Chapter 23.3, Problem 17SSC

Interpretation Introduction

Interpretation:

The structures of a steroid, a phospholipid and a wax should be compared and contrast.

Concept introduction:

The molecules which contains hydrocarbons and not soluble in water but soluble in nonpolar solvents is known as lipid.

Lipids are classified as:

Triglycerides, Phospholipids and, Steroids and Waxes

Explanation of Solution

General structure of phospholipids contains a glycerol molecule(s), phosphate group and two fatty acids. The type of lipid which is the main component of cell membrane is known as phospholipid. Phospholipid consists of two fatty acids and a phosphate group.

In the structure of Phospholipid, two fatty acids and a phosphate group linked with each other by ester bonds.

The general structure of phospholipid is:

General structure of steroid contains 17 carbon atoms which are linked with each other in four fused rings, three rings contains six carbon atoms that is cyclohexane rings and one is five membered ring that is cyclopentane.

The four ring structure of steroid is:

A simple lipid consists of an ester of a long chain alcohol and fatty acid is known as wax. The alcohol present in a wax consists of 12-32 carbon atoms. The reaction between an alcohol and fatty acid results in the formation of wax having ester bond.

The reaction is:

The structure of wax is: