An example of a sulphur-containing amino acid is:

$1.78 \ g$ of an optically active $L$-amino acid $(A)$ is treated with $NaNO_{2} / HCl$ at $0^{\circ}C$. $448 \ cm^{3}$ of nitrogen at $STP$ is evolved. $A$ sample of protein has $0.25 \%$ of this amino acid by mass. The molar mass of the protein is

$A$ peptide synthesized by the reactions of one molecule each of Glycine,Leucine,Aspartic acid and Histidine will have ..... peptide linkages.

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

The total number of isomeric linear dipeptides which can be synthesised from racemic alanine is

The secondary structure of protein refers to .......