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can be derived from, the other) but necessary for a complete description of motions
of material objects, as illustrated below using DNA. Type II complementarity will
be referred to as the Bohrian or physical complementarity .
Type III complementary pairs satisfy all of the three logical criteria of complemen-
tarity. As evident in the last row of Table 2.12 , all of the examples given for Type III
complementarity derive from philosophy because of the transcendentality criterion
playing an important role. The transcendentality criterion entails invoking the two
levels of reality that transcends each other - for example, the epistemological level
where the complementary pair, AandB, hasmeanings and the ontological level, C, that
transcends the epistemological level. In some cases, Cmay exist in the same level as A
and B, for example, the triad of father (A), mother (B), and a child (C). We may refer to
such cases as representing the Type III 0 complementarity as compared to Type III.
The complementarity between the Watson-Crick base pairs (i.e., AT and GC)
has been known since the helical structure of DNA duplex was discovered by
Watson and Crick in 1953. About a decade later, it was discovered that the linear
arrangements of three nucleotides along the long axis of a DNA strand encoded
amino acids and the strings of nucleotide triplets in turn encoded genetic informa-
tion specifying the structure of proteins.
The natural question that now arises is to which type of complementarity does the
Watson-Crick base pairs belong? To answer this question, we must ask three related
questions. (1) Do Watson-Crick base pairs satisfy the Exclusivity criterion? In other
words, are the Watson-Crick base pairs mutually exclusive? The answer must be
Yes, since these molecular pairs are distinct and mutually irreplaceable. (2) Do the
Watson-Crick base pairs satisfy the Essentiality criterion? In other words, is there a
third term C for which the Watson-Crick pairs are essential? Again the answer
seems to be Yes, since without these base pairs, molecular copying (i.e., information
transfer from one nucleic acid to another) would be impossible. (3) What is the third
term that transcends the level of Watson-Crick base pairs and yet serves as their
ground or source? One plausible answer seems to that the C term is the living cell, for
the replication of which the Watson-Crick base pairs are essential and without
which no Watson-Crick base pair can exists. Based on these answers, it may be
concluded that the Watson-Crick base pairs exhibit Type III complementarity.
The above considerations are almost exclusively focused on the information
aspects of life - complementary shapes of base pairs, nucleotide triplets, nucleotide
sequences encoding genetic information, etc. Important as these aspects of life are,
they alone are incomplete to account for the dynamics of life, since the utilization of
genetic information encoded in DNA requires expending requisite free energy
derived from chemical reactions catalyzed by enzymes. In other words, the energy
aspect of DNA must be explicated along with the information aspect. Indeed, it can
be stated that DNA carries not only genetic information but also mechanical energy,
as evident in the formation of DNA supercoils catalyzed by ATP-driven
topoisomerases and DNA gyrases (Sect. 8.3 ). Therefore, it can be asserted that
the DNA duplex molecule embodies the information-energy complementarity that
satisfies (1) Exclusivity (genetic information and mechanical energy are mutually
exclusive), (2) Essentiality (genetic information and mechanical energy are both
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