1559T_ch26_454-46810/20/0515:39Pa9e465 EQA Solufions o Problems465 c.c ⊕ ead of a e)Amino acids:Ty-ly-ly-Phe-Met PossibleAUG-ACGAGGA-UUU-AUG-UGA.If the peptide utimatey synthesized would be His-Gly-Gly-Phe-Met. 51.2332 X 3 +3 (initiation codon)+3(termination codon)=7002. 52.(a)The more acidic SeH group will be deprotonated at pH7: C00 C00 -H compare HNH CH-SH At pH 7 you are above the p for the SeH group (5.2)but below the p for the SH in Cys(8.). 50. (a) (b) (c) Amino acids: Tyr-Gly-Gly-Phe-Met. Possible codons: AUG- U AC-GGA-GGA-UUU-AUG-UGA. If an A in the DNA strand were to mispair with C instead of U in the synthesis of this mRNA at the circled position, the result would be CAC instead of UAC, which codes for His instead of Tyr. So, the peptide ultimately synthesized would be His-Gly-Gly-Phe-Met. 51. 2332  3 3 (initiation codon) 3 (termination codon)  7002. 52. (a) The more acidic SeH group will be deprotonated at pH 7: At pH 7 you are above the pKa for the SeH group (5.2) but below the pKa for the SH in Cys (8.2). H3N H CH2Se COO H3N H CH2SH COO compare G C N N H N N OH OH NH O N NH O NH2 N H N H N NH NH N H N H N NH N N H N N HN This mispairing makes the A look like a G (it pairs with C instead of a U) Imine-A N H H H A N N H N NH NH N N H OH N T OH OH N N OH NH O O NH2 NH N H OH N N C NH N OH NH NH O Solutions to Problems • 465 1559T_ch26_454-468 10/20/05 15:39 Page 465