y.M. Simultaneous quantitative analysis of sphingoid base 1-phosphates in biological samples by o-phthalaldehyde precolumn deri-vatization after dephosphorylation with alkaline phosphatase. Anal Biochem 303 (2002) 167-175. 

C. Phosphates in Biological Materials (Nonprocessed Foods, Fauna, and Flora). .. 277... 

Phosphorus nuclear magnetic resonance (NMR) (Tables 5.7 and 10.5) rose to importance as the presence of phosphates in biological systems became amenable to study. 

Paper partition chromatography (PPC) was the first used for separating thiamine phosphates in biological materials. A good PPC separation of thiamine phosphates was reported by using several different solvent systems. Photometry at 270 nm of eluted, individual spots allowed quantitation of each thiamine compound down to the lO-pg level. 

S AUenmark, E Hjelm, U Larsson-Cohn. New method for quantitative analysis of pyridoxal-5 -phosphate in biological material. J Chromatogr 146 485-489, 1978. 

A Hamfelt. A simplified method for determination of pyridoxal phosphate in biological samples. Uppsala J Med Sci 91 105-109, 1986. 

HoeferUn LA, Wijesinghe DS, Chalfant CE. The role of ceramide-l-phosphate in biological functions. Handb Exp Pharmacol. 2013 215 153-166. 

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