GLOSSARY

Neutral Lipids usually refers to nonpolar storage-type lipids such as triglycerides and cholesteryl esters; neutral does not mean inactive or calorie-free.

A polar region interacts more readily with water, whereas a nonpolar region avoids it; molecules with both are amphipathic. This enables lipid surfaces and membranes to form. Having no net charge does not necessarily mean being nonpolar: some phospholipid heads carry both positive and negative charges and remain strongly polar overall.

Triacylglycerol is the main form of stored fat energy in adipose tissue and part of the intracellular muscle reserve. Storage fat is not cholesterol or a cell membrane, although all belong to the lipid family. Fatty-acid movement into and out of stores is dynamic; pool size alone does not reveal current fuel use.

In cholesteryl ester, a fatty acid is attached to cholesterol's hydroxyl group, making it more hydrophobic and suitable for lipoprotein cores. Free cholesterol here means unesterified, not necessarily freely dissolved without a carrier in blood. Esterification is also not the same as removing cholesterol from the body or converting it into triglyceride.