Element major biological

Be, and °Be. Radioisotopes of hydrogen and carbon are of particular interest because they are major biological elements, and thus can be used as both chemical and biological tracers. Recently, particle reactive Be = 53.3 day) has been utilized as a valuable coastal tracer of short-term particle deposition and remobilization. ... 

The metal ions of major biological significance are indicated in Figure 1, which shows part of the Periodic Table. Some information on the distribution and concentration levels of these metals in living systems is shown in Table 1. The transition metals and zinc are usually regarded as trace elements, as they are present in very small amounts. Of the transition elements, iron is the most abundant metal, and probably the most well studied. Iron is essential for all living systems with the exception of certain members of the lactic acid bacteria, which grow in environments notoriously low in iron, such as milk. Lactic acid bacteria are devoid of cytochromes, peroxidases... 

H. Matusiewicz, B. Golik, Determination of major and trace elements in biological materials by microwave induced plasma optical emission spectrometry (MIP-OES) following tetramethylammonium hydroxide (TMAH) solubilization, Microchem. J., 76 (2004), 23 D29. 

The early 1960 s saw the introduction of flame atomic absorption spectrometry (AAS) to clinical laboratories and this provided a sensitive yet simple analytical technique for the estimation of some trace elements in biological fluids. Trace elements is now perhaps an inaccurate description for those metals previously detectable in only small amounts when using older and less sensitive analytical techniques. Many such elements can now be estimated with precision and this has proved a great stimulus to trace-element research in clinical medicine. The number of trace elements known to be essential to man has doubled in the last twenty years [1]. Specific and treatable diseases are now known to be associated with excess or deficiency of trace elements and even in advanced societies dietary intake of some elements may be less than ideal [2]. Thus, monitoring of biological fluids for trace element levels in both health and disease can contribute towards major advances in nutritional management. 

Williams (150) has addressed this question in his 1981 Royal Society Bakerian Lecture on Natural Selection of the Chemical Elements. This describes how the biological selection of elements and their chemical properties are related. Williams has also given a detailed account (51) of the chemical basis of the uptake of elements by biological systems, and described (130) the chemistry that may occur in the specific case of aluminum. Based on this analysis he suggests a major problem with acid rain is the increased biological availability of aluminum. 

The atmosphere contains about 3.9 x lO tons of elemental nitrogen. Biological nitrogen fixation and production of NO in combustion and thunderstorms are the major natural sinks. Finally, NO deposits as HNO3 in rainwater. In the Haber process N2 fixes industrially. 

Major elements Major elements form constituents of biological molecules (C, N, O, P, S), ions either in... 

The dominant role of organic substrates in the binding of metals such as Cd and Cu is of particular relevance for the transfer of these elements into biological systems. It can be expected that even at relatively small percentages of organic substrates these materials are primarily involved in metabolic processes and thus may constitute the major carriers by which metals are transferred within the food chain. 

Ihnat M (1987) High reliability atomic absorption spectrometry of major and minor elements in biological materials. Fresenius J Anal Chem 326 739-741. 

Some of the difficulties in the unbiased determination of certain trace elements in biological materials may be due to problems of speciation. The range of complex organo-metallic species that can be found in nature is very wide (Frausto da Silva and Williams, 1991). In carrying out an analysis for a particular element in any type of biological fluid or tissues, major assumptions are made concerning the precise chemical composition of element species present. Different analytical techniques will have different sensitivities towards particular element species. Much of the early understanding of the special analytical problems posed by element speciation comes from studies of arsenic (Buchet et al., 1980 Buchet et al., 1981) and mercury (Clarkson, 1983). Problems with other metals remain to be resolved and may require considerable analytical sophistication such as in the analysis of chromium speciation (Urasa and Nam, 1989). 

The general involvement of the elements in biological systems is well documented and their biological function is now usually included in the majority of recent text books on inorganic chemistry. . ... 

This book provides an overview of the modem biogeochemical cycles of the essential elements for life. This chapter intends to introduce the reader to several aspects of the cycles of the major biological elements and the key transition metal ions on modem Earth as discussed in detail in the following chapters. 

The major biologically important molecules are formed primarily from 0 gen, carbon, hydrogen, and nitrogen. Some elements found in the body are crucial for life, although they are present in very tiny amounts (trace elements). Some of these trace elements include chromium, copper, fluorine, iodine, and selenium. 

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