Chapter 5: The Lipids: Fats, Oils, Phospholipids, and Sterols

Lipid

a family of organic compounds soluble in organic solvents but not in water; includes triglycerides (fats and oils), phospholipids, and sterols

Cholesterol

a member of the group of lipids known as sterols; a soft, waxy substance, made in the body and also found in animal-derived foods

Lipid

a family of organic compounds soluble in organic solvents but not in water; includes triglycerides (fats and oils), phospholipids, and sterols

Cholesterol

a member of the group of lipids known as sterols; a soft, waxy substance, made in the body and also found in animal-derived foods

Fats

lipids that are solid in room temperature

Lecithin

a phospholipid manufactured by the liver and also found in many foods; a major constituent of cell membranes

Glycerol

an organic compound, three carbons long, of interest here because it serves as the backbone for triglycerides

Sterols

have a structure similar to that of cholesterol; rises of carbon with side chains of carbon, hydrogen, and oxygen

Cardiovascular Disease

a general term describing diseases of the heart and/or blood vessels; includes hypertension, coronary heart disease, and stroke

Satiety

the feeling of fullness or satisfaction that people experience after meals; generally determines the length of time between meals

Phospholipids

where each has a phosphorus-containing acid in place of one of the fatty acids; present in all cell membranes

Triglycerides

three fatty acids attached to glycerol molecules

Three Main Classes of Dietary Lipids

Sterols, Phospholipids, and Triglycerides

Fatty Acids

organic acids are composed of carbon chains of various lengths; they have an acid end and hydrogens attached to all of the carbon atoms of the chain

Essential Fatty Acids

where the body needs the fatty acids but cannot be obtained from the diet

Oils

lipids that are liquid at room temperature

Unsaturated Fatty Acids

a fatty acid that lacks some hydrogen atoms and has one or more points of unsaturation; a triglyceride that contains one or more from it

Point of Unsaturated

a site in a molecule where the bonding is such that additional hydrogen atmos can easily be attached

Saturated Fats/Fatty Acids

a fatty acid carrying the maximum possible number of hydrogen atoms (no unsaturation), a triglyceride with three fatty acids

Monosaturated Fats/ Fatty Acid

a fatty acid containing one point of unsaturation

Homogenization

a process by which milk fat is evenly dispersed within fluid milk; under high pressure, milk is passed through tiny nozzles to reduce the size of fat droplets and reduce their tendency to cluster and float to the top as cream

Polyunsaturated Fats/Fatty Acids

triglycerides in which most of fatty acids have two or more points of unsaturation

Shortening

a semisolid fat made from vegetable oil commonly used for frying foods, or in baked goods to achieve a “short,” or flaky, texture

Trans Fats

fat that contains any number of unusual fatty acids (formed during processing)

Emulsion

a mixture of two lipids that do not usually mix, in which tiny particles of one liquid are held suspended in the other

Atherosclerosis

a disease of the arteries characterized by lipid deposits known as plaques along the inner walls of the arteries; a major cause of CVD

Lipoproteins

clusters of lipids associated with protein, which serve as transport vehicles for lipids in blood and lymph; include chylomicrons, VLDL, LDL, and HDL

Emulsification

the process of mixing lipid with water by adding an emulsifier

Monoglycerides

products of the digestion of lipids; a glycerol molecule with one fatty acid

Chylomicrons

lipoproteins formed when lipids form a meal cluster with carrier proteins in the cells of the intestinal lining; transport food fats through the watery body fluids to the liver and other tissues

Subcutaneous

located beneath the skin

Linoleic Acid

an essential polyunsaturated fatty acid of the omega-6 family

Trans-Fatty Acids

contains unusual shape that can arise when hydrogens are added to the unsaturated fatty acids of polyunsaturated oils

Arachidonic Acid

an omega-6 fatty acid derived from linoleic acid

Omega-6 Acid

a polyunsaturated fatty acid with its endmost double bond six carbons from the end of the carbon chain

Very-Low-Density Lipoproteins (VLDL)

lipoproteins that transport triglycerides and other lipids from the liver to various tissues in the body

High-Density Lipoproteins (HDL)

lipoproteins that return cholesterol from the tissues to the liver for dismantling and disposal; contain a large proportion of protein

Linolenic Acid

an essential polyunsaturated fatty acid of the omega-3 family

Inflammation

an immune response to cellular injury that produces an increase in white blood cells, redness, heat, pain, and swelling. a chronic one accompanies many diseases

Eicosanoids

biologically active compounds that regulate body functions

Low-Density Lipoproteins (LDL)

transport lipids from the liver to other tissues, such as muscle and fat; contain a large proportion of cholesterol

EPA and DHA

eicosapentaenoic/docosahexaenoic acid; omega-3 fatty acids made from linolenic acid in the tissues of fish

Omega-3 Fatty Acid

a polyunsaturated fatty acid with its endmost double bond three carbons from the end of the carbon chain

Artificial Fats

zero-energy fat replacers that are chemically synthesized to mimic the sensory and cooking qualities of naturally occurring fats but that are totally or partially resistant to digestion

Methylmercury

any toxic compound of mercury to which a characteristic chemical structure, a methyl group, has been added, usually by bacteria in aquatic sediments; readily absorbed from the intestine and causes nerve damage in people

Hydrogenation

the process of adding hydrogen to unsaturated fatty acids to make fat more solid and resistant to the chemical change of oxidation

Oxidation

interaction of a compound with oxygen; in this case, a damaging effect by a chemically reactive form of oxygen

Fat Replacers

ingredients that replace some or all of the functions of fat and may or may not provide energy

Stearic Acid

an 18-carbon saturated fatty acid found in most animal fats, intake increases heart risks, but does not raise blood LDL cholestrol

Smoking Point

the temperature at which fat gives off an acrid blue gas

Palmitic Acid

a 16-carbon saturated fatty acid found in tropical palm oil, among other foods; raises LDL cholesterol, increase CVC risk, and is associated with a dangerous form of irregular heartbeat