Amanda’s Blog

  Alcohol dehydrogenase catalyzes the reaction of ethanol and NAD⁺ to form acetaldehyde and NADH. Since NADH is a product, absorbance values go up as the reaction progressed; therefore higher absorbance values mean an increase in activity. Lactose dehydrogenase catalyzes the reaction of pyruvate, NADH and H⁺ to lactate and NAD⁺. NADH is a reactant in this case; therefore lower absorbance values indicate an increase in activity. A progress curve plots absorbance values of NADH over the course of the reaction. The progress curve in an ADH experiment will show an upward trend while the progress curve in an LDH experiment will show a downward trend.