Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 10

Protein Folding. In Chapter 2, we learned that a polypeptide in solution usually folds spontaneously into its proper three-dimensional shape. The driving force for this folding is the tendency to achieve the most favored thermodynamic conformation. A folded polypeptide can be induced to unfold (i.e., will undergo denaturation)if the solution is heated or made acidic or alkaline. The denatured polypeptide is a random structure, with many possible conformations.
(a)What is the sign of G for the folding process What about for the unfolding (denaturation)process How do you know
(b)What is the sign for S for the folding process What about for the unfolding (denaturation)process How do you know
(c)Will the contribution of S to the free energy change be positive or negative
(d)What are the main kinds of bonds and interactions that must be broken or disrupted if a folded polypeptide is to be unfolded Why do heat and extremes of pH cause unfolding