Chapter 21, Problem 18A

Interpretation Introduction

Interpretation:

The structure of collagen protein must be described. The function of this protein in human body must also be explained.

Concept Introduction:

Collagen is a protein which is a main constituent of bone, ligaments, tendons and skin.

Answer to Problem 18A

A collagen molecule can make fibrils containing three peptide strands which are left handed helix.

Collagen is present in the main connective tissues and thus it gives strength and support to the human body.

Explanation of Solution

The three left handed helix of fibrils are involved in quaternary structure formation by twisting together into a triple helix (which is right handed). This quaternary structure is stabilized by many hydrogen bonds formation. Each of the three collagen subunits has three chains which are made up of amino acids with regular arrangement.

Collagen is used to form the connective tissues like bone, tendons, ligaments and skin. Bone gives strength and support the body. Ligaments are used to join bones. Tendons are used to join bone with muscle.