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Unformatted text preview: NAME (print, no nicknames): Key (Differences between A and B versions noted, also in some cases the B version questions were in a different order.) Page 1 of 5 WRITE YOUR NAME LEGIBLY ON EVERY PAGE CHECK TO BE SURE YOU HAVE 5 PAGES INCLUDING COVER PAGE. I swear/affirm that I have neither given nor received any assistance with this exam. Signature: Date: BIOCHEMISTRY 460 EXAM 2A March 29, 2010 Read each question carefully Budget your time wisely Please put your name on every page. BE SURE TO STATE UNITS OF ANY NUMERICAL ANSWERS. USEFUL CONSTANTS : R (gas constant) = 8.315 J mol 1 Kelvin 1 = 8.315 x 10 3 kJ mol 1 Kelvin 1 If temperature = 25 C, absolute temperature T = 298 K (Assume this temperature unless problem states otherwise.) F (Faradays constatnt) 96,500 J V 1 mol 1 = 96.5 kJ V 1 mol 1 NAME (print, no nicknames): Key (Differences between A and B versions noted, also in some cases the B version questions were in a different order.) Page 2 of 5 1. Use the table below to answer question 1 Protein Molecular Weight (kD) pI Biological Function Mitochondrial Hsp60 60.0 5.2 Chaperone Superoxide dismutase III 100 6.1 Catalyzes the neutralization of superoxides in the blood antitrypsin 45.0 5.4 Trypsin inhibitor Histone H1d 21.2 10.9 Binds DNA in eukaryotic cells Src kinase 60.0 4.8 Protein kinase involved in cell signaling A. (4 points) You apply a mixture of the proteins above to an anion exchange column. Which two proteins would you have difficulty separating with this technique? Why? Mitochondrial Hsp60 and -antitrypsin because the pIs are close so difficult to separate based on charge B. (3 points) You purify superoxide dismutase to homogeneity. Determination of its mass by gel filtration chromatography yields 100 kD. You repeat the gel filtration chromatography in the presence of 6 M urea and 10 mM -Mercaptoethanol and now find a single species of 25 kD elutes from the column. Based on these experiment, what is the quaternary structure of superoxide dismutase. Explain your answer for full credit. Homotetramer -mercaptoethanol breaks disulfide bonds) holding together quaternary structure Version B: Homodimer same reasoning C. (3 points) Suppose you wanted to purify mitochondrial Hsp60 from liver mitochondria. What step would you take after cell homogenization to assure you have a fraction rich in that protein? Cell fractionation to separate mitochondria 2. Consider the glycolipid: A. (5 points) Carefully label the polar head group, circle the backbone, and label the fatty acyl tail. Is the fatty acyl tail saturated or unsaturated? Why? Saturated, no double bonds B. (5 points) Would you expect to find this lipid on the extracellular face of the membrane, the intracellular face of the membrane, or both? Please explain your answer. Extracellular glycolipids found on extracellular and do not undergo transverse (flip flop) diffusion p. 2 (20 points) p. 3 (20 points) p. 4 (30 points)...
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This note was uploaded on 05/06/2010 for the course BIOC 460 taught by Professor Ziegler during the Spring '07 term at University of Arizona- Tucson.
- Spring '07