What typically happens to enzyme activity with a decrease in water activity?

Enzyme activity is heavily influenced by the availability of water in a given environment. A decrease in water activity typically leads to a reduction in enzyme activity. Enzymes require a certain level of hydration to maintain their three-dimensional structure, which is crucial for their function. When water activity decreases, it can result in enzyme denaturation or reduced flexibility, limiting the ability of enzymes to bind substrates and catalyze reactions effectively.

The interactions between enzymes and their substrates are largely facilitated by the aqueous environment, which aids in the movement of molecules. As water activity diminishes, the concentration of water molecules is lower, which can lead to slower biochemical reactions because the necessary collisions between enzymes and substrates become less frequent. Overall, the reduced water availability can hinder the functional properties of enzymes, resulting in decreased activity.