Human enzymes have an optimal temperature of approximately 37°C, while thermophilic bacterial enzymes have an optimal temperature of approximately 75°C. Which of the
following statements best explains the change in the rate of these enzymatic reactions
between 40°C and 70°C?

The rate of reaction of the human enzyme decreases as the reaction requires less energy to
þroceed, while the rate of the reaction of the thermophilic bacterial enzyme increases as
the reaction requires more energy to proceed.

The rate of reaction of the human enzyme decreases as the enzyme denatures, while the
rate of the reaction of the thermophilic bacterial enzyme increases as molecules move
faster, causing more collisions between the enzyme and substrate.

The rate of reaction of the human enzyme decreases as the entire enzyme denatures, while
the rate of the reaction of the thermophilic bacterial enzyme increases as only the active
site of the enzyme denatures at higher temperatures, allowing for a tighter fit with the
substrate.

The rate of reaction of the human enzyme decreases as the molecules move slower and
fewer collisions occur between the enzyme and the substrate, while the rate of the
reaction of the thermophilic bacterial enzyme increases as molecules move faster,
causing more collisions between the enzyme and substrate.