The Elements in Biology

Isotopes Indicate Ancient Life Forms and Climate Changes 

The common element of oxygen has eight protons and eight neutrons. A stable isotope with two additional neutrons is also relatively common. Because water-containing lsO evaporates more slowly and condenses more rapidly, the ratio of 180/160 in Antarctic ice cores indicates major climate shifts since early in geologic time. Increased lsO indicates a sudden warming, and increased lsO indicates a sudden cooling. 

1 Necessary Basics Elements, Isotopes, Ions, Chemical Reactions, Energy Metabolism, and Bacterial Structures 

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Advances in selenium biochemistry (Arthur, 1994 Heider and Boeck, 1994 Foster and Sumar, 1997 Patching and Gardiner, 1999) and methods for the determination and speciation of the element in biological and environmental samples (Pyrzynska, 1996 D Ullivo, 1997 Thomson, 1998) have been reviewed. In this section, a brief overview of more recent developments in analytical methods and their application to the study of selenium-containing species in biological materials is provided. 

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. . ... 

Distributions of the elements in biological fluids, cells, organs, etc. 

Chemical speciation of the elements in biological samples and systems... 

We tend to think of metals as lustrous solids copper, tin, gold, silver, iron. We are less likely to think of individual metal atoms in biological machines. Nevertheless, plants and animals require the presence of tiny amounts of transition metals. Humans require most of the elements in the first transition metal series and at least one element from the second transition metal series, molybdenum. 

Byrne AR, Deemelj M, Kosta L, and Tusek-Znidaric M (1984) Radiochemical neutron activation analysis in standardization of trace elements in biological reference materials at the nanogram level. Mikrochim Acta [Wien] 1 119-126. 

Mavrodineanu R, ed. 1977) Procedures Used at the National Bureau of Standards to Determine Selected Trace Elements in Biological and Botanical Materials. National Bureau of Standards Spec Publ 492. National Bureau of Standards, Washington, DC. 

Taylor A (1996) Reference materials and analytical standards to stimulate improved laboratory performance Experience from the external quality assessment scheme for trace elements in biological samples. Mikrochim Acta 123 251-260. 

Aluminium is the most abundant element of the lithosphere. Although a large number of persons are exposed world-wide to Al, the incidence of pulmonary effects is low (Schaller et al. 1994). In the 1970 s the effect of Al appearing in dialysis solutions on the central nervous system has become weU known. Increased Al could also be detected in several brain regions of patients with Alzheimer s disease. For the determination in biological materials the most widely used method is GF-AAS. 

IAEA (1985) [Muramai SU Y, Parr RM] Survey of currently available reference materials for use in connection with the determination of trace elements in biological and environmental materials. Report IAEA/RL/128, International Atomic Energy Agency, Vienna, Austria. 

Horikoshi T, Nakajima A, Sakaguchi T. 1981. Studies on the accumulation of heavy metal elements in biological systems. XIX. Accumulation of uranium by microorganisms. Eur J Appl Microbiol Biotechnol... 

Williams JC Memphis State University, Memphis, TN Develop and improve quantitative methods for the determination of both metal and nonmetal elements in biological samples National Institute of General Medical Science... 

The Functional Value of the Elements in Organisms Introduction to Biological Compounds... 

Most metals, for which compounds are carcinogenic, are from IV group of Periodic Table of Elements. In biological systems, carcinogenic metals can form stable complexes and biological availability of these complexes determines the carcinogenic potential of various metal compounds. 

It is often assumed that if something is in the soil, it will be in plants. This is incorrect. Plants do not take up all of the elements or molecules present in their immediate environment. However, there are some plants, called hyperaccumulators, that accumulate higher than normal levels of some toxic elements. These plants still do not take up all the elements in their environment and they are often small, so the total amount of toxic elements removed from soil is limited. In addition, not all species of an element are toxic and some are not biologically available and thus do not enter biological systems. For example, chromium as Cr(VI) is more toxic and more biologically available than is Cr(IH) [1]. 

It is intriguing that Mo is an important element in biology despite its scarcity at the Earth s surface—indeed, no element of similar scarcity is so biochemically ubiquitous. The reason for this paradoxical combination is unknown. Possible explanations include the unique chemical character of this element, evolutionary adaptation to the abrmdance of Mo in oxygenated oceans relative to other transition metals, a legacy of prebiotic chemical evolution in Mo-rich environments (e.g., in association with sulfide minerals), or some combination of these factors. Regardless, this paradox has inspired creative hypotheses about the importance of Mo in evolution (Crick and Orgel 1973 Anbar and Knoll 2002). 

Iron is one of the most important elements in biology. In hemoglobin, it allows the binding of molecular oxygen. Iron plays an important role in the active centers of many enzymes. The total quantity of iron in the human body is about 4g. Each day, the body eliminates approximately 1 or 2 mg of iron. 

A comparison of automated pipetting with manual pipetting, by Weltz [16]. demonstrates a difference of approximately one order of magnitude 0.4% RSD for automatic sample introduction versus 3.2% RSD for manual sample introduction. To achieve optimum results for trace elements in biological materials, the use of dedicated automated samplers is recommended. The Hquid-handhng capabihties of a pipetter/diluter workstation have been evaluated at Ortho Pharmaceutical (Haller et al. [17]). Four different volumes of each of three solvents were dispensed 20 times. Actual volumes... 

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