Which is an essential constituent of diet?

Assertion : Carboxypeptidase is an exopeptidase.
Reason : It cleaves the $N$-terminal bond.

Which of the following is a Zwitter ion?

The general structural formula of $\alpha$-amino acid is $NH_2-CH(R)-COOH$. The group $R$ in tryptophan $(X)$ and histidine $(Y)$ are respectively:

Match List-$I$ with List-$II$.

List-$I$ (Natural amino acid)	List-$II$ (Code)
$A$. Glutamic acid	$I$. $Q$
$B$. Glutamine	$II$. $W$
$C$. Tyrosine	$III$. $E$
$D$. Tryptophan	$IV$. $Y$

What is the molecular weight of a protein?