A C2 G This a photograph of an actual polyacrylamide gel that has been run with samples of protein. For each question, write the letter from the item in the gel that best matches the word or concept that is described. Answers may be used once, more than once, or not at all. There may be more than one correct answer per question. 1. Band 2. Lane 3. Well 4. Will protein migrate through the gel from A to B or will it migrate from B to A? 5. Which end is nearest the negative electrode, A or B? 6. Which contains smaller protein fragments, F or G? 7. Which letter indicates the highest concentration of protein fragments that are the same size 8. Where would a sample of protein be loaded? B.

When a protein is denatured using heat Select one: a. its C-terminal will change. b. its tertiary structure will change. c. its amino acid sequence will change. d. its amino acid composition will change.

How could you make the zwitterion of aspartic acid more soluble in water?

6. A protein has a molecular mass of 400 kDa when measured by size-exclusion chromatography. When subjected to gel electrophoresis in the presence of SDS the protein gives three bands with molecular m of 180, 160, and 60 kDa. When electrophoresis is carried out in the presence of SDS and dithiothreitol (DTT), three bands again form, this time with molecular masses of 160, 90, and 60 kDa. a. Approximately how many amino acids are present in a 400 kDa protein. (show work) b. How many grams would there be in a nanomole of this protein? (show work) C. What is the purpose of adding DTT? d. How many subunits does the protein have, and what are their molecular weights?