Chapter 15, Problem 15.58AP

(a)

Interpretation Introduction

Interpretation:

Structure of lecithin that contains two molecules of oleic acid has to be drawn.

Concept Introduction:

Lipids that contain phosphorus atoms are called phospholipids. The common type of phospholipid that is phosphoacylglycerol consists of phosphate group is attached to third oxygen atom that is further attached to an alkyl group $\left({\text{R}}^{″}\right)$. The alkyl group is generally derived from alcohol that makes it different from triacylglycerol. The difference in ${\text{R}}^{″}$ give two types of phosphoacylglycerol that are as follows:

Cephalin is a type of a phosphoacylglycerol in which phosphate group is attached to an alkyl group $\left({\text{R}}^{″}\right)$. The general structure of cephalin is as follows:

Here, $\text{R}$ and ${\text{R}}^{\prime }$ are alkyl groups of fatty acids and ${\text{R}}^{″}$ is $-\text{O}-{\text{CH}}_2{\text{CH}}_2{\text{NH}}_3^{+}$.

(b)

Interpretation Introduction

Interpretation:

Structure of cephalin that contains two molecules of myristic acid has to be drawn.

Concept Introduction:

Refer to part (a).