Biologically important inorganics

ELDOR has been employed to study a number of systems such as inorganic compounds, organic compounds, biologically important compounds and glasses. The potential of ELDOR for studying slow molecular motions has been recognized by Freed and coworkers [29, 30]. 

A semi-permeable membrane, which is unequally permeable to different components and thus may show a potential difference across the membrane. In case (1), a diffusion potential occurs only if there is a difference in mobility between cation and anion. In case (2), we have to deal with the biologically important Donnan equilibrium e.g., a cell membrane may be permeable to small inorganic ions but impermeable to ions derived from high-molecular-weight proteins, so that across the membrane an osmotic pressure occurs in addition to a Donnan potential. The values concerned can be approximately calculated from the equations derived by Donnan35. In case (3), an intermediate situation, there is a combined effect of diffusion and the Donnan potential, so that its calculation becomes uncertain. 

Ion-exchange resins are cross-linked polymers which are typically polystyrene, cellulose or agarose based. Polystyrene is hydrophobic in nature and useful for inorganic ions and small molecules while cellulose and agarose are hydrophilic and more useful for the larger, biologically important molecules, e.g. proteins and nucleic acids, which either would be adversely affected by a hydrophobic environment or could not gain access to the small pore structure. 

Seawater studies require certified reference materials for biologically important dissolved components such as carbon (both inorganic and organic), nutrients, and trace metals, as well as for salinity, which is hydro-graphically important. A number of the committee s key recommendations therefore explicitly address these parameters. There is also a striking need for reference materials based on particulate matrices, where many of the analytical techniques used are matrix dependent and differ markedly... 

Lasalocid is the more disruptive polyether antibiotic to biological systems. This is due to its high tendency to dimerize and form complexes with biologically important divalent ions such as ("a and Mg ". Lasalocid exhibits a wide range of complexation affinities and transport capabilities, encompassing not only inorganic polyvalent ions but also primary amines and catecholamines (22). 

C. Singh (1964). Interactions between cationic and anionic compounds of biological importance with special reference to inorganic condensed phosphates and polymeric antibiotics. Ind. J. Chem., 2, 67-81. 

Phosphate minerals are found in rocks and living systems, and many biologically important molecules are phosphate esters (see Phosphorus Inorganic Chemistry). The balance between insoluble and soluble phosphates in the biosphere has been adversely affected by the use of phosphate fertilizers, water softeners and detergents. 

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