Which of the following is not an amino acid?

The general structure of $\alpha$-amino acid can be represented as shown below. Which amino acid is not correctly matched with the $R$ group given?

The molecular weight of protein is

Which of the statements about "Denaturation" given below are correct?
$A$. Denaturation of proteins causes loss of secondary and tertiary structures of the protein
$B$. Denaturation leads to the conversion of double strand of $DNA$ into single strand
$C$. Denaturation affects primary structure which gets distorted

Which is the $C$-terminal residue in glycyl alanine?

Optically inactive amino acid is :-