Biosemiotics 257“6x9” b2861 The Cell Language Theory: Connecting Mind and Matter6.1.1 Molecular Machine
There are two kinds of machines — the so-called constrained equilibrium
machines (e.g., internal combustion engines) and molecular energy
machines or simply molecular machines (e.g., Na+/K+ ATPase) [227]. The
basic difference is that the former is composed of parts large enough to
resist thermal fluctuations (or Brownian motions), whereas the latter have
parts that are small enough to undergo thermal fluctuations [7, pp. 32–35].
Enzymes are molecular machines in that they manipulate free energy of
chemical reactions utilizing thermal energy (or Brownian motions)
through Franck–Condon mechanisms (see Figure 3.30), without violating
the Second Law (according to which no thermal energy can be converted
into useful work without a temperature gradient), and this manipulation is
thought to be guided by the genetic information encoded in their deform-
able structures.6.1.2 Dissipative Structures
Dissipative structures are dynamic structures (e.g., the flame of a candle
flame) that are maintained through a continuous dissipation of free energy
as heat. When a set of right chemical reactions is constrained by their
environment to interact in just the right way, dissipative structures are
formed (e.g., the Belousov–Zhabotinsky (BZ) reaction; intracellular cal-
cium ion gradients), which are characterized by chemical concentration
gradients in space (e.g., membrane potentials) or time (e.g., oscillating
chemical concentrations inside a cell). Dissipative structures formed
inside the living cell are referred to as IDSs (Section 3.2.1).6.1.3 Intracellular Dissipative Structures
IDSs are generated by coupling a set of enzyme-catalyzed chemical
reactions, just as sentences are formed by coupling a set of words
according to the rules of a grammar or texts are formed by coupling
sentences. Again, just as sentences and texts carry meaning, so do
dissipative structures, i.e., they have biological functions, such as trans-
mission of nerve impulses, chemotaxis, cell division, cell growth, gene
expressions, etc. (see Section 3.2.1).b2861_Ch-06.indd 257 17-10-2017 12:04:10 PM