Cell Language Theory, The: Connecting Mind And Matter

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“6x9” b2861 The Cell Language Theory: Connecting Mind and Matter

site has assumed, through Brownian motions, its transient metastable con-

formation which is complementary to the shape of the ligand, in accord-

ance with the GFCP. The metastable (as indicated by the transition-state

Gibbs free energy surface denoted by dotted curves) conformation of the

active site before ligand binding is referred to as the virtual conformon

which is transformed into the real conformon when the ligand binds to it

stabilizing it and storing a part of the binding free energy as the conforma-

tional strains of the active site (see [14, pp. 27–30] and Section 3.4.4).

3.2.7 The GFCP and Translational Enzyme Catalysis

In passive ion transport, the ion selectivity is imparted by the structure of the

ion channel protein, but the direction of ion movement is determined by the

Gibbs free energy change, Equation (3.8), accompanying the ion movement:

        ∆GX = ∆GX° + 2.3 RT log[X]OUT/[X]IN, (3.8)

where ∆GX is the Gibbs free energy change accompanying the transport

of particle X (e.g., ions, anions, or neutral molecules) from inside to out-

side across a biomembrane. [X]OUT and [X]IN are, respectively, the concen-

tration of X outside and inside the system bounded by the membrane,

∆GX° is the standard Gibbs free energy change of X (i.e., ∆GX under the

standard condition where both [X]OUT and [X]IN are kept at 1 mol/liter at

pH at 7), R is the gas constant, and T is the temperature. Thus, when

[X] OUT < [X]IN, moving X out of the cell will tend to decrease ∆GX and

hence such movement will occur spontaneously. In contrast, when

[X]OUT > [X]IN, the opposite situation will prevail, i.e., it would be impos-

sible to move X out of the cell, unless some active process (i.e., free

energy dissipating process such as ATP-driven conformational change of

ion channel proteins) is involved (see Section 3.3.5).

A simplified representation of the mechanism of passive ion movement

across the cell membrane suggested by GFCP is depicted in Figure 3.10.

The ion channel protein (symbolized by the dotted square) is postulated to

have two ligand binding sites, each accessible from only one side of the

membrane (similar to the so-called “half-accessible ion channels” [151,

161–163], thus generating three channels (or gates) across the biological

membrane (to be denoted as upper, middle, and lower gates). Each gate is

assumed to have two conformational states — open and closed. The

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