Polyphosphates are anionic
phosphateA phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
polymers linked between hydroxyl groups and
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H
2...
atoms. The
polymerizationIn polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
that takes place is known as a
condensation reactionA condensation reaction is a chemical reaction in which two molecules or moieties combine to form one single molecule, together with the loss of a small molecule. When this small molecule is water, it is known as a dehydration reaction; other possible small molecules lost are hydrogen chloride,...
. Phosphate
chemical bondA chemical bond is an interaction between atoms or molecules and allows the formation of polyatomic chemical compounds. A chemical bond is the attraction caused by the electromagnetic force between opposing charges, either between electrons and nuclei, or as the result of a dipole attraction...
s are typically high-energy covalent bonds, which means that energy is available upon breaking such bonds in spontaneous or enzyme catalyzed reactions. Adenosine triphosphate (
ATPAdenosine-5'-triphosphate is a multifunctional nucleotide that plays an important role in cell biology as a coenzyme, that is, the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
) is an example of a phosphate trimer, a
polymerA polymer is a large molecule composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties.Due to the extraordinary...
with three phosphate groups.
Polyphosphates are anionic
phosphateA phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
polymers linked between hydroxyl groups and
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H
2...
atoms. The
polymerizationIn polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
that takes place is known as a
condensation reactionA condensation reaction is a chemical reaction in which two molecules or moieties combine to form one single molecule, together with the loss of a small molecule. When this small molecule is water, it is known as a dehydration reaction; other possible small molecules lost are hydrogen chloride,...
. Phosphate
chemical bondA chemical bond is an interaction between atoms or molecules and allows the formation of polyatomic chemical compounds. A chemical bond is the attraction caused by the electromagnetic force between opposing charges, either between electrons and nuclei, or as the result of a dipole attraction...
s are typically high-energy covalent bonds, which means that energy is available upon breaking such bonds in spontaneous or enzyme catalyzed reactions. Adenosine triphosphate (
ATPAdenosine-5'-triphosphate is a multifunctional nucleotide that plays an important role in cell biology as a coenzyme, that is, the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
) is an example of a phosphate trimer, a
polymerA polymer is a large molecule composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties.Due to the extraordinary...
with three phosphate groups. In many species they are stored in acidocalcisomes.
Sodium Tripolyphosphate
Sodium tripolyphosphateSodium tripolyphosphate , with formula Na5P3O10, is a polyphosphate of sodium...
, (Na
5P
3O
10), has been used widely as a constituent of laundry detergents, acting as a water softener in hard water regions and improving detergent performance. In recent years, concern has grown that this results in substantial amounts of phosphates entering the sewage system and thence to watercourses, resulting in
eutrophicationEutrophication is an increase in the concentration of chemical nutrients in an ecosystem to an extent that increases in the primary productivity of the ecosystem...
. This has led to the amounts of polyphosphates in detergents being legally controlled in a number of countries (e.g., Germany, Italy, Austria).
High-polymeric Inorganic Polyphosphates
High-polymeric inorganic polyphosphates were found in living organisms by L. Liberman in 1890. These compounds are linear polymers containing a few to several hundred residues of orthophosphate linked by energy-rich phosphoanhydride bonds.
Previously, it was considered either as “molecular fossil” or as only a phosphorus and energy source providing the survival of microorganisms under extreme conditions.
These compounds now known to also have regulatory roles and to occur in representatives of all kingdoms of living organisms, participating in metabolic correction and control on both genetic and enzymatic levels. Polyphosphate is directly involved in the switching-over of the genetic program characteristic of the logarithmic growth stage of bacteria to the program of cell survival under stationary conditions, “a life in the slow line”. They participate in many regulatory mechanisms occurring in bacteria:
- They participate in the induction of rpoS, an RNA-polymerase subunit which is responsible for the expression of a large group of genes involved in adjustments to the stationary growth phase and many stressful agents.
- They are important for cell motility, biofilms formation and virulence.
- Polyphosphates and exopolyphosphatases participate in the regulation of the levels of the stringent response factor, guanosine 5'-diphosphate 3'-diphosphate (ppGpp), a second messenger in bacterial cells.
- Polyphosphates participate in the formation of channels across the living cell membranes. The above channels formed by polyphosphate and poly-b-hydroxybutyrate with Ca2+ are involved in the transport processes in a variety of organisms.
- An important function of polyphosphate in microorganisms—prokaryotes and the lower eukaryotes—is to handle changing environmental conditions by providing phosphate and energy reserves. Polyphosphates are present in animal cells, and there are many data on its participation in the regulatory processes during development and cellular proliferation and differentiation—especially in bone tissues and brain.
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