Biology Reference
In-Depth Information
As indicated earlier, the terms e quilibrons and dissipatons have been coined
to represent the concepts of the equilibrium and dissipative structures, respec-
tively, that were formulated by I. Prigogine in the 1970s (Babloyantz 1986;
Prigogine 1977, 1980; Kondepudi and Prigogine 1998; Kondepudi 2008).
Equilibrons include DNA nucleotide sequences, and three-dimensional protein
structures that can exist without any dissipation of free energy, while dissipatons
include dynamic structures such as action potentials, intracellular gradients of all
kinds, including Ca ++ (Sawyer et al. 1985) and RNA gradients in space (L´cuyer
et al. 2007) and time (Garcia-Martinez et al. 2004), whose maintenance requires
continuous dissipation of free energy (Sect. 3.1 ). In addition, each network
contains two types of edges as indicated in Rows 2 and 4 in Table 10.3 . The
internal structure of the atom is held together by the forces acting on subatomic
particles through the mechanisms of exchanging gluons and photons, two of the
members of the family of bosons in quantum field theory (Han 1999; Oerter 2006).
The cellular analogs of these interactions in the atom are not yet known but two
possibilities have been suggested - conformons , mechanical strains of biopolymers
driving goal-directed molecular motions (Sect. 8) (Ji 1985a, 2000), and IDSs ,
cytoplasmic chemical concentration and mechanical stress gradients that integrate
molecular processes inside the cell (Sect. 9) (Ji 1991, 2002b). Conformons and
IDSs may be considered to be reifications of the cyton (also called the cell force )
(Ji 1991, pp. 95-118), just as photons and gluons can be viewed as reifications
of bosons (more on this in Fig. 10.4 ). The electronic transitions in atoms obey the
Franck-Condon principle (see Fig. 2.4 ). In (Ji 1974b, 1991), this principle was
generalized and applied to enzymic catalysis (see Row 6 in Table 10.3 ) (Sects.
2.2.3 , 7.1.3, and 8.2).
The last three rows in Table 10.3 exemplify those features and principles that
are distinct between the atom and the cell and hence do not belong to the ACIP set.
For example, under physiological conditions of temperature and pressure,
the atom acts as a closed thermodynamic system (being able to exchange energy
but not matter with its environment, except under very harsh conditions such as in
a nuclear reactor), while the cell acts as an open system (able to exchange not only
energy but also matter with its environment) (Sect. 2.1 ) . In part because of this
thermodynamic difference, the edges in the atomic network are fixed and unable
to change, while those of the cell are dynamic and able to form or dissolve
wherever (space) and whenever (time) needed by the cell, driven by the free
energy of chemical reactions catalyzed by intracellular enzymes. For this reason,
we can refer to the atomic network as passive and the network constituting
the cell as active (see Row 9 in Table 10.3 ). The time- and space-dependent
intracellular network conceptualized here can also be viewed as a renormalizable
network in the sense that the cell is capable of reorganizing or regrouping
its nodes to realize different functions in response to environmental inputs
(Sect. 2.4 ) and cells themselves can become nodes of multicellular systems such
as the brain.
It is truly amazing to find that there apparently exists a set of common principles
and features that are operative in two material systems whose linear dimensions
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