Which Is Not True About β-Sheets

Multiple Choice

Which is not true about β-sheets?

A) The side-chains of all amino acids point to the same side of the sheet.
B) The polypeptide chains in the sheet are nearly fully extended.
C) The range of allowed phi and psi angles is broader than for those in the α-helix.
D) In antiparallel sheets the hydrogen bonds between adjacent strands are nearly perpendicular to the backbones of the strands.