Which statement below is most correct regarding the alpha helical structure of polypeptide chains in proteins?
A) It is primarily dependent upon hydrogen bonding.
B) It is primarily dependent upon disulfide linkages.
C) It is found in all proteins.
D) It refers to interactions between adjacent chains in fibrous proteins.

Question

Quizplus · Accepted Answer

The alpha helical structure of polypeptide chains is primarily dependent upon hydrogen bonding between the carbonyl group of one amino acid and the amino group of an amino acid four residues down the chain. Disulfide linkages are more involved in stabilizing tertiary and quaternary protein structure, and not specifically the alpha helix. Not all proteins contain alpha helices, and this structure is not specific to fibrous proteins.

Which Statement Below Is Most Correct Regarding the Alpha Helical