The dipeptide given below is used as:

Glycylalanine is a dipeptide of which amino acids?

Name two $\alpha$-amino acids which form a dipeptide which is $100$ times more sweet than cane sugar?

Assertion $(A)$: An optically active amino acid can exist in three forms depending on the $pH$ of the solution.
Reason $(R)$: Amino acids contain both acidic and basic groups; they exist as a zwitterion in aqueous medium,anionic form in basic medium,and cationic form in acidic medium.

Which of the following is not a function of proteins?

The trace metal present in insulin is