What role do catalysts play in biological reactions?

Catalysts are substances that increase the rate of a chemical reaction without being consumed in the process. In biological systems, enzymes serve as catalysts that facilitate biochemical reactions by lowering the activation energy required for those reactions to proceed. This means that in the presence of a catalyst, reactants can convert into products more efficiently and at a faster rate, allowing metabolic processes to occur under the mild conditions typically found in living organisms.

By reducing the energy barrier for the reaction, enzymes enable the reactions to happen at temperatures that are compatible with life, thereby supporting the complex biochemistry of cells. This feature is essential in maintaining the necessary speed for reactions that support various physiological functions.

The other options do not accurately describe the role of catalysts. They do not inherently increase temperature, nor do they get consumed in the reaction or alter pH levels; instead, they specifically function to enhance reaction rates by lowering activation energy.