Which one of the following is a globular protein?

Consider the following statements:
Statement-$I$: The primary structure of a protein represents its amino acid sequence.
Statement-$II$: The $\alpha$-helix and $\beta$-pleated sheet structures of a protein represent its tertiary structure.

Describe the term $D$ and $L$ configuration used for the amino acids with examples.

Name the molecule which is eliminated during the formation of a peptide bond.

The melting points and solubility in water of amino acids are generally higher than that of the corresponding halo acids. Explain.

Which of the following amino acids contains sulfur?