The total number of basic groups in the following form of lysine is:

$A$ sequence of how many nucleotides in messenger $RNA$ makes a codon for an amino acid?

In a protein molecule,various amino acids are linked together by:

For an amino acid,the ionization constant for the carboxyl group is $pK_{a_1} = 2.34$ and for the ammonium ion is $pK_{a_2} = 9.6$. At what $pH$ will the isoelectric point of the amino acid be?

Column-$I$	Column-$II$
$A$. Tyrosine	$P$. Essential amino acid
$B$. Serine	$Q$. Ceric Ammonium Nitrate
$C$. Tryptophan	$R$. Neutral $FeCl_{3}$
$D$. Proline	$S$. Carbylamine Test - Negative

Select the correct set of answer :

$\beta-$pleated sheets of polypeptide chains are present in