Basic Nutrition - Chapter 5

Omega-6 Fatty Acid

A fatty acid containing a carbon-carbon double bond between the sixth and seventh carbons from the omega end; includes linoleic and arachidonic acid.

Omega-3 Fatty Acid

A fatty acid containing a carbon-carbon double bond between the third and fourth carbons from the omega end; includes alpha-linolenic acid found in vegetable oils and EPA found in fish oils.

Monounsaturated Fatty Acid

A fatty acid containing one carbon-carbon double bond.

Saturated Fatty Acid

A fatty acid in which the carbon atoms are bonded to as many hydrogen atoms as possible; it therefore contains no carbon-carbon double bonds.

Unsaturated Fatty Acid

A fatty acid that contains one or more carbon-carbon double bonds; may be either monounsaturated or polyunsaturated.

Polyunsaturated Fatty Acid

A fatty acid that contains two or more carbon-carbon double bonds.

Essential Fatty Acids

A fatty acid that must be consumed in the diet because it cannot be made by the body or cannot be made in sufficient quantities to meet the body's need.

Alpha-Linolenic Acid

An 18-carbon omega-3 polyunsaturated fatty acid known to be essential in humans.

Lipoprotein Lipase

An enzyme that breaks down triglycerides into free fatty acids and glycerol; attached to the outside of the cells that line the blood vessels.

Linoleic Acid

An omega-6 essential fatty acid with 18 carbons and 2 carbon-carbon double bonds.

Trans Fatty Acids

An unsaturated fatty acid in which the hydrogens are on opposite sides of the carbon-carbon double bond.

Cardiovascular Disease

Any disease affecting the heart and blood vessels.

Eicosapentaenoic Acid (EPA)

A 20-carbon omega-3 polyunsaturated fatty acid found in fish that can be synthesized from alpha-linolenic acid but may be essential in humans under some conditions.

Arachidonic Acid

A 20-carbon omega-6 polyunsaturated fatty acid that can be synthesized from linoleic acid.

Docosahexaenoic Acid (DHA)

A 22-carbon omega-3 polyunsaturated fatty acid found in fish that may be needed in the diet of newborns. It can be synthesized from alpha-linolenic acid.

Phosphate Group

A chemical group consisting of one phosphorus atom and four oxygen atoms.

Foam Cells

A cholesterol-filled white blood cell.

Lipids

A class of nutrients that is commonly called fats. Chemically, they contain carbon, hydrogen, and oxygen, and most of them do not dissolve in water. They include fatty acids, triglycerides, phospholipids, and sterols.

Plant Sterol

A compound found in plant cell membranes that resembles cholesterol in structure. It can lower blood cholesterol by competing with cholesterol for absorption in the gastrointestinal tract.

Essential Fatty Acid Deficiency

A condition characterized by dry, scaly skin and poor growth that results when the diet does not supply sufficient amounts of linoleic acid and alpha-linolenic acid.

Monoglyceride

A glycerol molecule with one fatty acid attached.

Very-Low-Density Lipoprotein

A lipoprotein assembled by the liver that carries lipids from the liver and delivers triglycerides to body cells.

High-Density Lipoprotein (HDL)

A lipoprotein that picks up cholesterol from cells and transports it to the liver so that it can be eliminated from the body.

Low-Density Lipoprotein (LDL)

A lipoprotein that transports cholesterol to cells.

Chylomicron

A lipoprotein that transports lipids from the mucosal cells of the small intestine and delivers triglycerides to other body cells.

Fatty Acid

A molecule made up of a chain of carbons linked to hydrogens, with an acid group at one end of the chain.

Micelle

A particle that is formed in the small intestine when the products of fat digestion are surrounded by bile. It facilitates the absorption of lipids.

Lipoprotein

A particle that transports lipids in the blood.

Lecithin

A phosphoglyceride composed of a glycerol backbone, two fatty acids, a phosphate group, and a molecule of choline; often used as an emulsifier in foods.

Hydrogenation

A process whereby hydrogen atoms are added to the carbon-carbon double bonds of unsaturated fatty acids, making them more saturated.

Inflammation

A protective response to injury or destruction of tissues; signs of acute inflammation include pain, heat, redness, swelling and loss of function.

LDL Receptor

A protein on the surface of cells that binds to LDL particles and allows their contents to be taken up for use by the cell.

Cholesterol

A sterol, produced by the liver and consumed in the diet, which is needed to build cell membranes and make hormones and other essential molecules.

Oxidized LDL Cholesterol

A substance formed when the cholesterol in LDL particles is oxidized by reactive oxygen molecules. It is key in the development of atherosclerosis because it is taken up by scavenger receptors on white blood cells.

Antioxidant

A substance that decreases the adverse effects of reactive molecules. Decrease the oxidation of LDL cholesterol and, therefore, the development of plaque in artery walls.

Emulsifier

A substance with both water-soluble and fat-soluble portions that can break fat into tiny droplets and suspend it in a watery fluid.

Tropical Oils

A term used in the popular press to refer to the saturated plant oils - coconut, palm, and palm kernel oil - that are derived from plants grown in tropical regions.

Atherosclerosis

A type of cardiovascular disease that involves the buildup of fatty material in the artery walls.

Phospholipid

A type of lipid whose structure includes a phosphorus atom

Sterol

A type of lipid with a structure composed of multiple chemical rings.

Macrophage

A type of white blood that ingests foreign material as part of the immune response to foreign invaders such as infectious microorganisms.

Atherosclerotic Plaque

Cholesterol-rich material that is deposited in the arteries of individuals with atherosclerosis.

Eicosanoids

Regulatory molecules that can be synthesized from omega-3 and omega-6 fatty acids.

Triglycerides

The major type of lipid in food and the body, consisting of three fatty acids attached to a glycerol molecule.

Adipose Tissue

Tissue found under the skin and around body organs that is composed of fat-storing cells.

Lipid Bilayer

Two layers of phosphoglyceride molecules oriented so that the fat-soluble fatty acid tails are sandwiched between the water soluble phosphate-containing heads.