Chemistry - Molecular Theory of the Living Cell - page 75

Physics

Biology =

Chemistry Evolution

Fig. 3.4 Biology as the triadic science of physics , chemistry , and evolution (or history ). Physics is
viewed as the study primarily of material objects themselves (e.g., three-dimensional structures of
matter), chemistry as the study of material transformations from one kind to another (i.e., chemical
reactions), and biology as the study of those processes and structures that have been selected by the
biological evolution (e.g., metabolic networks, the cell cycle, morphogenesis)

shown in Fig. 3.4 . One unexpected consequence of Fig. 3.4 is the emergence of the
fundamental role of biological evolution as the mechanism that selects those
chemical reactions and physical processes that contribute to the phenomenon
of life.

3.1.6 Four Classes of Structures in Nature

As discussed in Sect. 3.1 , Prigogine (1917-2003) divides all structures in the
Universe into equilibrium (e.g., rocks, three-dimensional structures of proteins,
amino acid sequences of proteins, nucleotide sequences of DNA and RNA) and
dissipative (e.g., flames, concentration gradients, DNA supercoils) structures. It
appears that Prigogine's classification of structures into equilibrium and dissipative
structures is based on dynamics , the study of the causes of motions, namely, the
energies and forces causing motions. Since the science of mechanics comprises
dynamics and kinematics that are complementary to each other (see Sect. 2.3.5 )
according to Bohr (Murdoch 1987; Plotnitsky 2006), it may be logical to classify
structures into two groups based on kinematics as well. Kinematics is defined as the
study of the space and time coordinations of moving objects without regarding their
causes. In contrast to the classification of structures into equilibrium and dissipative
structures based on dynamics, it is here suggested that the two divisions of structures
based on kinematics are (1) local and (2) global motions, including the division into
microscopic and macroscopic motions. Therefore, the structures of the Universe can
be divided into four distinct classes based on the kinematics-dynamics complemen-
tarity - (1) local equilibrons , (2) global equilibrons , (3) local dissipatons , and (4)
global dissipatons as summarized in Table 3.2 with specific examples given for each
class. Several points emerge from Table 3.2 . First, equilibrons (equilibrium
structures) can be identified with “thermal motions” or “random motions,” which
entail no dissipation of free energy, while dissipatons (dissipative structures) can be
identified with “directed motions” or “non-random motions,” which entail free