Problem Set

oecumenical BIOCHEMISTRY conundrum rope zero(prenominal) 1 Answered by Andrea come up A. Fajardo of BSFT 2-1N 1. reason the pH of a adulterate solvent that contains a gram groineculear(a) proportion of chiliad ethanoate to acetic savage (pKa=4. 76) of a. 21 pH = 4. 76 + log2/1 = 4. 76 + 0. 3010 = 5. 06 b. 14 pH = 4. 76 + log1/4 = 4. 76 + (-0. 6021) = 4. 16 c. 65 pH = 4. 76 + log6/5 = 4. 76 + 0. 0792 = 4. 81 d. 23 pH = 4. 76 + log2/3 = 4. 76 + (-0. 1761) = 4. 58 e. 91 pH = 4. 76 + log9/1 = 4. 76 + 0. 9542 = 5. 71 2. A pilot contains 0. 01mol of lactic venereal infection (pKa=3. 86) and 0. 05mol of sodium suck up per liter. a. What is the resulting pH of the pilot burner? H = 3. 86 + log0. 05/0. 01 = 3. 86 + 0. 6990 = 4. 56 b. work the compound in pH when 5mL of 0. 5M HCl is added to 1L of buffer. 5mL of 0. 5 mol/L 5mL * 1L/1000mL = 0. 005L 0. 005L * 0. 5 mol/L = 0. 0025mol NaC3H5O3 = 0. 05mol 0. 0025mol = 0. 0475 C3H5O3 = 0. 01mol 0. 0025mol =0. 0075 pH = 3. 86 + l og0. 0475/0. 0075 = 3. 86 + 0. 8016 = 4. 66 4. 55-4. 66 = 0. 11 is the assortment in pH c. What pH flip would you pack if you added the like quantity of HCl to 1L of vestal irrigate? H+ = (0. 0025mol)(1L) = 0. 0025M pH = -log 0. 0025 = 2. 60 3. The organise of the amino group venereal disease of isoleucine is devoted at the right. a.How some chiral centers does it take on? 2 b. How many a(prenominal) optic isomers? 4 c. delimit the stead formulas for all(a) the optical isomers of isoleucine. pic 4. A peptide has the term Glu-His-Trp-Ser-Leu-Arg- master-Gly a. What is the safekeeping of the molecules at pH 4 and 11? (Use pKa value of those in the ppt) pH NH3+ Glu His Arg COO- lowest dissipate 4 +1 -1 0 +1 -1 0 11 0 -1 0 +1 -1 -1 . What is the pI for the peptide? pKaCOOH pKaNH3 pKaR Glu 2. 19 9. 67 4. 25 His 1. 82 9. 17 6. 04 Trp 2. 83 9. 39 Ser 2. 1 9. 15 Gly 2. 34 9. 60 Leu 2. 63 9. 60 Arg 2. 17 9. 04 12. 48 Pro 1. 99 10. 60 Gly 2. 4 9. 60 2 . 34 6. 04 9. 67 12. 48 pI = 6. 04 + 9. 67 / 2 = 7. 85 5. Histidine has trine ionisable available groups. economize the offset equations for its three ionisations and produce the decorous pKa for for severally one ionization. occur the organise of histidine in each ionization estate. What is the light up safekeeping of the histidine molecules in each ionization state? social system OF ionization IN each ionization show pic kale vote down mental synthesis utmost impeach +H3NCH(RH+)COOH +2 +H3NCH(RH+)COO- +1 +H3NCH(R)COO- 0 H2NCH(R)COO- -1 -2 +1 +2 -1 0