Concentration phosphate group effect

A basic scientific investigation of fire retardancy, however, remained to be initiated by Gay-Lussac in France at the request of King Louis XVIII in 1821 who was again interested in reducing the flammability of theater curtains. This researcher noted that the ammonium salts of sulfuric, hydrochloric and phosphoric acids were very effective fire retardants on hemp and linen and that the effect could be improved considerably by using mixtures of ammonium chloride, ammonium phosphate and borax. This work has withstood the test of time and remains valid to this day. Thus the basic elements of modern fire retardant chemistry had been defined early in recorded history and remained the state of the art until early in the twentieth century. The most effective treatments for cellulosic materials being concentrated in Groups III, V and VII elements. 

The main drawback of the DHAP-dependent aldolases is their strict specificity for the donor substrate. Apart from the scope limitation that this fact represents, DHAP is expensive to be used stoichiometrically in high-scale synthesis, and labile at neutral and basic pH, and therefore its effective concentration decreases over time in enzymatic reaction media, hindering the overall yield of the aldol reaction. In addition, due to the presence of a phosphate group in both DHAP and the... 

Overall, the effects of polycations on the helix-coil transition of DNA are similar to those exhibited by the small cations both of them induce thermal stabilization of DNA duplex and decrease the cooperativity of the helix-coil transition In both cases the reasons for the stabilization effects are the screening of the negatively charged phosphate groups of the DNA, which reduces their electrostatic repulsion (Schildkraut, 1965). However, the effective concentration of a simple salt at which the same stabilization effect is achieved is ca. 103 times higher than the effective concentrations of a polycation. Consequently, polycations provide for a much more efficient screening of the DNA phosphate groups than the small cations. 

In the above equation, SPC is the total intensity (peak area) of signals from the middle phosphate groups, SPst is the standard P, signal intensity, and C is the PolyP concentration, expressed in mg P, per ml. The effect of reduction of the contribution of inner phosphate groups to the total intensity of the Pc signals is obviously associated with the primary and secondary structures of PolyPs. 

Coenzymes are usually more complex molecules than activators, although smaller molecules than the enzyme proteins themselves. Some compounds, such as the dinucleotides NAD and NADP, are classified as coenzymes and are specific substrates in two-substrate reactions. Their effect on the rate of reaction follows the Michaelis-Menten pattern of dependence on substrate concentration. The structures of these two coenzymes are identical except for the presence of an additional phosphate group in NADP nevertheless, individual dehydrogenases, for which these coenzymes are substrates, are predominantly or even absolutely specific for one or the other form. 

At this pH, the phosphotriesters formed mainly lose alcohol to re-form the phosphodiester, but at higher pH, hydrolysis with chain scission takes place. Alkylation also proceeds at nucleophilic centres on the base and sugar moieties, and the modification likely to cause most damage in vivo has not been defined. Studies involving aflatoxin Bi and benzanthracene derivatives have tended to concentrate on the modification of the bases, to the exclusion of possible effects at the phosphate group, but there is good evidence that the latter should not be ignored. ... 

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