1. Produce a figure with an appropriate figure legend of your SDS-PAGE gel that could be published in a scientific journal.
- Indicate all relevant information, e.g.origin, front, size of the molecular mass markers and casein and whey protein bands. You can use e.g. Power-Point, Photoshop or Illustrator or similar software for his task
- Write a concise figure legend with a minimal number of words that allows the reader to understand what he sees. Note: Give some information about the methods but do not repeat all details in the legend!
2. Fill in the table to report your calculated estimates for the molecular masses (kDa) of the proteins in the milk sample. You can enter up to 3 different significant bands that you observed in the respective fractions.
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Protein fraction
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Estimated molecular mass (kDa)
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Casein proteins
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Whey proteins
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Small molecular mass proteins
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3. Draw a graph of absorbance against fraction number for the gel filtration chromatography. Using Excel you will need to create a graph with two axes (one axis on the left for the absorbance of haemoglobin (Abs 400 nm) and one axis on the right for the absorbance of vitamin B12 (Abs 550 nm).
4. Explain in molecular terms the observed movement of the various sized proteins through:
a) the polyacrylamide gel
b) the gel filtration column
5. A cell consists of thousands of individual molecular components. To understand biochemical pathways is often necessary to separate, purify and analyse the molecular constituents of a cell. Name three different biochemical/biophysical properties in which biological molecules differ from each other and think about a corresponding technique that can be exploited to separate and/orcharacterize such metabolites.
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Biochemical/Biophysical property
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Technique that exploits this property
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Example given: different ionic charge
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Example given: separation on gel in electric field
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6. Consider an individual who had to dash for 500 metres in order to catch a tram that was just about to depart. Indicate thelikely concentration of metabolites that molecular analysis would reveal in the muscle tissue of this person. Increased, decreased and unchanged are describing levels relative to a healthy resting state.
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Metabolite
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Concentration
(Increased, decreased or unchanged)
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acetyl-CoA
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pyruvate
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lactate
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glucose (blood)
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glucose-6-phosphate
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EtOH
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glyceraldehyde-3-phosphate
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AMP
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glucose-1-phosphate
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ephinephrine
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