Molecule acting as substrate or product in a biochemical pat

Solution

When you observe any biochemical pathway, the substrate for a perticular reaction is the product of their upstream reaction. For example, if you observe the glycolysis pathway, glucose converted into glucose-6-phosphate. Here, glucose is substrate and glucose-6-phosphate is product. In the subsequent reaction, glucose-6-phosphate converts into fructose-6-phosphate. Here glucose-6-phosphate is substrate and fructose-6-phosphate is product.