Phosphates/phosphorus high-energy

Pettegrew, J. W., Keshavan, M. S., Panchalingam, K. et al. Alterations in brain high-energy phosphate and membrane phospholipid metabolism in first-episode, drug-naive schizophrenics. A pilot study of the dorsal prefrontal cortex by in vivo phosphorus 31 nuclear magnetic resonance spectroscopy. Arch. Gen. Psychiat. 48 563-568,1991. 

About 10% of the acid-soluble phosphorus of the red blood cells in galactosemia is accounted for by galactose-l-phosphate. Since all this is derived from adenosine triphosphate by reaction (1), it represents the tying up in a metabolically useless form of a high proportion of the high-energy phosphate of the erythrocyte. Untreated galactosemics have... 

ATP Regarded as Store House of Energy Adenosine triphosphate (ATP) in a nucleotide consists of purine base adenine, a pentose sugar ribose and three molecules of phosphate. It contains two oxygen to phosphorus bonds between two phosphate units. These phosphorus bonds are called high energy phosphatic bonds. 

T. Kato, T. Shioiri, J. Murashita, H. Hamakawa, T. Inubushi and S. Takahashi, Later-alized abnormality of high-energy phosphate and bilateral reduction of phosphomo-noester measured by phosphorus-31 magnetic resonance spectroscopy of the frontal lobes in schizophrenia. Psychiatry Res., 1995, 61,151-160. 

Phosphorus-32, for example, produced by irradiating sulphur or natural phosphorus ( P) with high-energy particles, has a half-life of 14.8 days and can be rapidly taken up (in the form of phosphate) by body tissues such as muscles, the liver, bones, and teeth. De Hevesy found that different phosphorus compounds would be incorporated in a tissue-specific manner certain compounds were concentrated in the liver, for example. One can use stable isotopes as biological tracers too, since they are detectable atom by atom using mass spectrometry. De Hevesy observed that it takes deuterium twenty-six minutes to pass from ingested heavy water into urine. 

Gangadhar BN, Jayakumar PN, Subbakrishna DK, Janakira-maiah N, Keshavan MS. 2004. Basal ganglia high-energy phosphate metabolism in neuroleptic-naive patients with schizophrenia A 31-phosphorus magnetic resonance spectroscopic study. Am J Psychiatry 161 1304-1306. 

Solubilization, uptake, and precipitation of Ca and Si are directly (or at least energetically) linked to the photosynthetic and respiratory cycling of C, H, and O. Acids from nitrification and sulfur oxidation aid phosphorus mobilization photosynthesis or respiration is required for the uptake and conversion of phosphorous into high-energy phosphate. Sulfur is oxidized (with the concomitant reduction of nitrate) by Thiobacillus denitrificans, likewise, some extremely thermophilic methanogens can transfer hydrogen not only to CO2, but also to S. These are a few examples of interrelations involved in biogeochemical cycles. 

Figure 5.1 3 Na /K" -ATPase moves ion across the plasma membrane. The conformational change is triggered by ATPase activity, which phosphorylates an aspartate residue of the protein. Formation of a high-energy acyl phosphate bond drives the El -> E2 conformational change, which reverses when the phosphorus is eventually released. Na" " and K binding sites cycle between high affinity (semicircles in the schematic diagram) and low affinity (rectangles) states that are coordinated with the conformational change.

Following the elucidation of the glycolysis process by Embden and Mayerhof in 1932 and the glucose oxidation process by Krebs in 1937, the concept of high-energy phosphate bonds was introduced by Lipmann in 1941. By this time the intimate involvement of phosphorus compounds in numerous biochemical reactions had been firmly demonstrated. 

The effects of radiation on phosphorus compounds may be chemical, in which case bonds are broken, and ions, radicals or new molecules are formed, or they may be physical, such as the creation of holes (vacancies) or other defects in the crystal lattice. The effects of high-energy radiation on phosphorus compounds are important since x-rays and y-rays are used in food preservation, and organophospho-rus esters are used in the complexing of metals in the purification of nuclear fuels. The importance of the effects on phosphate esters present in living systems has long been recognised. 

The adenosine triphosphate (ATP) molecule is essential for life. It provides energy for muscle contraction, nerve conduction, many biochemical reactions, etc. At rest ATP turnover is 28 g (1 oz) of ATP per minute which is equivalent to 1.4kg (3 lb) per hour. During strenuous exercise, ATP turnover increases to a massive O.Skg/min Figure 10.1 shows that ATP consists of adenine, ribose and three phosphate groups that are identified as a-, P- and y-. Hydrolysis of the high energy phosphoanhydride bonds between the P- and y-phosphorus atoms, or alternatively, between the a- and P-phosphorus atoms releases energy for the biochemical reactions of life. 

Phosphorus (P) is present in both inorganic and organic compounds as phosphate. Nucleotide residues in nucleic acids are linked by phosphate bonds. Energy is transferred from one molecule (usually ATP) to another in the form of a high-energy phosphate bond. Many coenzymes also contain phosphate. 

ATP Synthesis. Inasmuch as the first steps in glucose metabolism start with the phosphorylation of hexoses in the presence of ATP, a direct effect of insulin on the formation of the high-energy phosphates could explain the effect of the hormone on glucose utilization, and an impairment of the rate of ATP synthesis could be responsible for the biochemical lesions of diabetes. Without ATP, glucose cannot enter the glycolytic cycle. Insulin could affect phosphorus metab-... 

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