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Narrative
The enzyme glucose oxidase, is poured into two beakers containing buffer, horseradish peroxidase and a dye. Different concentrations of glucose are added to the two beakers. Glucose oxidase catalyzes the formation of gluconolactone from glucose. At the same time, the dye is converted to a colored compound. The formation of the blue-green color is used to follow the course of the reaction. The beaker with more glucose is a darker color, indicating that more gluconolactone was produced.

Discussion
Glucose oxidase catalyzes the formation of gluconolactone from glucose and also forms hydrogen peroxide as a by-product of the reaction. The horseradish peroxidase breaks down hydrogen peroxide into water and oxygen, using the dye as an electron donor. At the same time, the dye is converted to its oxidized form, which is a colored compound. Since the amount of hydrogen peroxide produced indicates how much reaction has taken place, the formation of the blue-green color can be used to follow the course of the reaction.