Biomolecules iron storage

In addition to being important in industry, transition metal ions play a vital role in living organisms. For example, complexes of iron provide for the transport and storage of oxygen, molybdenum and iron compounds are catalysts in nitrogen fixation, zinc is found in more than 150 biomolecules in humans, copper and iron play a crucial role in the respiratory cycle, and cobalt is found in essential biomolecules such as vitamin Bi2-... 

The mechanism by which lead affects the human body is extremely complex, as demonstrated by Landrigan and Needleman (1991) in Civil Action No. 87-2799-T, U.S. District Court for the District of Massachusetts in 1991. On an atomic level, lead has no biologic value and competes with metals that are essential to the human body, such as zinc, iron, and calcium. When lead inserts itself into the binding site of proteins, such as enzymes, in place of these essential metals, it distorts the biomolecules and their functions. For example, in certain membrane channels, lead occupies calcium s place, thereby blocking the flow of calcium within cells or across cell membranes. Since calcium is a very important regulator, this lead-calcium interaction affects memory storage and cell differentiation in the nervous system. 

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