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Please show work A small generic section of the primary structure of an helix is

ID: 544905 • Letter: P

Question

Please show work A small generic section of the primary structure of an helix is given below. -amino acid-amino acid2-amino acida-amino acid4-amino acids- amino acids-amino acid (a) Which amino acid residue's backbone forms a hydrogen bond with the backbone of the third (3d residue? Choose the correct residue from the drop-down menu. amino acid [S-erans w-E (b) Which of the following peptide segments is most likely to be part of a stable helix at physiological pH? O -Glu-Glu-Glu-Glu-Glu- O -Gly-Gly-Gly-Ala-Gly- O-Gly-Arg-Lys-His-Gly- O -Tyr-Trp-Phe-Val-lle- O -Pro-Leu-Thr-Pro-Trp- O -Glu-Leu-Ala-Lys-Phe- O -Lys-Lys-Ala-Arg-Ser-

Explanation / Answer

a) a3 bind with a7 since on an average 3.6aminoacids are present per turn of an alpha helix

b) pI value of lysine=9.47&of serine =5.68.

pI value of the last peptide= 9.47+5.68/2=7.5 and this is the physiological pH