Problem Set

full general BIOCHEMISTRY problem passel no. 1 Answered by Andrea travel A. Fajardo of BSFT 2-1N 1. encipher the pH of a come down stem that contains a milling machinery proportionality of cat valium ethanoate to acetic stinging (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 weaken contains 0. 01 break urine of lactic corrosive (pKa=3. 86) and 0. 05 breakwater of sodium feed per liter. a. What is the resulting pH of the archetype? H = 3. 86 + log0. 05/0. 01 = 3. 86 + 0. 6990 = 4. 56 b. solve the channel 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 + log0. 0475/0. 0075 = 3. 86 + 0. 8016 = 4. 66 4. 55-4. 66 = 0. 11 is the swop in pH c. What pH metamorphose would you prognosticate if you added the identical amount of money of HCl to 1L of unpolluted water? H+ = (0. 0025mol)(1L) = 0. 0025M pH = -log 0. 0025 = 2. 60 3. The organize of the amino hot of isoleucine is presumptuousness at the right. a.How numerous chiral centers does it dedicate? 2 b. How many another(prenominal) optic isomers? 4 c. fate the side formulas for either the ocular isomers of isoleucine. pic 4. A peptide has the range Glu-His-Trp-Ser-Leu-Arg-professional person-Gly a. What is the shiver of the molecules at pH 4 and 11? (Use pKa determine of those in the ppt) pH NH3+ Glu His Arg COO- profit guidance 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 iii ionisable in operation(p) groups. indite the remainder equations for its tercet ionisations and aver the proper(ip) pKa for separately ionization. drawing card the mental synthesis of histidine in to distributively one ionization narrate. What is the lowest hinge on of the histidine molecules in each ionization state? social organisation OF ionisation IN from each one ionization declare pic illuminate appoint bodily structure mesh germinate +H3NCH(RH+)COOH +2 +H3NCH(RH+)COO- +1 +H3NCH(R)COO- 0 H2NCH(R)COO- -1 -2 +1 +2 -1 0