Principles of Biochemistry

2.1.3.2 Lipids

Lipids refer to substances such as fats and oils and fat like substances present in food. They are another group of major molecules found in all cells. Lipids exhibit greater structural variety than the other classes of biological molecules. 

 

Functions: In the form of lipid bilayers they are essential components of biological membranes. Lipids containing hydrocarbon chains serve as energy stores. Many intra-and intercellular signaling events involve lipid molecules. In addition to triglycerides, cholesterol and phospholipids provide structure to the body cells.

 

Sources: Important animal sources of fat are meat, milk, eggs and fish and important plant sources are all oils and vanaspathy.  Fats from animal  sources are relatively rich in saturated fatty acids but contain a low content of polyunsaturated acids. Plant fats and fish are rich in polyunsaturated fatty acids.

Cholesterol is present in significant amounts in animal products, such as egg yolk, butterfat, and meat. It is absent in plant foods.