Asmall generic section of the primary structure of an α helix is given by −amino acid1−amino acid2−amino acid3−amino acid4−amino acid5−amino acid6−amino acid7− which amino acid residue's backbone forms a hydrogen bond with the backbone of the first (1st) residue? which peptide segment is most likely to be part of a stable α helix at physiological ph ? −pro−leu−thr−pro−trp− −tyr−trp−phe−val−ile− −gly−gly−gly−ala−gly− −glu−leu−ala−lys−phe− −gly−arg−lys−his−gly− −lys−lys−ala−arg−ser− −glu−glu−glu−glu−glu−