AP Science Practice Question A particular enzyme has an optimal temperature of 37°C and begins to denature at 45°C. During
denaturation, entropy increases (the protein loses much of its organization). The protein also
increases its energy content (energy must be absorbed from the surroundings to break the
numerous weak bonds that reinforce the native conformation). Thus, for denaturation, AS and
AH are both positive. Using the free-energy equation (AG = AH - TAS), explain why
denaturation becomes spontaneous at a certain temperature.