Question

Choose the correct statements about proteins:

• A. Primary structure of protein refers to the amino acid sequence
• B. Interaction between three polypeptide chains gives rise to the tertiary structure of proteins
• C. Association between four polypeptide chains gives the quaternary structure of proteins
• D. Folding of polypeptide chains due to an interaction between the carbonyl group and the amine group of a peptide linkage gives rise to the secondary structure

Answer 1

Answer: (A), (D)

The correct options are
A Primary structure of protein refers to the amino acid sequence
D Folding of polypeptide chains due to an interaction between the carbonyl group and the amine group of a peptide linkage gives rise to the secondary structure

a) The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain.

b) The tertiary structure of protein refers to the three dimensional shape of a protein. It consists of various interactions including hydrogen bonds, hydrophobic and dipole-dipole interactions, disulphide linkages.

c) Some proteins are made up of multiple polypeptide chains and these subunits come together, they give the protein its quaternary structure.

d) Secondary structure is defined by the pattern of the hydrogen bond between the amino hydrogen and carboxyl oxygen atoms in the peptide backbone. The most common types of secondary structures are the α helix and the β pleated sheet.