Question

A $\beta$-pleated sheet organisation in a polypeptide chain is an example of

• A. $1^o$ structure
• B. $2^o$ structure
• C. ${}^o$3 structure
• D. $4^o$ structure.

Answer 1

The correct option is B $2^o$ structure

Proteins are made up of amino acid that is bonded together by the peptide bonds. The primary structure of a protein is the covalent connection of proteins. It is a linear sequence of amino acid bound together with peptide bonds. Only in the secondary structure, there is a complex folding of the linear polypeptide chain into a specific structure which is the Alpha helical structure. When it is repeated, they form a pleated sheet-like structure. This forms the beta pleated sheet. This has hydrogen bonds in addition to the peptide bonds that provide stability to the protein and this is the secondary structure of the protein.

Thus, the correct answer is '2${}^0$ structure.'