20.
X-ray diffraction of wool shows repeated structural units spaced at 5.2 Å, which is changed to7.0 Å on steaming. This is due to the conversion of secondary structure from
A:
β-sheet to random coil
B:
α-helix to random coil
C:
β-sheet to α-helix
D:
α-helix to β-sheet
The answer is:
D
