Chapter 18, Problem 18.70AP

Interpretation Introduction

Interpretation:

Bonding responsible for secondary structure of protein and atoms involved are to be identified.

Concept introduction:

Many amino acids are linked together through amide bonds to form a biologically large molecule known to be proteins.

Amino functional group is $(-N{H}_2)$ and carboxyl functional group is $(-COOH)$ and a $R$ group is considered as side chain, when all these are bonded to same carbon atom.

Secondary structure of protein is the repeating structural patterns ($\text{α-helix}$ and $\text{β-sheets}$) formed by hydrogen bonding between backbone atoms of the neighboring segments of protein.

$\text{α-helix}$ is the secondary protein structure in which a protein chain form a right handed coil stabilizes by hydrogen bonds between peptide groups along its backbone.

$\text{β-sheets}$ is the secondary structure in which adjacent protein in same or different molecules held together by hydrogen bonds alone the backbone giving rise to a flat sheet like structure.

Hydrogen bonding is an electrostatic attraction between hydrogen and an electronegative atom.