Protein | Molecular Weight (Da) | Isoelectric point (pI) | Does the Protein Contain a heme moiety? |
1 | 65,000 | 5.0 | No |
2 | 54,000 | 9.8 | No |
3 | 15,500 | 4.8 | Yes |
a.(1 point) What type of chromatography separates proteins based their charge?
b. (1 point) What type of chromatography separates proteins based on their size?
c.(6 points) Could gel filtration chromatography be used to separate a mixture containing Protein 1 and 3? Clearly explain why or why not. If gel filtration chromatography can be used to separate Protein 1 from Protein 3, which protein would elute first (clearly explain why)? After collecting the fractions from the column, the absorbance of each fraction will be measured using a spectrophotometer. Can both proteins (Protein 1 and Protein 3) be monitored at 280nm and 400nm (clearly explain)?
d. (5 points) Which 2 proteins listed in the table above could be separated by ion exchange chromatography but NOT by gel filtration chromatography (clearly explain why)?
e.(5 points) Which 2 proteins listed in the table above could be separated by gel filtration chromatography but NOT by ion exchange chromatography (clearly explain why)?
4. The ionization of p-nitrophenol is shown below (pKa = 7.0):
a.(4 points) Identify the weak acid and conjugate base.
b.(4 points)At pH 7, what are the relative concentrations of ionized and un-ionized p-nitrophenol?
c.(4 points)If enough concentrated hydrochloric acid is added to a solution of p-nitrophenol to lower the pH from 7 to 5, what will happen to the relative concentrations of the ionized and un-ionized forms?
d.(4 points) Ionized p-nitrophenol has a yellow color, while the un-ionized form is colorless. The yellow color can be measured using a spectrophotometer at 400nm. In order to determine the total amount of p-nitrophenol in a solution, would you perform the spectrophotometer reading at an acidic or basic pH? Clearly explain why?
SAMPLE | PROTEIN CONCENTRATION |
ABSORBANCE,610 nm |
Standard 1 | 1 mg/ml | 0.064 |
Standard 2 | 2.5 mg/ml | 0.154 |
Standard 3 | 5 mg/ml | 0.304 |
Standard 4 | 7.5 mg/ml | 0.449 |
Standard 5 | 10 mg/ml | 0.613 |
Unknown A | 0.870 | |
Unknown B | 0.375 |
6. (10 points) A protein was purified and then analyzed on a size exclusion column. Its MW was determined to be 90,000 Dalton. The SDS-PAGE gel shows two bands, corresponding to molecular weights of 10,000 and 35,000 Dalton. Describe the native conformation of this protein in terms of the number of subunits present and their molecular weight.
(12 points) You have a 250mM stock of glucose, a 25mM stock of asparagine, and a 0.050M stock of NaH2PO4, and magnesium chloride powder (solid form) , MgCl2 (Formula Weight; 95.21g/mole). How would you prepare (be specific) 150mL of a solution that contains 0.05M glucose, 5mM asparagine, 5mM NaH2PO4 and 150mM MgCl2?v
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.
Read moreEach paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.
Read moreThanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.
Read moreYour email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.
Read moreBy sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.
Read more