- What one of the following is not true for an alfa helix?
a) It is one of the most important secondary structure.
b) It has a net dipole moment
c) All hydrogen bonds are aligned in the same direction.
d) Long stretches of left handed alpha-helices occur in proteins.
Explanation:
Proteins contain only L-amino acids, for which a right-handed alpha helix is by far the more stable and only right handed alpha helices are present in proteins.
Answer: Long stretches of left handed alpha-helices occur in proteins.
Ref: Harper 30th Ed. Page-