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Β-Galactosidase Lab Report

Satisfactory Essays

With both the stock substrate and varying enzyme solutions prepared, the Spec20 spectrophotometer was used to investigate the enzymatic activity of β-Galactosidase through an absorbance-based assay. Using LoggerPro software on the computer to analyze the absorption data, the Spec20 was calibrated before each run with 0.5 mL of the tested enzyme concentration at an absorbance of 420 nm. Data collection was then started, instantly followed by the addition of 0.5 mL of the stock 2.5 mM substrate solution, topping off the 1-mL cuvettes. Each of the nine varying enzyme concentrations were split between the team and run for a total of 10 minutes. Upon completion, data from each varying enzyme concentration was copied to a single Excel sheet and used …show more content…

From the stock substrate solution of 2.5 mM, each group serially diluted at least one different substrate concentration for a total of four different substrate concentrations to be investigated: 1.25 mM, 1.0 mM, 0.75 mM, 0.25 mM. The enzyme concentration was kept constant at 2.0 mM while experimenting on the affect of varying enzyme concentration on the rate and product formation of ONP. Enough 2.0 mM enzyme solution was prepared in the previous part of the project to supply this assay. Using similar procedure to collect absorbance data as the first part, 0.5 mL of 2.0 mM enzyme concentration was placed into the cuvette and used to calibrate the spectrometer at 420 nm. Data was then started, with the immediate addition of 0.5 mL of varying substrate concentrations. Each varying substrate concentration was split between the team and run for a total of 10 minutes, with the exception of the 1.25 mM run. Upon completion, data from each varying substrate concentration was copied to a single Excel sheet and used to produce an absorbance vs. time graph, product formation vs. time graph, Michaelis Menten plot, and Lineweaver-Birk plot. This analysis was used to calculate the V0,Vmax, and Km for β-Galactosidase

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