Page 242 - The Miracle in the Cell Membrane

forms, it is not expelled from the body. A
loss of iron from the body takes place only
through such processes as bleeding, cell
renewal and transport of iron to the devel-
oping fetus. 80
Iron is a vital micronutrient, an insep-
arable component of hemoglobin and
essential to the transport of oxygen and
carbon dioxide in the blood. The biologist
draws attention to the importance of iron:
Of all the metals, there is none more essential
to life than iron. It is iron which by its deli-
cate association with oxygen in the hemoglo-
bin in human blood is able to convey in sub-
dued form this most ferociously reactive of
atoms, the precious giver of energy, to the
respiratory machinery of the cell. Without
the iron atom, there would be no carbon-
based life. The intriguing and intimate rela-
tionship between life and iron, between the
red color of blood and the dying of some dis-
tant star, not only indicates the relevance of
metals to biology but also the biocentricity of
the cosmos. No other metal atom could exact-
ly mimic the properties of iron in heme. None
of the other transitional metal atoms closely
related to iron will substitute for iron in
hemoglobin, because none are of precisely the
same size, nor do any possess precisely the
same chemical characteristics allowing them

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