Sinopsis
Living organisms store and transport transition metals both to provide appropriate concentrations of them for use in metalloproteins or cofactors and to protect themselves against the toxic effects of metal excesses; metalloproteins and metal cofactors are found in plants, animals, and microorganisms. The normal concentration range for each metal in biological systems is narrow, with both deficiencies and excesses causing pathological changes. In multicellular organisms, composed of a variety of specialized cell types, the storage of transition metals and the synthesis of the transporter molecules are not carried out by all types of cells, but rather by specific cells that specialize in these tasks. The form of the metals is always ionic, but the oxidation state can vary, depending on biological needs. Transition metals for which biological storage and transport are significant are, in order of decreasing abundance in living organisms: iron, zinc, copper, molybdenum, cobalt, chromium, vanadium, and nickel. Although zinc is not strictly a transition metal, it shares many bioinorganic properties with transition metals and is considered with them in this chapter. Knowledge of iron storage and transport is more complete than for any other metal in the group.
Content
- Transition-Metal Storage, Transport, and Biomineralization
- The Reaction Pathways of Zinc Enzymes and Related Biological Catalysts
- Calcium in Biological Systems
- Biological and Synthetic Dioxygen Carriers
- Dioxygen Reactions
- Electron Transfer
- Ferredoxins, Hydrogenases, and Nitrogenases: Metal-Sulfide Proteins
- Metal/Nucleic-Acid Interactions
- Metals in Medicine
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