Feedback for Multiple Choice Quiz 7

  All of the correct answers have a green check mark.
  Incorrect answers have the "red-lit" button next to your choice.
  1. In other words, exergonic processes are spontaneous.

  2. See pg 414 in Campbells for a definition of standard states.

  3. lnK=2.3log10K. Therefore DG= -2.3RTlog10K. From this equation it is apparent that a 10 fold change in K translates into a -2.3RT(log1010) or -2.3RT change in DG.

  4. The correct answer follows from one of the important expressions for free energy:
    DG = DH - TDS

  5. Since the Standard Gibbs free energy is positive the products must be at a higher energy level, thus the reactants will be favored. You can also see this by calculating the equilbrium constant. The equilibrium constant will be less than 1, thus the reactants will be favored.

  6. A positive and a negative charge on a molecule is always more favorable than either alone. Try to rewrite the question (and correct answer) from the perspective of the carboxyl group affecting the amino group ionization.

  7. Standard states are a matter of definition or "convention"; this is one of the important ones. The incorrect statements are all "extremely false".

  8. Denaturation will disrupt the non-covalent interactions that mediate secondary, tertiary and quaternary structure, but not the covalent bonds that comprise the primary structure of the protein.

  9. At Tm, the midpoint of a cooperative unfolding reaction, each of the four statements imply the other three.