Phosphate fixing power

Phosphate reacts and forms insoluble compounds with many metals, particularly iron, aluminum, and calcium. Under acid soil conditions, both iron and aluminum become more soluble, and thus as soil pH decreases, its phosphate fixing power increases. This means that iron and aluminum react with phosphate to form insoluble species that are not available to plants. Under basic conditions, high concentrations of calcium exist and insoluble calcium phosphates form. Insoluble phosphate species are also formed with other metals that happen to be present however, the three mentioned are generally present in the highest concentration, and so they represent the major reactants with phosphate. Iron, aluminum, and calcium phosphates can also occur as coatings on soil particles. 

Switching the system to zero potential for a fixed period of time within the time window bracketing the passage of the enzyme by the detector would allow for product accumulation. When the power is switched on again, the enzyme will be separated from the product and, if the product has suitable detection properties, it will appear as a peak on the enzyme plateau. This approach is sometimes referred to as parked reaction. A practical application featuring the activity assay of D-glucose-6-phosphate NADPH oxidore-ductase is shown in Figure 8.10. 

Formation of a sparming network of hydration water at the DNA surface upon hydration was studied by computer simulations [200,621] using the water drop methods [622, 623]. Simulations were carried out for a rigid dodecamer fragment of double-helical DNA. The structures of the canonical B-DNA and A-DNA [624] were fixed in space. The system involved 24 bases and 22 phosphate groups in two DNA strands surrounded by a mobile hydration shell of 22 Na ions and 24F water molecules. Evolution of the cluster size distribution ns on the surface of B-DNA upon increasing hydration is shown in Fig. 104. At low hydrations (F = 12, 13, and 14), ns shows deviations upward from the power law (19) at the intermediate cluster sizes S. At high hydrations (F = 17, 18, 19, and... 

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