why-do-the-first-and-last-four-amino-acid-residues-in-an-alpha-helix-not-fully-p

Question

Why do the first and last four amino acid residues in an alpha helix not fully participate in hydrogen bonding?

Accepted Answer

They are not positioned to form hydrogen bonds with other residues.

Answer

They lack the necessary functional groups for hydrogen bonding.

Answer

They are too flexible to maintain stable hydrogen bonds.

Answer

They are involved in forming disulfide bonds instead.