Question

Secondary structure of protein is mainly governed by:
A.Hydrogen bonds
B.Covalent bonds
C.Ionic bonds
D.Disulphide bonds

Answer 1

Hint: Proteins are long chains of amino acids bonded with peptide bonds. They are also known as polypeptides. To answer this question, you must recall the structures of proteins, namely primary, secondary, tertiary and quaternary structures.

Complete answer:
Proteins have various types of structures namely, primary, secondary, tertiary and quaternary structures and each of these structures refers to different levels of complexity in the chain. For example, in the primary structure of protein, we look only at the sequence of amino acids in the polypeptide chains. In the secondary structure, we observe the shape of the polypeptide chains.
Secondary structure of a protein refers to the shape of a protein exclusively due to hydrogen bonding between the carbonyl groups and the amide groups making the backbone of the chain. Secondary structure does not include the bonds formed between the carbon atoms of amino acids, hydrophobic interactions, or any other interactions that are associated with tertiary structure.
$\alpha -$ helix structure and $\beta -$ pleated sheet structure are the two most common secondary structures of polypeptide protein chains. Both these structures are the first significant steps in the folding of a polypeptide chain, and they establish many essential topological motifs that help to determine the subsequent tertiary structure and eventually the function of the protein.
The hydrogen bond in the molecules is formed between the carbonyl oxygen and the hydrogen attached to the nitrogen of the amine group.

Thus, the correct answer is A.

Note:
The tertiary structure of a protein tells us the nature of the folding in the secondary structure to determine between fibrous and globular structure. The quaternary structures represent the spatial arrangement of any subunits of the protein.