Further Transport of Metal Ions Inside Plants

For any of these organisms, delivery of ligands to soil or groundwater which then sequester metal ions (both essential and non-essential) requires decoupling of matter from some metabolic cycle. In simple cases, like with green plants, there is no demand for additional reactants to produce the corresponding ligands, as citrate or malate are taken from the tricarboxylate cycle directly. More generally speaking, however, formation of such extracellularly active ligands takes additional reactants...

Rules Which Can Account for Selective Metal Ligand Interactions

There are two classical rules which predict what kind of ligand will be bound more tightly to a given metal ion (or atom). The older one, by Ahrland et al. (1958), forms different classes of metal ions according to the kinds of atoms they prefer to bind to - here considering only the atom directly adjacent to the metal, regardless of its own atomic environment besides the metal ion. For example, all nitrogen donors, such as nitrite, ammonia, pyridine or nitriles, are treated to be identical and...

Equilibrium Models Concentration Ranges and Biological Functions of Metal Ions

Although equilibrium models will provide realistic representations of distributions of most chemical elements these are unlikely to hold for such metals which both have a number of biochemical functions and bind strongly to the various ligand sites of biomasses, in addition to being rather abundant in the environment such as Cu . It can be estimated that free i.e., just aquated Cu2 or Zn2 ions will occur in plant sap at femtomolar or even lower concentrations at best, leaving their transport to...