What happens to enzyme activity when the temperature increases beyond the optimal range?

Enzyme activity is highly dependent on temperature because enzymes, which are proteins, have a specific structure that is optimized for their function within a narrow temperature range. As the temperature rises and exceeds this optimal range, several changes occur within the enzyme's structure.

Firstly, increased temperature can lead to higher kinetic energy among molecules, resulting in more frequent collisions between enzymes and substrates, which might increase activity up to a point. However, when the temperature surpasses the optimal range, the bonds that maintain the enzyme's three-dimensional shape start to break down. This process, known as denaturation, alters the enzymes' active sites, preventing them from binding to substrates effectively. As a result, the overall catalytic activity of the enzyme decreases.

In some cases, extreme temperatures may cause irreversible denaturation, where the enzyme loses its functional shape permanently, resulting in drastically reduced or completely lost enzymatic activity. Hence, if the temperature continues to rise beyond what is optimal, the effective depletion of catalytic function occurs due to structural changes, leading to decreased enzyme activity and potential denaturation.