X-ray diffraction of wool shows repeated structural units spaced at 5.2 A, which is changed to 7.0 Å on steaming. This is due to the conversion of secondary structure from (a) B-sheet to random coil (b) a -helix to random coil (c) B-sheet to a -helix (d) a -helix to B-sheet
Option D
Wool with a 5.2A° repeat would be typical of an Alfa-keratin structure which is primarily alfa-helical. When this is steamed and stretched, the peptides are extended into ...