Question

Use the thermodynamic arguement to explain why the perfectly folded protein is only marginally stable compared to its unfolded form.

Use the same equation to explain why higher temperatures denature proteins.

Which of the weak forces is the most important in the overall protein stability?

Answer 1

G=H-TS from chemistry now consider the transition from the folded to the unfolded state, with G the free energy chane for this unfolding process. Unfolding will only be spontaneous if G is negative . In this scenario, H will be positive because interactions in folded state are broken going to the unfolded state.S will also be positive because the unfolded state is more disordered.

Since H and S are both positive G will only be negative if TS>H. At low temperature, TS<H, meaning that G is positive and unfolding is not spontaneous. Increas the temperature TS>H where G will be negativesecondary protein structure stabilised by hydrogen bond all four weak forces contribute to the tertiary structure.Usually most importance force is hydrofhobic.