Practice question

Question

Q144 At 25°C values of [θ]222, the mean residue ellipticity at 222 nm, are - 33,000 and -3,000 deg cm2 dmol⁻¹ for a polypeptide existing in α- helical (α) and β-structure (β), respectively. If this polypeptide undergoes a two-state heat-induced α→β transition, and a value of [θ]222 = -18,000 deg cm2 dmol⁻¹ is observed at 60°C, then this observation leads to the conclusion that the α helix conversion to β- structure is: