.....for I am fearfully and wonderfully made:
Psalm 139:14
* "Consider the element carbon (C)—the most unique element of all the chemical elements in the Periodic Table. It is a nonmetal having unlimited capacity to participate in every known type of covalent chemical bonding (i.e., pairs of electrons shared between atoms) which unite atoms of the same kind to each other and to other kinds of atoms as well. This feature, called catenation, is virtually unlimited only for the element carbon, making possible the wide diversity of organic molecules needed for life. * Other elements, such as silicon (Si), nitrogen (N), sulfur (S), phosphorus (P), etc., display some very limited capacities for catenation, but do not even come close to rivaling the catenation ability of C. Without this unique feature, the formation of such essential biomolecules as proteins, DNA (deoxyribonucleic acid), RNA (ribonucleic acid), cellulose, etc., would be impossible.
Elements such as carbon (C), nitrogen (O), sulfur (S), phosphorus (P), and other nonmetals are called
Representative or Main Group Elements.
With the exception of oxygen, atoms of these elements are stable only when even numbers of their electrons unite in pairs; otherwise the presence of "unpaired" electrons impart chemical instability.
On the other hand, metallic elements such as chromium (Cr), iron (Fe), nickel (Ni), etc., called Transition Metals, are among the Sub-Group Elements and do contain unpaired electrons, but surprisingly are chemically very stable.
The element oxygen (O) exists freely in nature as the gaseous diatomic molecule O2. No substitute for oxygen exists which is similarly utilized in life processes. There are other Representative Elements which also occur as free diatomic molecules, e.g., hydrogen (H2), nitrogen (N2), fluorine (F2), and chlorine (Cl2). However, O2 is the only molecule of this type possessing two unpaired electrons; the others all have paired electrons. In spite of this, O2 is still chemically stable. This singular notable exception to the electron-pair rule of stability for Representative Elements has no known explanation.
* Furthermore, if it were not for the two unpaired electrons in O2, it would not be capable of binding to the iron (Fe) atoms in hemoglobin, with precisely the amount of energy needed to carry the O2 into the bloodstream and then release it. Some other molecules such as CO and NO can replace O2 in binding to hemoglobin, but they completely destroy the hemoglobin function.
Furthermore, in cytochrome oxidase, O2 reacts specifically with electrons produced via an oxidation/reduction coupling mechanism between iron (Fe3+) and copper (Cu2+), whereby these are reduced to Fe2+ and Cu+ respectively, and again reoxidized to Fe3+ and Cu2+. This process occurs in cycles during the mechanism of O2 binding to iron in hemoglobin. No other substitutes for these two elements in this process exists. Life's requirements are precise.
* The element zinc (Zn) is crucial in the formation of so called zinc "finger" proteins, in which Zn2+ is bonded to pairs of cysteine and histidine amino acids, acting like "fingers" which interact with specific gene segments.
Such characteristics defy the probability that any random evolutionary process could account for such specificity in design, attributable only to the Creator, God." ICR