Energy conservation controls, influence

Fig. 3. These diagrams (A, B) are intended to illustrate the regulation and operation of these mitochondrial fatty acid synthetic systems using a hydrodynamic analogy. Electron pressure and flow are depicted as fluid pressure and flow under gravitational influence. Electron flow down the electron transport chain is ultimately controlled by (ADP Pi) ATP ratio. When the latter ratio is high (A, left) electron flow rate is maximal and the steady-state NADHiNAD" ratio is low (State 3 Chance and Williams, 1956), On the other hand, (B, right) when either the (ADP + P,) ATP ratio is low or oxygen is lacking, substrate reduces NAD+ faster than it can be oxidized. The elevated NADHiNAD ratio reverses the usual flow of electrons from fatty acid oxidation. Acetate now becomes incorporated into fatty acids with the consequent oxidation of NADH and, therefore, perhaps permits some ATP to be synthesized via other substrate-level energy conserving steps.

The concentrations of defects is controlled by a set of coupled equations, mass action laws and laws of conservation, as illustrated in section 11.1.2, and [D] is most often activated thermally. Consequently, the activation energy of ionic conductivity is the sum of two contributions, a transport term and a term reflecting the influence of temperature on the concentration of defects. A change of slope in a diagram Log (ctT)-1/T (see Figure 11.10) indicates a change in the defect regime. 

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