The non-essential amino acid among the following is

Which of the following compounds will form a zwitterion?

Which of the following is an acidic amino acid?

What is the $pH$ of $0.01 \ M$ glycine solution? For glycine,$K_{a1} = 4.5 \times 10^{-3}$ and $K_{a2} = 1.7 \times 10^{-10}$ at $298 \ K$.

The most important energy carrier in all the living cells is

The total number of negative charges in the tetrapeptide,$Gly-Glu-Asp-Tyr$,at $pH$ $12.5$ will be $......$ .