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15 Cards in this Set
- Front
- Back
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Lipids
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Fats, oils, and waxes
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Lipids
5 Classes |
Fatty acids
Eicosanoids Glycerides Phospholipids Glycolipids Steroids |
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Lipids
3 Main Groups |
Simple
Compound Derived |
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Lipids
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Relatively complex molecules
Make up 40% of the composition of a cell's plasma membrane Made up of an alcohol and fatty acid - is an ester |
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lipids
Properties |
Soluble in organic solvents such as alcohol, ether, acetone, and carbon tetrachloride
Contain carbon, hydrogen, oxygen, and sometimes nitrogen and phosphorus Yield fatty acids upon hydrolysis Organic Take part in plant and animal metabolism |
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Simple Lipids
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Esters of fatty acids
Simple Lipid + H2O Fatty acid and alcohol If the alcohol is glycerol, the lipid is a fat If the alcohol is something other than glycerol, the lipid is a wax Fats and Waxes are esters; not all esters are fats |
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Fatty acids
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Aliphatic molecules
Long hydrocarbon chains Free fatty acids (FFA) is fatty acids not attached to glycerol; they are toxic |
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Unsaturation and Iodine Number
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Iodine reacts with unsaturated lipids, but not with saturated lipids
The iodine number of a fat is the number of grams of iodine that will react with the double bonds present in 100 grams of fat or oil The hight=er the iodine number, the more double bonds present and the greater the degree of unsaturation In general, fats have an iodine number below 70%% and oils above 70% Below 70% is considered saturated and above 70% is unsaturated |
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Saturated Fats
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Rule of Thumb:
Fats that are solid at room temp are saturated Lipids that are liquid at room temp (oils) are unsaturated A short carbon chain and unsaturation reduce meltig points the less number of H per carbon chain, the less dense the molecule and easier to break down |
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Triglycerides
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Stored in fat cells (adipocytes)
Fat storage in adults is in white fat (as opposed to brown fat) White fat is less vascular than brown fat |
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Eicosenoids
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From the Greek meaning 20
these lipid molecules contain 20 carbons Derived from arachiconic acid - a fatty acid |
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Eicosenoids
2 major Classes |
Leukotrienes - produced by cells in the immune system respodnding to disease
Prostaglandins - short chain fatty acids, where 5 of the carbons are joined in a ring Prostaglandins are local hormones Prostaglandin, thromboxane, produced by platelets, helps in clotting |
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Compound Lipids
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These are acyl glycerols that have fatty acids and other molecules attached to them
Ex: Phospholipids |
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Phospholipids
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Hydrolysis yields fatty acids, glycerol, a nitrogen compound (choline or amino) and a phosphate containing compound (phosphatidic acid)
May also be called a phosphoglyceride Amphiphatic molecules with a polar hydrophilic head |
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Phospholipids
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Choline Phospholipid - phosphatidyl choline - a lecithin that is the exterior portion of the lipid bilayer
Amino phospholipids - phosphatidyl serine, phosphatidyl ethanolamine, phosphatidyl inositol - also known as cephalins |
