Which of the following proteins is present in silk?

The secondary structure of a protein refers to

What happens to the biological activity of a protein due to denaturation?

Pepsin enzyme hydrolyses:

$A$ codon has a sequence of $\underline{A}$,and specifies a particular $\underline{B}$ that is to be incorporated into a $\underline{C}$. What are $\underline{A}, \underline{B}, \underline{C}$?
$\underline{A} \quad \underline{B} \quad \underline{C}$

Which of the following is not an amino acid?