What is a common outcome when an enzyme's active site is altered?

When an enzyme's active site is altered, it typically leads to a decreased enzyme activity. The active site of an enzyme is specifically shaped to bind to its substrate, and any change to this structure can prevent the substrate from fitting properly, thus inhibiting the enzyme's ability to catalyze the reaction.

This alteration can occur due to various factors, such as mutations, changes in environmental conditions (like pH and temperature), or the presence of inhibitors. When the enzyme can no longer interact effectively with its substrate, the overall rate of the reaction it catalyzes will decrease, resulting in lowered enzyme activity.

Understanding this concept underscores the importance of the enzyme's three-dimensional shape in its function, as even slight changes can have significant effects on its role in biological processes.