Enzymes play a crucial role in facilitating metabolic pathways within the cell. Describe how enzymes act as biological catalysts, and explain the significance of enzyme specificity in determining the course of biochemical reactions. How does enzyme-substrate binding influence reaction rates, and what factors can alter enzyme activity? Additionally, choose a specific metabolic pathway—such as glycolysis or the citric acid cycle—and discuss how enzyme regulation within this pathway is essential for maintaining homeostasis. In your response, consider how factors like allosteric regulation, feedback inhibition, or covalent modification can impact enzyme function and, consequently, overall cellular metabolism.