The $\alpha$-helical model of protein was discovered by:

The peptide chains loop,twist and fold back on themselves due to the formation of . . . . . . bonds to form a stable tertiary structure of protein.

Which of the following amino acids is not aromatic?

What is the $R$ group present in glycine?

Which of the following groups are present in the structure of an amino acid?

In the structure of secondary proteins,the folding of the polypeptide chain is caused by which bond?