Chapter 6 Terms (lipids)

Nutrition

lipids

a class of nutrients that do not dissolve in water

triglycerides

main form of fat in foods and in body stores

phospohlipids

water and fat attracting ends; build cell membranes

sterols

ring-shaped lipids, including cholesterol

-provide and store energy

-absorb fat-soluble vitamins and phytochemicals

-form and maintain cell membranes

-participate in cell signaling

-insulate against cold temperatures

-cushion against bumps and blows

-produce steroid hormones

major functions of lipids

fatty acid

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

hydrocarbon chain

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

omega (methyl) end

the end of a fatty acid containing a methly (-CH₃) group

Carboxylic acid

an organic molecule with a carboxyl (-COOH) group

Saturated (SFA)

No double bonds-every carbon filled with hydrogen

ex: butter, beef fat

monounsaturated (mufa)

one double bond in the carbon chain

ex: olive oil, canola oil

polyunsaturated (pufa)

two or more double bonds in the chain

ex: soybean oil, salmon

fats

solid at room temperature

oils

liquid at room temperature

omega 3 fatty acid

a 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

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

essiential fatty acids

fatty acids that must be supplied by the diet

cis fatty acids

most naturally occurring unsaturated fatty acids; have hydrogen atoms of the double-bonded carbons on same side of hydrocarbon chain

trans fats

unsaturated fatty acids that have at least one trans double bond

trans double bond

have hydrogen atoms of the double-bonded carbons on opposite sides of the hydrocarbon chain

triglyceride

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

glycerol

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

monoglyceride

one fatty acid attached to a glycerol

diglyceride

two fatty acids attached to glycerol

phospholipids

a 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 (and nitrogen)

hydrophilic

part of a molecule that attracts water

hydrophobic

part of a molecule that avoids water and attracts lipids

emulsifer

substance that helps water-soluable and water-insoluuable compoudns mix with each other

sterols

a type of lipid that has a more chemically complex structure than triglycerides and phospholipids; cholesterol is most well known example

cholesterol

a lipid found in animal foods; precursor for steroid hormones, bile, and vitamin D; essential to health, and the body can make its own

plant sterols and stanols

chemicals found in plants that are structurally similar to cholesterol

lipases

enzymes that break down lipids

chylomicron

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

lipoproteins

water-soluble structures that transport lipids through the bloodstream

phospholipids

cell membranes; nerve cell functioning; phosphate group and 2 fatty acid tails

lipids

class of nutrients that do not dissolve in water (fats)

sterols

ring structure; cholesterol; steroid hormones

lipids

the following are all major functions of what?

-energy

-insulate against cold

-cushion against blows

-absorb soluble vitamins and phytochemicals

-cell structure

triglycerides (adipose cells)

most lipids are stored in this form

fatty acid

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