Which of the following gives Zwitter ion in its aqueous solution?

$A$ zwitter ion is

The naturally occurring amino acid that contains only one basic functional group in its chemical structure is

The bond that determines the secondary structure of a protein is

Globular protein is present in -

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