Free energy lowest specific

Natural proteins are able to fold to specific structures because, on average, native-like interactions between residues are more stable than non-native ones. The former are therefore more persistent and the polypeptide chain is able to find its lowest energy structure by a process of trial and error. Moreover, if the free energy surface or landscape has the right shape (see Fig. 13.1), only a minute fraction of all possible conformations is sampled by any given... 

The typical protein sequence contains a large number of hydrophobic amino acids. When these amino acids reach a specific concentration the protein collapses into a globular conformation, similar to the critical micellar concentration of detergents. This state is the result of a collapse of the protein driven by the minimization of the interaction of the hydrophobic amino acids with the aqueous environment. This condensed state is fluid in that the polymer is not in one well-defined conformation but sampling many different conformations until eventually the native conformation with the lowest free energy is found. This, usually ill-defined, state is referred to as the molten globular state. The manner in which... 

In case of renewable plants relying on a free energy souree (like sun, wind, waterfall besides salinity gradient), the lowest eost of the electricity is generally obtained in correspondence to die minimum specific plant cost. 

FIGURE 5.10 Schematic showing the relationship between internal energy E and free energy G of three polymorphic forms 3 > E2 > 1 and S3 > S2 > S. The form with the lowest G will be the one usually found at a specific temperature. 

In the previous chapter, we discussed liquid polymer systems. These exist in specific states selected by the laws of equilibrium thermodynamics. The rules which control structure formation during crystallization are different and this is a most important point to be noticed Structure formation here is governed by kinetical criteria rather than by equilibrium thermodynamics. What does this mean Indeed, we encounter here a new criterion The structure which develops at a given temperature is that with the maximum growth rate rather than that with the lowest free energy. As a consequence, treatment of the crystallization behavior of polymers requires kinetical considerations. 

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