Lipids Overview: Saponifiable vs Nonsaponifiable

Lipids Overview

• Lipids are categorized as saponifiable or nonsaponifiable
• Saponifiable lipids can undergo hydrolysis
• Nonsaponifiable lipids cannot undergo hydrolysis

Saponifiable Lipids

• Examples include triglycerides, phospholipids, and sphingolipids
• Simple lipids like triglycerides and waxes
• Complex lipids like phospholipids and glycolipids
• The characteristic feature of saponifiable lipids is that they contain ester linkages that can be broken down by hydrolysis in the presence of a base

Nonsaponifiable Lipids

• Steroids and prostaglandins are examples
• Lack ester bonds, making them resistant to hydrolysis

Esterification

• The process of linking an acid to an alcohol, crucial for building triglycerides
• A dehydration synthesis reaction links fatty acids to glycerol to form a triglyceride molecule

Fatty Acids

• Typically have straight chains without branching
• Carbon chain lengths usually range from 10 to 20 carbons.
• Usually contain an even number of carbons
• Can be saturated or unsaturated
• Saturated fatty acids lack double bonds, while unsaturated fatty acids contain one or more double bonds
• Saturated fats tend to have higher melting points than unsaturated fats.

Saponification

• A basic hydrolysis reaction that breaks down triglycerides
• Saponification produces soaps and glycerol

Essential Fatty Acids

• Linoleic acid and linolenic acid are examples
• Essential fatty acids cannot be synthesized by the body and must be obtained from the diet

Glycerol

• Contains a hydroxyl functional group
• This makes it an alcohol

Steroids

• Are a type of lipid.
• Often insoluble in water but soluble in nonpolar solvents

Unit Conversions

• 1 pound = 0.453592 kilograms
• 1 gram = 0.001 kilograms