The proteins with a prosthetic group are called

Among the following,the achiral amino acid is

$A$ short peptide on complete hydrolysis produces $3$ moles of glycine $(G)$,$2$ moles of leucine $(L)$ and $2$ moles of valine $(V)$ per mole of peptide. The number of peptide linkages in it are $..............$.

$\beta-$pleated sheets of polypeptide chains are present in

Which structure of protein remains intact after coagulation of egg white on boiling?

Optically inactive amino acid is :-