The correct sequence of amino acids present in the tripeptide given below is

Which amino acid is not optically active?

The peptide that gives positive ceric ammonium nitrate and carbylamine tests is

$A$ protein undergoes reversible thermal denaturation from its initial state $N$ to denatured state $D$ according to $N \rightleftharpoons D$. At $60 ^\circ C$, the concentrations of both $N$ and $D$ are equal at equilibrium, and the standard enthalpy change of denaturation is $666 \text{ kJ mol}^{-1}$. The standard entropy change ($\Delta S^\circ$ in $\text{kJ K}^{-1} \text{mol}^{-1}$) of the protein upon denaturation at $60 ^\circ C$ is closest to

Which of the following is the correct structure of tyrosine?

Which of the following are protein fibers?