CHECK ALL ANSWERS THAT APPLY. THERE MAY BE MORE THAN ONE ANSWER FOR EACH QUESTIO
ID: 48978 • Letter: C
Question
CHECK ALL ANSWERS THAT APPLY. THERE MAY BE MORE THAN ONE ANSWER FOR EACH QUESTION. Thank you!
You know the molecular weight of the monomeric Enc protein; however you would like to get an idea of what the pI of the protein is. From the following options, what is the best way to estimate that?
[ ] SDS-PAGE
[ ] Size-exclusion chromatography
[ ] 2-D gel electrophoresis
[ ] "Salt out"
Protein analysis: You are attempting to separate a 60-subunit protein, Enc, from a mixture of other proteins. Each monomer has a molecular weight of 29 kDa. At pH 7.0, the protein has a net charge of -12. Which of the following options is the best way to purify this protein?
[ ] “Salt out” via ammonium sulfate precipitation and ion exchange chromatography
[ ] Ion exchange chromatography and size-exclusion chromatography
[ ] SDS-PAGE and affinity chromatography
[ ] “Salt out” via ammonium sulfate precipitation and affinity chromatography
I have two purified samples of the enzyme PKA (Protein Kinase A). One sample is treated with cAMP (cyclic AMP), while the other other is not. The cAMP-treated sample shows 2 bands on a non-denaturing PAGE, whereas the untreated sample shows only 1 band. What is the best explanation for this result?
[ ] PKA is activated by cAMP. The active enzyme would show more bands.
[ ] PAGE causes denaturation of the PKA.
[ ] cAMP unfolds PKA.
[ ] cAMP dissociates the regulatory and catalytic subunits of PKA.
You have some protein sample and you want to quantify it using a spectrophotometer. You take a small sample of protein and put it in a quartz cuvette, take a wavelength scan, and observe absorbance intensity at 280 nm. Which of the following is likely to make it so that you can analyze protein using a spectrophotometer?
[ ] Very concentrated protein sample
[ ] Proteins are composed of chiral molecules
[ ] The number of Trp and Tyr residues found in the amino acid sequence
[ ] All of the above
Explanation / Answer
[ ] 2-D gel electrophoresis
2-dimensional gel electrophoresis, shorten as two-D electrophoresis, is a form of gel electrophoresis which is used for analyzation of proteins.
[ ] “Salt out” via ammonium sulfate precipitation and ion exchange chromatography
purification of protein is a steps of processes to isolate few or a one proteins from a mixture, usually tissues,cells or whole organisms.
[ ] PKA is activated by cAMP. The active enzyme would show more bands.
[ ] PAGE causes denaturation of the PKA.
[ ] The number of Trp and Tyr residues found in the amino acid sequence