Multicellular Systems - Molecular Theory of the Living Cell - page 559

Just as the FDTABIM is needed for the upward causation because the force originates at the
molecular level in muscle cells and is finally needed at the macroscopic skeletal muscle
level (Fig. 15.19 ), so it may be that the FDTABIM is needed for the downward causation
because the control information originates at the molecular level in cortical neurons and the
final control information is needed at the level of the macroscopic cortical regions
(Fig. 15.20 ). (15.41)
Statement 15.41 seems reasonable in view of the facts (1) that, just as force
generation requires free energy, so does decision making (also called reasoning ,
computation ,or selecting between 0 and 1, between polarization and depolariza-
tion ), and (2) that free energy is available only from enzyme-catalyzed chemical
reactions or membrane depolarization (i.e., collapsing ion gradients) occurring at
the ion channel level.
aa Enzymes are molecular machines that are driven by chemical reactions that
they catalyze. So the operation of an enzyme can be represented as a trajectory in a
phase space (van Gelder and Porter 1995, p. 7) which would collapse when free
energy supply is blocked. Therefore, an enzyme in action is a dissipative structure
or a dissipation and hence can be named as an X-ator, X being the name of the city
where the most important research has been done to establish the mechanism of
action of the dissipative structure under consideration. In the case of enzymology,
there are three research groups, in my opinion, that have made major contributions
to advancing our knowledge on how enzymes work - (1) S. Xie (2001) and his
group then at the Pacific Northwest National Laboratory, Richland , WA (by
measuring the single-molecule enzymic activity of cholesterol oxidase analyzed
in Sect. 11.3 ), (2) Rufus Lumry (1974, 2009) and his group at the University of
Minnesota at Minneapolis (for establishing the role of mechanical processes
in enzymic catalysis), and (3) William Jencks (1975) at the Brandies University
in Waltham , MA, for establishing the fundamental role of the substrate binding
processes in enzymic catalysis which he referred to as the Circe effect . To acknowl-
edge the contributions made by these three groups, enzymes have been named as
RMWators in this topic (see Fig. 15.16 ).