Florida Biology EOC Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

Enzymes play a crucial role in biological reactions primarily by lowering the activation energy required for those reactions to occur. Activation energy is the initial energy needed to start a chemical reaction; it acts as a barrier to the reactants. By providing an alternative pathway for the reaction, enzymes facilitate the transformation of substrates into products with less energy input.

As a result of this decrease in activation energy, reactions can proceed more efficiently and at a faster rate, which is essential for maintaining the metabolic processes necessary for life. Enzymes are highly specific to their substrates, meaning that each enzyme catalyzes only one type of reaction or a group of closely related reactions. This specificity, combined with the ability of enzymes to lower activation energy, enables precise regulation of metabolic pathways within cells.

While breaking down substrates is part of some enzyme functions, it does not encompass the full range of enzyme roles in biological reactions. Increasing temperature can affect reaction rates but is not a function of enzymes. Accelerating reactant rates is also a secondary effect of lowered activation energy rather than a direct role of the enzymes themselves. Thus, the main function of enzymes revolves around their ability to lower activation energy, making option B the most accurate answer.