Answers
##### Answer and Explanation #####
All of us know very well that there are numbers of the elements present in our body, and all of them play their significant role in different biological pathways , but it may vary the uses of their quantity , more , less or very less , hence named Major (i.e C,N,H, O, P, S etc), Trace (i.e Cu, I, Fe, Zn etc) and Ultra trace (Cr, F, Li , V etc.) respectively.
Here according to the question we are discussing a trace element i.e. Iron (Fe) which is one of the most important trace element useful in human biological system. Iron is element that is the constituent of human blood known as heme protein of Hemoglobin, which performs, oxygen transport in our body system with the help of tissue know as blood (red in color).
Mainly Iron is present in Fe2+ (Ferrous ions) and Fe3+ (Ferric Ion) in our body Since ferric ion is poorly soluble near neutral pH , hence Iron is absorbed in the form of complexes.
The storage of regulation occurs after the up taking in human cell. In this regulation a protein Transferrin plays its crucial role by binding with iron ions which are absorbed from duodenum, then these are carried in the blood to the cells. Mainly transferrin traps Fe3+ as stabilizing complex and transported , as it reaches bone marrow Transferrin is reduces Fe3+ state to F2+ and stored as ferritin to incorporate with hemoglobin.
Apart from this hemoglobin this heme protein assists in various forms like Myoglobin (storage of Oxygen transport), and Cytochrome P450 ( Helps in Electron transport chain, in the respiration),
As above we have seen that Iron plays roles in different types of biological function, and it shows ionic forms to play different biochemical processes.
Thanks
.