BCHM 461_0101 Name______________________________________ 1October 16 2012Dr. Paul PaukstelisExam 1Exams written in pencil or erasable ink will NOT be re-graded under any circumstances.The University of Maryland Honor PledgeThe Honor Pledge is a statement that University of Maryland students are required to write out and sign on examinations.The Pledge reads:I pledge on my honor that I have not given or received any unauthorized assistance on this examination.After you have completed this examination, please hand-write this pledge into the box below, followed by your signature. Score:#1_______/30#2_______/60#3_______/60#4_______/50Total: /200BCHM 461_0101 Name______________________________________ 2October 16 2012Dr. Paul PaukstelisExam 1(200 points)1) (30 points ) BioenergeticsA process is observed to be spontaneous with the value of ΔH for this process greater than 0.A. (10 points) What general conclusions can you draw about the values of ΔS, ΔG, and ΔH. What drives this process?B. (8 points) Describe a likely scenario if the temperature under which this process is observed is decreased. Be specific.C. (6 points) Write down the formula you used to come to conclusions in the above questions.D. (6 points) Describe two ways we can drive a simple reaction, A B + C, in the forward direction.BCHM 461_0101 Name______________________________________ 3October 16 2012Dr. Paul Paukstelis3)(60 points) Nucleic AcidsA) (20 points) Beginning with the partial image below, draw a second RNA nucleotide through a standard 5'->3' phosphodiester linkage. As part of your drawing, In the box provided draw an adenine nucleobase connected through a standard glyosidic linkage.B)(12 points) On the image above, draw the mechanism for alkaline hydrolysis of RNA. Use arrows for electrons pushing. Identify the nucleophile, what is activating the nucleophile, and the intermediate.D) (12 points)BCHM 461_0101 Name______________________________________ 4October 16 2012Dr. Paul PaukstelisE) (4)(60 points) Peptide Chemistry and Chemical StructureYou are working with a peptide of 14 residues:G R T L L K N T A Y A K W RA)(30 points) You digest this peptide using the endopeptidase trypsin. How many peptides will you have after complete digestion? Draw the complete chemical structure of the peptide with the most residues following the digestion. B)(6 points) On the chemical structure you drew above, clearly identify the ionizable functional groups present in the peptide.C)(12 points) You now completely digest the starting peptide with chymotrypsin, trypsin, and cyanogen bromide together. Using one letter abbreviations, write down all of the peptides resulting from this digestion.BCHM 461_0101 Name______________________________________ 5October 16 2012Dr. Paul PaukstelisD)(12 points) Based on the digest performed in Part C, identify the least basic peptide. Briefly explain why you chose this peptide and estimate its pI.5) (50 points) Think it through. You are given six solutions (A, B, C, D, E and F). Each of the solutions contains the following molecules:Mol1) 5'-ATGGATCCAGA-3' and 5'-TCTGGATCCAT-3'Mol2) 5'-ATGGGCTCAGGA-3' and 5'-TCCTGAGCCCAT-3'Mol3) 5'-ATGGATCCAGA-3' and 5'-TCTGGATCCAT-3' and 6M Urea (a chaotropic agent)Mol4) Asp-Glu-Lys-Lys-Thr-Cys-Ile-Leu-LeuMol5) Asp-Glu-Lys-Lys-Thr-Cys-Ile-Leu-Leu and DTT (a reducing agent)Mol6) W-H-Y-F-I-N-G-F-I-R-E-A-L-A-R-MYou acquire (or are given) the following experimental data for the six solutions:Solution A: absorbance maximum at 260 nm with A260 = 1.0Solution B: absorbance maximum at 280 nm with ε280(M-1 cm-1) = 6970Solution C: absorbance maximum at 260 nm, A260 = 0.5, Tm = 38ºCSolution D: no absorbance in the 250-290 nm rangeSolution E: absorbance maximum at 280 nm with ε280(M-1 cm-1) = 120Solution F: absorbance maximum at 260 nm and Tm = 30ºCBelow, assign each molecule to a solution. Each molecule can only be assigned once. In the space provided you must briefly justify your answer by identifying how chemical moieties and/or physical properties of the molecule you assign fit the data. A) (10 points) Mol1 is assigned to B) (10 points) Mol2is assigned to C) (10 points) Mol3 is assigned to D) (8 points) Mol4 is assigned toBCHM 461_0101 Name______________________________________ 6October 16 2012Dr. Paul PaukstelisE) (6 points) Mol5 is assigned to F) (6 points) Mol6 is assigned toBCHM 461_0101 Name______________________________________ 7October 16 2012Dr. Paul PaukstelisTHIS IS A SCRATCH PAGE FOR CALCULATIONS. DO NOT INCLUDE OR REFERENCE ANSWERS TO THIS PAGE. THE VERY FIRST THING I AM GOING TO DO IS TEAR THIS PAGE OFF AND THROW IT IN A RECYLING BIN