Which among the following amino acids is $NOT$ synthesized in our body?

The number of $sp^2$ hybridised carbons present in "Aspartame" is

Amino acids are produced on hydrolysis of:

$A$ tetrapeptide $x$ on complete hydrolysis produced glycine $(Gly)$,alanine $(Ala)$,valine $(Val)$,and leucine $(Leu)$ in equimolar proportions. The number of possible tetrapeptide sequences involving each of these amino acids exactly once is:

The number of disulphide linkages present in insulin are

What are the products of the enzymatic hydrolysis of proteins?