Transport of iron

Where small quantities of high-purity steam is required for electronic chip, pharmaceutical, sterilization, food preparation, and similar process applications, a small risk of steam contamination may exist. This may be caused directly by the use of amine treatments or indirectly through process contaminants or the transport of iron oxides. Consequently, alternative arrangements for steam generation are made. 

The transport of iron oxides throughout the system is a very noticeable effect resulting from less than fully optimized chemical treatment programs and associated control parameters in high-pressure boilers. 

The atmosphere may be an important transport medium for many other trace elements. Lead and other metals associated with industrial activity are found in remote ice caps and sediments. The transport of iron in wind-blown soil may provide this nutrient to remote marine areas. There may be phosphorus in the form of phosphine, PH3, although the detection of volatile phosphorus has not been convincingly or extensively reported to date. 

S. B. Pandeya, A. K. Singh, and P. Dhar, Influence of fulvic acid on transport of iron in soils and uptake by paddy seedlings. Plant Soil I98 17 (1998). 

It should be stressed that in the RPE transport of iron ions between the photoreceptors and choroidal blood supply is constantly occurring (He et al., 2007 Wong et al., 2007). Iron is essential for the proper function and survival of every cell as it serves as a co-factor for vital mitochondrial enzymes. 

Sla (Anderson Transport of iron sla mice (Manis, 1971 Iron-deficiency anaemia ... 

IREG1 (McKie et al., 2000) Transport of iron across intestinal basolateral membrane 7 Iron-deficiency anaemia... 

One paradigm for membrane transport of iron is the binding of the receptor protein to an iron-free siderophore molecule, followed by exchange of iron from an external ferri-siderophore to the receptor bound iron-free siderophore, and subsequent transfer across the cellular membrane. This shuttle mechanism has been explored in the transport system of ferric pyoverdine in P. aeruginosa (215,216). It is unclear why the bacterial system behaves in this manner, but mutagenesis studies of the protein suggest that residues involved in the closure of the P-barrel will not interact in the same way with the iron-free siderophore as they do with the ferri-siderophore. A similar mechanism has been suggested for A hydrophila and E. coli (182). 

Binding and Transport of Iron-Porphyrins by Hemopexin WilliamT. Morgan and Ann Smith... 

Koster, W. (1997). Transport of iron(III) hydroxamates across the cytoplasmic membrane of Escherichia coli. In Bioinorganic Chemistry, Transition Metals in Biology and their Coordination Chemistry, ed. Trautwein, A. X., Wiley-YCH, pp. 56-68. 

Braun, V. and Braun, M. (2002). Active transport of iron and siderophore antibiotics, Curr. Opin. Microbiol., 5, 194-201. 

The acquisition of iron in plant roots has been described in Chapter 7. Once in the apoplast of the root, the iron must be transported through the roots to the xylem and thence to the leaves. In order to ensure that the iron does not precipitate or generate oxygen radicals during its transport, the iron is bound to an intracellular transporter of iron (both Fe2+and Fe3+),... 

Most of the naturally occurring chelating agents are substituted hydroxamates which are produced by a variety of protista so that iron(III) subsequently becomes available for biochemical processes. Neilands (73) has suggested that the hydroxamates facilitate the transport of iron across cell membranes. The distribution of hydroxamates in the biosphere appears limited. However, if there was a wider distribution of hydroxamates in the environment then the management of actinide wastes could become a problem of horrifying dimensions if these chelators facilitated the transport of actinides across cell membranes. 

Criss RE (1999) Principles of stable isotope distribution. Oxford Univ Press, New York Croal LR, Johnson CM, Beard BL, Newman DK (2004) Iron isotope fractionation by anoxygenic Fe(II)-phototrophic bacteria. Geochim Cosmochim Acta in press Duce RA, Tindale NW (1991) Atmospheric transport of iron and its deposition in the ocean. Limnol... 

This loss is compensated by the alimentation. 70 % of the body iron is contained in hemoglobin. Transferrin ensures the transport of iron, while ferritin and hemosiderin are used for the storage of iron in a non-toxic form ferritin is indeed able to transform the highly toxic Fe(II) in to the less toxic Fe(III). 

---