Integrated Web Site to Accompany Discovering Nutrition, Second Edition

Lipids are a broad range of molecules that dissolve easily in organic solvents, but are much less soluble in . They are generally hydrophobic and lipophilic. The three main types of lipids are triglycerides, phospholipids, and sterols. are the largest category of lipids and are stored in the body in . are major building blocks of cell membranes. They keep fats suspended in watery fluids. The most famous sterol, cholesterol, is manufactured in the body and is a precursor to the synthesis of sex hormones, and vitamin D. Lipids share many of the same functional properties and transport mechanisms.

are common components of triglycerides and phospholipids. There are many types of these substances, which are basically chains of atoms with a carboxyl group on one end and a methyl group at the other end. Short chain fatty acids have less than carbons; medium chains have 6-10; and long chains have or more. The water-soluble property of shorter fatty acids affects their absorption.

A triglyceride is made of fatty acids attached to a glycerol molecule. Triglycerides are esters which form when a hydrogen and an oxygen from the carboxyl group combine with a hydrogen atom from the alcohol’s hydroxyl group. A molecule of water is produced which makes this a reaction.