Chapter 18.7, Problem 18.23P

Interpretation Introduction

Interpretation:

$\text{α-helix}$ in fig $18.1$ is to be examined and number of backbone $C$ and $N$ atoms are included in the loop between an amide and carbonyl oxygen is 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.