Chapter six Lipids, Triglycerides, Phospholipids and Sterols

Lipids

Class of nutrients that do not dissolve in water; triglycerides, phospholipids, and sterols

hydrophilic

a part of a molocule that attracts water

hypertension

abnormally high blood pressure levels that persist even when the person is relaxed

homocysteine

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

Omega/ methyl end

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

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

docosahexaenoic acid (DHA)

essential fatty acid; precursor to some eicosanoids

eicosapentaenoic acid (EPA)

essential fatty acid; precursor to some eicosanoids

saturated fatty acid (SFA)

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

monounsaturated fatty acid (MUFA)

fatty acid that has one double bond within the carbon chains

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 bonds 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

arterial plaque

fatty buildup in the artery

thrombus

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

partial hydrogenation

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

homocysteinuria

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

cardiovascular disease (CVD)

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

eicosanoids

group of long-chain fatty acids with hormonelike functions

gallstones

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

myocardial infarction

heart attack

Fatty acid

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

fat malabsorption

impaired fat absorption; symptoms include diarrhea, fatty stools, and rapid weight loss

cholesterol

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

monoglyceride

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

Triglyceride

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

Diglyceride

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

very-low-density lipoprotein (VLDL)

lipoprotein made in the liver; carries much of the triglycerides in the bloodstream

low-density lipoprotein (LDL)

lipoprotein that carries cholesterol into tissues; elevated LDL is linked to increased risk of cardiovascular disease

high-density lipoprotein (HDL)

lipoprotein that transports cholesterol away from tissues and to the liver, where it can be eliminated; low HDL is linked to increased risk for cardiovascular disease

serum

liquid portion of blood that has had the cells and clotting factors removed

plasma

liquid portion of blood that has had the cells removed; contains clotting factors

atherosclerosis

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

Gaucher disease

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

carboxylic acid

organic molecule with a carboxyl (—COOH) group

hydrophobic

part of a molecule that avoids water and attracts lipids

omega-6 fatty acid

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

steatorrhea

presence of lipid in the stool

enterohepatic circulation

process that recycles bile salts in the body

high-sensitivity C-reactive protein (hs-CRP)

protein produced primarily by the liver in response to inflammation; a marker of CVD

lipoprotein profile

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

emulsifier

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

cholecystectomy

surgery to remove a diseased gallbladder

plant sterols/stanols

chemicals found in plants that are structurally similar to cholesterol

prostaglandins

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

stroke

clot blocks an artery in the brain; brain cells that are nourished by the vessel die

bile salts

component of bile; aid in lipid digestion

arteriosclerosis

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

pancreatic lipase

digestive enzyme that removes two fatty acids from each triglyceride molecule

lipoproteins

water-soluble structures that transport lipids through the bloodstream

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

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

oxidized LDL

LDL that has been damaged by free radicals

adipose (fat) cells

cells that store triglycerides

Hydrocarbon Chain

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

glycerol

three-carbon alcohol that forms the "backbone" of fatty acids

embolus

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

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

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 the 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

Trans fats

unsaturated fatty acids that have a trans double bond