6 - Lipids: Triglycerides, Phospholipids, and Sterols

lipid

the class of nutrients that do not dissolve in water like triglycerides, phospholipids, and sterols

fatty acid

the hydrocarbon chain found in lipids in which one end of the chain forms a carboxylic acid and one end forms a methyl group

hydrocarbon chain

the chain of carbon atoms bonded to each other and to hydrogen atoms

omega

the end of a fatty acid containing a methyl (—CH₃) group

carboxylic acid

the organic molecule with a carboxyl (—COOH) group

saturated fatty acid

the fatty acid that has each carbon atom within the chain filled with hydrogen atoms

unsaturated fatty acid

the fatty acid that is missing hydrogen atoms and has one or more double bonds within the carbon chain

monounsaturated fatty acid

the fatty acid that has one double bond within the carbon chains

polyunsaturated fatty acid

the fatty acid that has two or more double bonds within the carbon chain

linoleic acid

the 18-carbon polyunsaturated fatty acid with two double bonds

alpha linoleic acid

the 18-carbon polyunsaturated fatty acid with three double bonds

omega-3 fatty acid

the 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

the type of polyunsaturated fatty acid with the first double bond at the sixth carbon from the omega end of the molecule

essential fatty acid

the fatty acid that must be supplied by the diet like linoleic and alpha-linolenic acids

arachiodonic acid

the essential fatty acid that is a precursor to some eicosanoids

eicosapentaenoic acid

the essential fatty acid that is a precursor to some eicosanoids

docosahexaenoic acid

the essential fatty acid that is a precursor to some eicosanoids

eicosanoid

the group of long-chain fatty acids with hormonelike functions

prostaglandin

the class of eicosanoids that produce a variety of important effects on the body

trans fat

the unsaturated fatty acid that has a trans double bond

partial hydrogenation

the food manufacturing process that adds hydrogen atoms to liquid vegetable oil, forming trans fats

triglyceride

the lipid that has three fatty acids attached to a three-carbon compound called glycerol

glycerol

the three-carbon alcohol that forms the “backbone” of fatty acids

monoglyceride

the lipid that has one fatty acid attached to a three-carbon compound called glycerol

diglyceride

the lipid that has two fatty acids attached to a three-carbon compound called glycerol

phospholipid

the type of lipid needed to make cell membranes and for proper functioning of nerve cells

hydrophilic

describes the part of a molecule that attracts water

hydrophobic

describes the part of a molecule that avoids water and attracts lipids

emulsifier

the substance that helps water-soluble and water-insoluble compounds mix with each other

choline

the water-soluble, vitamin-like compound

cholesterol

the lipid found in animal foods; precursor for steroid hormones, bile, and vitamin D

sterol

the type of lipid that has a more complex chemical structure than triglycerides and phospholipids

plant sterol

the chemical found in plants that is structurally similar to cholesterol

lipase

the enzyme that breaks down lipids

pancreatic lipase

the digestive enzyme that removes two fatty acids from each triglyceride molecule

bile salt

the component of bile

micelle

the water-soluble, spherical lipid cluster

fat malabsorption

the impaired fat absorption

chylomicron

the type of lipoprotein formed in enterocytes to transport lipids away from the GI tract

lipoprotein

the water-soluble structure that transports lipids through the bloodstream

lipoprotein lipase

the enzyme in capillary walls that breaks down triglycerides

very-low-density lipoprotein

the lipoprotein made in the liver

low-density lipoprotein

the lipoprotein that carries cholesterol into tissues

high-density lipoprotein

the lipoprotein that transports cholesterol away from tissues and to the liver, where it can be eliminated

enterohepatic circulation

the process that recycles bile salts in the body

gallstone

the hard particle that can accumulate in the gallbladder or become lodged in one of the ducts carrying bile from the gallbladder to the small intestine

cholecystectomy

the surgery to remove a diseased gallbladder

steatorrhea

the presence of lipid in the stool

Gaucher disease

the most common lipid storage disease caused by a deficiency of an enzyme involved in lipid metabolism

cardiovascular disease

the group of diseases that affect the heart and blood vessels that includes coronary artery disease, stroke, and disease of the blood vessels

atherosclerosis

the long-term disease process in which plaque builds up inside arterial walls

arteriosclerosis

the condition that results from atherosclerosis and is characterized by loss of arterial flexibility

arterial plaque

the fatty buildup in the artery

thrombus

the fixed bunch of clots that remain in place and disrupt blood flow

myocardial infarction

a heart attack

embolus

the thrombus or part of a plaque that breaks free and travels through the bloodstream

hypertension

an abnormally high blood pressure level that persists even when the person is relaxed

homocysteine

the amino acid that may play a role in the development of atherosclerosis

homocysteinuria

the group of conditions caused by gene mutations that cause homocysteine to accumulate in the blood

oxidized LDL

the LDL that has been damaged by free radicals

adipose cell

the cell that stores triglycerides

lipoprotein profile

the series of blood tests to evaluate total cholesterol, HDL cholesterol, LDL cholesterol, and triglyceride levels

high-sensitivity C-reactive protein

the protein produced primarily by the liver in response to inflammation