An alpha-helix is a right-handed coil of amino-acid residues on a polypeptide chain. This coil is held together by hydrogen bonds between the oxygen of C=O on top coil and the hydrogen of N-H on the bottom coil. Such a hydrogen bond is formed exactly every 4 amino acid residues, and every complete turn of the helix is only 3.6 amino acid residues. This regular pattern gives the alpha-helix very definite features with regards to the thickness of the coil and the length of each complete turn along the helix axis.
The structural integrity of an alpha-helix is in part dependent on correct steric configuration. Amino acids whose R-groups are too large (tryptophan, tyrosine) or too small (glycine) destabilize alpha-helices. Proline also destabilizes alpha-helices because of its irregular geometry; its R-group bonds back to the nitrogen of the amide group, which causes steric hindrance.
Thus from above two peptide
i. LKAENDEAARAMSEA more likely to take up an alpha-helical structure,