What role do enzymes play in chemical reactions within living organisms?

Enzymes are biological catalysts that significantly increase the rate of chemical reactions in living organisms without being consumed or permanently altered in the process. They achieve this by lowering the activation energy required for reactions to occur, allowing the reaction to proceed more quickly than it would in the absence of the enzyme. This catalytic function is essential for numerous biological processes, including digestion, metabolism, and cellular signaling.

Because enzymes are not consumed in reactions, they can repeatedly facilitate the same reaction multiple times, making them highly efficient. Their ability to accelerate reactions is crucial for maintaining the necessary speed of biochemical pathways that sustain life, especially since many of these reactions would occur too slowly to support cellular functions if it weren't for enzyme action. The effectiveness of enzymes is influenced by various factors, including temperature, pH, and the concentration of substrates, which are the reactants that enzymes act upon.