structure and function q

[Bestie]

α-Keratin is a fibrous protein that can be
stretched to about twice its length and is elastic.
Silk fibroin is also a fibrous protein but is not
elastic. Silk has great tensile strength and is much
stronger than hair. Explain these observations in
terms of the structure of their protein molecules.

is the answer related ti teriary structure and how silk may have stronger bonds there?

[vceva]

I think the answer is related to the secondary structure.
Keratin is generally made out of alpha helix (intramolecular hydrogen bonds)which allow it to have stretch-ability
On the other hand, beta-pleated sheets in silk have inter-molecular hydrogen bonds which provide greater structure and strength.