Question

At some points a protein molecule may be folded back on itself. This is called _____structure and folds or coils are held together in place by ______

• A. $2^{\circ },$ H-bonds
• B. $2^{\circ },$ peptide bonds
• C. $3^{\circ },$ H-bonds
• D. $1^{\circ },$ peptide bonds

Answer 1

The correct option is A $2^{\circ },$ H-bonds

The primary structure of proteins is the covalent connections. It refers to the linear sequences, number and nature of amino acid. They are bonded by peptide bonds only. When there is folding in the linear polypeptide chain into the specific coiled structure, it is known as a secondary structure.
In the secondary structure, the hydrogen bonds are also formed. It stabilises the complex structure of the secondary structure of the protein. These are found in the keratin of hairs, feathers, and silk fibres.

So, the correct answer is option (a).