Understanding nutrition chapter 5

Lipids

a family of compounds that includes Triglycerides, Phospolipids, and sterols. Lipids are characterized by their insolubility in water

Fatty acid

an organic compound composed of a carbon chain with hydrogens attached and an acid group (COOH) at one end and a methyl group (CH3) at the other end

Monounsaturated fatty acid

a fatty acid that lacks two hydrogen atoms and has one double bond between carbons

Point of saturation

the double bond of a fatty acid where hydrogen atoms can easily be added to the structure

Polyunsaturated fatty acid

a fatty acid that lacks 4 or more H atoms & has 2 or more double bonds between C's (Ex: linoleic acid (2 double bonds) and Linolenic acid (3 double bonds)

Saturated fatty acid

a fatty acid carrying the maximum possible number of Hydrogen atoms

Unsaturated Fatty acid

a fatty acid the lacks hydrogen atoms and has at least one double bond between carbons

Linoleic acid

an essential fatty acid with 18 carbons and two double bonds.

Linolenic acid

an essential fatty acid with 18 carbons and three double bonds

Omega

used by chemists to refer to the position of the first double bond from the methyl (CH3) end of a fatty acid.

Omega-3 fatty acid

a polyunsaturated fatty acid in which the first double bond is three carbons away from the methyl (CH3) end of the carbon chain

Omega-6 fatty acid

a polyunsaturated fatty acid in which the first double bond is 6 carbons away from the methyl (CH3) end of the carbon chain

Triglycerides

the chief form of fat in the diet and the major storage form of fat in the body. Composed of a molecule of glycerol with three fatty acids attached. tri - three, glyceride - of glycerol, acyl - a carbon chain.

Glycerol

an alcohol composed of a three carbon chain which can serve as the backbone for a triglyceride. ol-alcohol

Oxidation

the process of a substance combining with oxygen. Oxidation reactions involve the loss of electrons.

Antioxidants

as a food additive, preservatives that delay or prevent rancidity of fats in foods and other damage to food caused by oxygen

Hydrogenation

a chemical process by which hydrigens are added to monounsaturated or polyunsaturated fatty acids to reduce the number of double bonds. Making fat more saturated (solid) and more resistant to oxidation. Produces trans-fatty acids.

Trans-fatty acids

fatty acids with hydrogens on opposite sides of the double bond.

Conjugated linoleic acid

several fatty acids htat have the same chemical formula as linoleneic acid (18 carbons, 2 double bonds) but with different configurations

Phospholipid

a compound similar to a triglyceride but has a phosphate group and choline in place of the fatty acid

Lecithin

Phospolipid. Both nature and the food industry use it as an emulsifier to combine water-soluble and fat-soluble ingredients that do not usually mix.

Choline

a nitrogen- containing compound found in foods and made in the body from the amino acid methionine. Its a phospohilid lecithin and the neurotransmitter acetylcholine

Sterols

compounds containing a 4 ring carbon structure with any of a variety of side chains attached.

Cholesterol

one of the sterols containing a 4 ring carbon structure with a carbon side chain. made in the liver

Atherosclerosis

a type of artery disease characterized by plaque on the inner walls of the arteries. When the arteries that carry blood to the heart muscle become blocked CHD forms.

Hydrophobic

water fearing

Hydrophilic

water loving

Monoglycerides

molecules of glycerol with one fatty acid attached.

Diglycerides

a molecule of glycerol with 2 fatty acids attached.

Micelles

tiny spherical complexes of emulsified fat that arise during digestion; most contain bile salts and the products of lipid digestion including fatty acids monoglycerides, and cholesterol.

Chylomicrons

the class of lipoproteins that transport lipids from the intestinal cells to the rest of the body

Lipoproteins

protein and fat clusters that transport fats in the blood

VLDL

very low density lipoprotein - made primarily by liver cells to transport lipids to various tissues in the body. Composed of triglycerides

LDL

low-density lipoprotein - derived from very low density lipoproteins as VLDL are removed and broken down. Composed of cholesterol. Very bad!

HDL

high density lipoprotein - transports cholesterol back to liver from the cells. Composed of proteins. "Garbage truck

Essential fatty acids

fatty acids needed by the body but not made by it in good enough amounts

Arachidonic acid

an omega-6 polyunsaturated fatty acid with 20 carbons and 4 double bonds.

Eicosapentaenoic acid

an omega-3 fatty acid with 20 carbon atoms and 5 double bonds

Docosahexaenoic acid

DHA - an omega-3 fatty acid with 22 carbon atoms and 6 double bonds

Eicosanoids

Derived from arachidonic acid (a 20 carbon fatty acid); controls several body systems and functions in immunity, inflammation, and serves as messengers in the CNS

Adipose tissue

fat tissue. consists of masses of triglyceride storing cells

Lipoprotein lipase

LPL- an enzyme that hydrolyzes triglycerides passing by in the blood stream and directs their parts into the cells where they can be metabolized for energy or reassembled for storage.

Hormone-sensitive lipase

an enzyme inside adipose cells that responds to the body's need for fuel by hydrolyzing triglycerides so that their parts (glycerol and fatty acids) escape into the general circulation and thus become available to other cells for fuel. The signals to which this enzyme responds include epinephrine and glucagon, which oppose insulin.

Blood lipid profile

results of blood tests that reveal a person's total cholesterol, triglycerides, and lipoproteins.

Cardiovascular disease

a general term for all diseases of the heart and blood vessels

Fat replacers

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

Artificial fats

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

Olestra

a synthetic fat made from sucrose and fatty acids. Provides 0 kcals per gram.