Chapter 15, Problem 15.57AP

(a)

Interpretation Introduction

Interpretation:

Structure of cephalin formed from two molecules of palmitoleic acid has to be drawn.

Concept Introduction:

Lipids that contain phosphorus atoms are called phospholipids. The common type of phospholipid is phosphoacylglycerol. It consists of a phosphate group that is attached to third oxygen atom and 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 and lecithin are a type of a phosphoacylglycerols in which phosphate group is attached to an alkyl group $\left({\text{R}}^{″}\right)$. The general structure of cephalin and lecithin is as follows:

Here, $\text{R}$ and ${\text{R}}^{\prime }$ are alkyl groups of fatty acids and ${\text{R}}^{″}$ is $-\text{O}-{\text{CH}}_2{\text{CH}}_2{\text{NH}}_3^{+}$ for cephalin and $-\text{O}-{\text{CH}}_2{\text{CH}}_2\text{N}{\left({\text{CH}}_3\right)}_3^{+}$ for lecithin.

(b)

Interpretation Introduction

Interpretation:

Structure of lecithin formed from two molecules of lauric acid has to be drawn.

Concept Introduction:

Refer to part (a).