2. A Theory of Energy Transmission 



It often happens that, unconsciously, our thinking becomes 

 dominated by certain pictures which we have met too often to 

 question their correctness. In my opinion, our difficulty in ap- 

 proaching the problem of energy transformation in muscle is due 

 to our having been misled by the formalism of our thermodynamic 

 bookkeeping. When making up the energy balance sheets of re- 

 actions we usually express both the "potential energy" of a bond 

 and the kinetic forms of energy in calories and so, unconsciously, 

 accept their identity. But there is a very great difference between 

 the two, at least in their biological activity, which we can illustrate 

 by comparing it with the difference between sitting on top of an 

 atomic bomb while its potential is a potential, its bonds are bonds, 

 and its energy is locked up inside its atoms, and then trying to 

 remain sitting on it when these bonds are exchanging their poten- 

 tial for more active, kinetic forms of energy. Though mechanics 

 may find both forms of energy essentially identical we will sense 

 a very considerable difference in their biological activity. The situa- 

 tion with the "energy" of the -^P is analogous to that of the 

 A-bomb. While its energy is enclosed in the bonds of the molecule 

 as a potential, it can be expected to have no outward action (except 

 showing a little extra weight which we could find if our balances 

 were more sensitive ) . This bond energy may be transferred, as 

 such, from molecule to molecule and from bond to bond in the 

 group transfer reactions of our intermediary metabolism. But if 

 this potential has to go into biological action, produce work or 

 motion, an analogy to the A-bomb, it might be exchanged for 

 more active and mobile forms of energy. Such active and mobile 

 forms of energy, on the molecular level, could hardly be anything 



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