Phosphate bond energy

The end phosphate adds water and is transferred onto another compound, causing thereby the phosphorylation of the latter. An alternative route for the phosphate bond energy release is exemplified by pyrophosphate cleavage of ATP ... 

In 1931 Lundsgaard suggested that the energy used in muscle contraction was derived from phosphate bond energy supplied by glycolysis or respiratory oxidation. 

Lipmann, F.(1941). The metabolism, generation and utilization of phosphate bond energy. Adv. Enzymol. 1,99-162. 

F. Lipmann, Metabolic Generation and Utilization of Phosphate Bond Energy , Adv. Enzymol., 1, 99-162 (1941). 

Isotopic experiments (763) with tryptophan labeled with N and deuterium in the indole ring have shown that quinolinic acid nitrogen is probably entirely derived from the indole nitrogen of tryptophan, and that scission of the benzene ring probably occurs between carbons 3 and 4. Presumably, therefore, the hydroxyanthranilic acid is converted to intermediate A without participation of a catechol-type intermediate, and it is possible that the phosphate-bond energy of hydroxyanthranilic acid phosphate (if this is in fact an intermediate) may contribute to the transformation. It is known... 

PEP carboxylase avoids the thermodynamic problem of enolate formation by beginning with PEP instead of pyruvate. Provided that the enolate is shielded from solvent, this offers a thermodynamically favorable approach to the car-boxylation step. PEP carboxylase achieves a high concentration of CO2 at the active site of the enzyme by starting with HCOs" and using the phosphate bond energy to dehydrate it. Protection of the active site from solvent is also important in order to ensure that CO2 is available for reaction with the enolate, rather than dissociating. 

Cells use GTP and CTP, as well as UTP and ATP, to form activated intermediates. Different anabolic pathways generally use different nucleotides as their direct source of high phosphate bond energy UTP is used for combining sugars, CTP in lipid synthesis, and GTP in protein synthesis. 

Coupled to either phosphate bond energy or oxidative reactions. Products of oxidation Include pmf and reducing equivalents. 

Phosphate-bond energy is readily utilised in biochemical reactions and is the only form of energy that can be utilised by any living ceU. High energy of hydrolysis is not found in any other chemical system. 

In some cases, phosphate bond energy is transferred from ATP to alternative triphosphates which are subsequently utilised in various biosynthetic processes (Figure 11.18). These nucleoside triphosphates (11.29) are produced when ATP phosphorylates the appropriate nucleoside diphosphate in enzyme-catalysed reactions such as... 

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. 

II. Utilization of Phosphate Bond Energy for Thiol-ester Synthesis.. 192... 

It was evident from early studies that in the presence of CoASH, ATP could in some way be used to activate acetate so that it will acetylate sulfanilamide (7) and choline (8). Chou and Lipmann (9) succeeded in partially purifying the enzyme(s) responsible for this activation from pigeon-liver extracts and they concluded that the phosphate bond energy of ATP is utilized to bring about the synthesis of acetyl coenzyme A (acetyl-SCoA) however, the mechanism of this activation remained obscure. The nature of the over-all process was further elucidated through the experiments of Lipmann et al. (10) who demonstrated that ATP, CoASH, and acetate react to form acetyl-SCoA, AMP, and inorganic pyrophosphate (P-P) in stoichiometric amounts [reaction (4)]. They also demonstrated that the reaction is freely reversible. More recently, the studies of Jones et al. (11) have indicated that the mechanism of this conversion is as follows ... 

The percentage of the total energy of oxidation of palmitate (9800 kJ or 2340 kcal) which is recovered as phosphate bond energy... 

The adenine nucleotides (AMP, ADP, and ATP) comprise a family of cofactors which are of prime importance in the transport of phosphate. The importance of phosphate as a means of transforming chemical potential and oxidation energy into metabolically active forms has been amply discussed by Lipmann and by Kalckar and others and needs no elaboration here. The major role of the adenine nucleotide system is the transport and storage of phosphate bond energy. 

Arnon, D. I., Whatley, F. R. and Allen, M. B. (1954) Photosynthesis by isolated chloroplasts. II. Photosynthetic phosphorylation, the conversion of light into phosphate bond energy. J. Am. Chem. 

This experiment told us some new things about arginine and urea synthesis (a) that half of the nitrogen of the urea molecule originated specifically in aspartic acid, (b) that fumarate was a product of the reaction and (c) that phosphate bond energy, specifically in the form of ATP, was required for the new carbon to nitrogen bond formed. 

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