Amino acids are produced on hydrolysis of:

Which one of the following is an amino acid?

Which of the following is an essential amino acid?

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ solution of the product obtained by heating a mole of glycine with a mole of chlorine in the presence of red phosphorus generates a chiral carbon atom.
Reason $R$: $A$ molecule with $2$ chiral carbons is always optically active.
In the light of the above statements,choose the correct answer from the options given below:

Which compound can exist in a dipolar (zwitter ion) state?

The value of $x$ in compound '$D$' is $.........$.