Lipids: triglycerides, phospholipids, and sterols. Ch. 6
Micelle
Water soluble spherical lipid cluster; bile salts create a shell around each cluster, allowing for the structure to be suspended in watery digestive juices.
Choline
Water soluble, vitamin like compound; component of lecithin.
Lipoproteins
Water-soluble structure that transports lipids through the bloodstream.
Monounsaturated fatty acid (MUFA)
fatty acid that has one double bind within the carbon chains.
Major functions of lipids in the body
* provide and store energy * form and maintain cell membranes * produce steroid hormones * insulate the body against cold temperatures * cushion the body against bumps and blows * form body contours * absorb fat-soluble vitamins and photochemicals
Lipoprotein lipase (LPL)
Enzyme in capillary walls that breaks down triglycerides.
Lipases
Enzymes that break down lipids
Arachidonic acid
Essential fatty acid; precursor to some eicosanoids
Saturated fatty acid
Fatty acid that has each carbon atom with it he chain flicked with hydrogen atoms.
Polyunsaturated fatty acid (PUFA)
Fatty acid that has two or more double bonds within the carbon chain.
Unsaturated fatty acid
Fatty acid that is missing hydrogen atoms and has one or more double bones within the carbon chain.
Essential fatty acids
Fatty acids that must be supplied by the diet; linoleic and alpha-linolenic acid are essential fatty acids.
Hydrogenation
Food manufacturing process that adds hydrogen atoms to liquid vegetable oil; forming trans fats.
Fatty acid
Hydrocarbon chain found in lipids; one end of the chain forms a carboxylic acid, and one end forms a methyl group. Fatty acids provide energy for muscles and most other types of cells.
Fat malabsorption
Impaired fat absorption; symptoms include diarrhea, steatorrhea, and rapid weight loss.
Cholesterol
Lipids found in animal foods; precursor for steroid hormones, bile and vitamin D
Monoglyceride
Lipids that has one fatty acid attached to a three carbon compound called glycerol.
Triglyceride
Lipids that has three fatty acids attached to a three-carbon compound called glycerol. Compromise about 95% of lipids in food and in the human body.
Diglyceride
Lipids that has two fatty acids attached to a three carbon compound called glycerol.
Carboxylic acid
Organic molecule with a carboxyl group
Hydrophilic
Part of a molecule that attracts water
Hydrophobic
Part of a molecule that avoids water and attracts lipids.
Oleic acid
18 carbon monounsaturated fatty acid
Alpha-linolenic acid
18 carbon polyunsaturated fatty acid with three double bonds; an essential fatty acid
Linoleic acid
18 carbon polyunsaturated fatty acid with two double bonds; an essential fatty acid
Stearin acid
18 carbon saturated fatty acid
Hydrocarbon chain
Chain of carbon atoms bonded to each other and to hydrogen atoms.
Plant sterols/stanols
Chemicals found in plants that are structurally similar to cholesterol
Bike salts
Component of bile; aid in lipid digestion.
Pancreatic lipase
Digestive enzyme that removes two fatty acids from each triglyceride molecule
Omega or the methyl end
End of a fatty acid containing a methyl group
Lipid digestion and absorption
See page 161
Lipid digestion and absorption
See page 164
Emulsifier
Substance that helps water-soluble and water-insoluble compounds mix with each other
Glycerol
Three carbon alcohol that forms the backbone of fatty acids.
Sterols
Type of lipid that has a more complex chemical structure than triglycerides and phospholipids.
Chylomicron
Type of lipoprotein formed in enterocytes to transport lipids away from GI tract
Omega-3 fatty acid
Type of polyunsaturated fatty acid with the first double bond at the third carbon from the omega end of the molecule.
Omega 6 fatty acid
Type or polyunsaturated fatty acid with the first double bond at the sixth carbon from the omega end of the molecule.
Trans fats
Unsaturated fatty acids that have a trans double bond.
Lipids
class of nutrients that do not dissolve in water; triglycerides, phospholipids l, and sterols. Structural components of the plasma membrane that surrounds each cell.
Phospholipid
type of lipid needed to make cell membranes and for proper functioning of nerve cells; chemically similar to a triglyceride except that one of the fatty acids is replaced by a chemical group that contains phosphorus.
