Fe2+ conversion from Fe 3+ enzyme responsible is?
I. Most of the iron in the diet is in the ferric (Fe3+) form, whereas it is the ferrous (Fe 2+) form that is absorbed. Fe3+ reductase activity is associated with the iron transporter in the brush borders of the enterocytes .
II. Gastric secretions dissolve the iron and permit it to form soluble complexes with ascorbic acid and other substances that aid its reduction to the Fe 2+ form.
III. The importance of this function in humans is indicated by the fact that iron deficiency anemia is a troublesome and relatively frequent complication of partial gastrectomy.
IV. Almost all iron absorption occurs in the duodenum. Transport of Fe 2+ into the enterocytes occurs via divalent metal transporter 1 (DMT1).