A mixture containing five amino acids (Ala, Asp, Gly, Phe, Pro) was analyzed using two methods of planar chromatography, paper and cellulose-coated thin layer. The solvent system was n-propanol/water (70/30 v/v). Predict the order of the mobility of the amino acids (low to high ) on the chromatograms.

Is chromatography a valid method for identifying amino acidsfrom an unknown mixture like serum? Wht or why not?

4. Assume that the unknown amino acid that you analyzed was not one of the 5 known amino acids on your chromatogram (Leu, Ala, Phe, Asp, Ser), but instead was one of the other 15 amino acids. Based on its Rf, what is the most likely identity of your unknown. Justify your conclusion.

5. If you boil an protein in hydrochloric acid it will break down to its constituent amino acids. Assume that you had done this to a typical protein and then had spotted these amino acids to a spot on the chromatograph. What pattern would you expect to see at the end of the experiment? Explain your prediction.

When considering anion exchange chromatography, which of the following statements best describes how increasing concentrations of NaCl elute the protein from the column?

Option A: The proteins that are bound to the chromatography resin are exchanged for Cl–.

Option B: The Na+ ions that are bound to the chromatography resin are exchanged for proteins.

Option C: The proteins that are bound to the chromatography resin are exchanged for Na+.

Option D: The Cl– ions that are bound to the chromatography resin are exchanged for proteins.

Given your answer to the question above, which of the following methods would be best suited for a one-step purification of lactate dehydrogenase from a hypothetical mixture of the three proteins?

Option A: anion exchange chromatography using a pH 9 buffer

Option B: anion exchange chromatography using a pH 5 buffer

Option C: anion exchange chromatography using a pH 10.5 buffer

Option D: anion exchange chromatography using a pH 7 buffer

Which of the following combinations of methods would be best suited for the purification of cytochrome c from a hypothetical mixture of the three proteins?

Option A: Gel filtration chromatography to obtain the low molecular weight proteins, followed by cation exchange chromatography at pH 8.

Option B: Cation exchange chromatography at pH 10, followed by elution at high [NaCl], and final purification using gel filtration chromatography.

Option C: Anion exchange chromatography at pH 10, followed by elution at high [NaCl], and final purification using gel filtration chromatography.

Option D: Cation exchange chromatography at pH 7, followed by elution at high [NaCl], and final purification using gel filtration chromatography.

How many amino acids are in the longest form of the human DNA methyltransferase?

Option A: 1511

Option B: 1882

Option C: 1606

Option D 1678