The enzyme tyrosinase was successively extracted by combining a homogenate of a potato and sodium sulfate with ammonium sulfate. Tyrosinase was successfully extracted by taking advantage of solubility properties of certain proteins. A standard curve was generated indicating dopachrome absorbance values through the use of a spectrophotometer and a computer graphing program. A spectrophotometer was used to measure either the amount of light that passed through a solution (transmittance) of the amount of light absorbed by the solution (absorbance) at various wavelengths.
The preparation of the extraction included the use of a scale to weigh samples, the operation of a pipette, and finally setting up and reading the results of the spectrophotometer. While the results achieved were not perfectly text-book due to systematic error (human error, error in using the pipette, or sterility problems), a common trend could be found using linear regression to more accurately replicate perfect conditions. The graph indicated that a higher concentration of dopachrome yields a higher absorbance value on the spectrophotometer, which was expected as higher concentrations allow decreasing amounts of light to pass through. Essentially, the extraction of tyrosinase from potatoes was achieved and observed through coloration while tyrosinase was converting 8mM DOPA to 8mM dopachrome. The color observed was a deep orange, red. As solution concentration increases, the spectrophotometers produced higher readings of absorbance. These various concentrations of dopachrome yielded absorbance values that were in line with Beer's law. As stated in Beer's law, when electrons in an atom jump from higher energy levels to lowers one, they will give off excess energy in the form of light producing a line spectrum. The wavelengths or colors of this light will depend on the amount of energy being emitted by an atom. In conclusion, the color observed after the conversion of tyrosinase to DOPA and...
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