What is the role of enzymes in chemical reactions?

Enzymes play a crucial role in chemical reactions by functioning as catalysts. This means that they speed up the rate of a reaction without being consumed in the process. By lowering the activation energy required for a reaction to occur, enzymes enable reactions to happen more efficiently and at lower temperatures than would otherwise be possible.

Enzymes achieve this by providing an active site where substrates—the molecules upon which enzymes act—can bind. This interaction stabilizes the transition state, which helps the reaction proceed more easily. Since enzymes can facilitate a wide range of biochemical reactions in living organisms, they are fundamental to processes such as metabolism, DNA replication, and cellular signaling.

The other options represent concepts that do not accurately describe the function of enzymes. Enzymes do not increase activation energy; instead, they decrease it. They are not reactants themselves but rather molecules that assist in facilitating reactions. Additionally, they do not inhibit substrate attraction; rather, they enhance it by providing an environment conducive to reaction. Understanding the role of enzymes as catalysts underscores their importance in biological systems and their application in various scientific fields.