Final answer:
The products of the first enzyme-catalyzed reaction in metabolic pathways typically become substrates for subsequent enzymatic reactions, with pathways being either energy-requiring or energy-releasing.
Step-by-step explanation:
In a multistep metabolic pathway, the products of the first enzyme-catalyzed reaction typically become the substrates for subsequent reactions. These metabolic pathways can be anabolic, requiring energy to synthesize more complex molecules, or catabolic, releasing energy by breaking down complex molecules into simpler ones. The enzymes involved in these pathways are crucial as they catalyze each step, facilitating the reactions that would not otherwise occur spontaneously.
For instance, during glycolysis, the first enzyme, hexokinase, converts glucose into glucose-6-phosphate which then continues through the pathway leading to the production of energy in the form of ATP. The initial products in a metabolic pathway are often specifically tailored by the enzymes to fit the next step in the pathway, and can be subject to feedback regulation to maintain metabolic balance within the cell.