The figure at right illustrates the definition of the ψ and φ backbone dihedral angles; the omega angle at the peptide bond is normally 180 °, since the partial-double-bond character keeps the peptide planar.
The figure at right illustrates the definition of the ψ and φ backbone dihedral angles. The omega angle at the peptide bond is normally 180 °. The partial-double-bond character keeps the peptide planar.