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## Problem Set 1 (due Fri Apr 18, 2014).51. The protein S100 was dissolved in aqueous solution to give

Problem Set 1 (due Fri Apr 18, 2014).51. The protein S100 was dissolved in aqueous solution to give a protein concentration of 1 mg/mL at 25 deg C.Human S100 amino acid sequence:MSELEKAMVALIDVFHQYSGREGDKHKLKKSELKELINNELSHFLEEIKEQEVVDKVMETLDNDGDGECDFQEFMAFVAMVTTACHEFFEHEGo to NCBI website (http:// and verify the S100 sequence.a. Based on the amino acid sequence, what is the calculated molar mass of the protein? (hint use theProtParam tool at What is the calculated extinction coefficient at 280 nm (280)?c. What is the molar protein concentration (in units of molar) of the S100 protein solution (1 mg/mL) andwhat is the expected absorbance at 280 nm (hint: A280 = 280[protein])?d. If the protein solution has osmotic pressure of 0.0011 atm (assume protein is uncharged), what is the molarmass of the protein dissolved in solution and how does it compare to the calculated mass in part âaâ?e. Give a molecular interpretation to explain why the molar mass determined in part âdâ might be differentfrom that in part âaâ.2. A bacterial cell has a cylindrical shape with 1 m diameter and 2 m long.a. Calculate the volume of the cell in nanoliters.b. If ribosomes occupy 20% of the bacterial cell volume, calculate how many ribosomes are present in a typicalbacterial cell (assume each ribosome has cylindrical shape with 14 nm diameter and 20 nm length).3. A 1-liter solution is prepared by mixing equal volumes of 1 M acetic acid and 1 M sodium acetate.a. What is the pH of the solution?b. What is the pH of the solution if 1 mL of 1 M HCl is added to the 1-liter solution?c. What is the pH of the solution if 10 mL of 10 M NaOH is added?4. In the reaction, ATP + glucose ADP + glucose-6-phosphate (Keq = 846at 25 C)a. What is G for the reaction?b. If [ATP] = [ADP] = [glucose] = [glucose-6-phosphate] = 1 mM at 25 C at the start of the reaction, what is Gfor the reaction under these conditions?c. If [ATP] = [ADP] = 1 mM at 25 C, what is the ratio of glucose-6-phosphate to glucose () thatwould allow the reverse reaction to begin?d. If [ATP] = [ADP] = 1 mM at 25 C, what isfor the reaction and which way would the spontaneous reactiongo if 1 mM glucose-6-phosphate was mixed with 1 M glucose (show all work)?5. A 40-residue peptide (all alanine) called poly-alanine adopts an alpha-helical structure under physiologicalconditions (25 C), but unfolds into a random coil structure at temperatures above 40 C.Poly-alanine: random coil helixa. What is H of helix formation if the helix is mainly stabilized by 10 main chain hydrogen bonds(hint: assume the bond dissociation energy for each H bond is 10 kJ/mol)?b. What is S of helix formation if the helix melting temperature is 40 C (ie 50% helix and 50%random coil exist at 40 C)?c. What is Keq for helix formation at 25 C (hint: assume H and S do not change withtemperature)?d. What is Keq for helix formation at 60 C?