A small generic section of the primary structure of an α helix is given by − amino acid 1 − amino acid 2 − amino acid 3 − amino acid 4 − amino acid 5 − amino acid 6 − amino acid 7 − Which amino acid residue's backbone forms a hydrogen bond with the backbone of the second ( 2 nd ) residue? amino acid 3 Which peptide segment is most likely to be part of a stable α helix at physiological p H ?

a. − Glu − Leu − Ala − Lys − Phe −
b. − Gly − Arg − Lys − His − Gly −
c. − Tyr − Trp − Phe − Val − Ile −
d. − Lys − Lys − Ala − Arg − Ser −
e. − Gly − Gly − Gly − Ala − Gly −
f. − Glu − Glu − Glu − Glu − Glu −
g. − Pro − Leu − Thr − Pro − Trp −