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Proteins

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Question 1

Collagen is a fibrous structural protein widely used in cosmetic formulations. To verify the quality of marine-derived collagen extracts, a biochemistry laboratory determines the protein concentration of their samples using a colorimetric assay.

To produce a calibration curve for this assay, you are provided with:

  • A stock collagen solution of known concentration (2.0 mg/cm32.0\text{ mg/cm}^32.0 mg/cm3)
  • Distilled water
  • Biuret reagent (which reacts with the peptide bonds of proteins to form a purple complex)
  • A colorimeter

Calibration curve for collagen concentration

1.

Use the information provided to describe how you could produce a calibration curve for collagen concentration. Do not include details on the use of specific glassware (such as pipettes or test tubes) in your answer.

[4]
2.

Describe how you would determine the concentration of collagen in an unrefined marine extract sample using your calibration curve.

[2]

Proteins Questions

  1. A Level
  2. /Biology
  3. /Proteins

Question bank