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Question: Explain the role of an enzyme in a biochemical reaction and its effect on the activation energy. Provide an example to support your explanation. Answer: An enzyme is a biological catalyst that speeds up biochemical reactions by lowering the activation energy required for the reaction to occur. Enzymes work by binding to substrate molecules and providing a highly specific active site where substrates can form a temporary enzyme-substrate complex. This complex brings the substrates closer together and properly orients them to react, thus reducing the activation energy. As a result, more reactants possess the necessary energy to participate in the reaction, leading to an increased reaction rate. For example, in a reaction where substrate A is converted to product P, the activation energy without an enzyme might be E1. However, with the enzyme present, the activation energy is reduced to E2 (where E2<E1), causing the reaction rate to increase.