Chapter 22.14, Problem 44P

Interpretation Introduction

Interpretation:

The length of an α-helix that contains 74 amino acids has to be determined. The length of fully extended peptide chain that contains 74 amino acids has to be determined.

Concept introduction:

$\alpha -Helix$ is a type of secondary structure where segments of repetitive conformations forms the backbone chain of a peptide or protein. The backbone of polypeptide in an $\alpha -helix$ is coiled around the axis of protein molecules.

α-helix has 3.6 amino acids in its each turn.

The length of a turn of α-helix is $5.4A^{\circ }$.

The distance between consecutive amino acids in a fully extended peptide chain is $3.5A^{\circ }$.