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18 Cards in this Set
- Front
- Back
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Lipids do not form...
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...Polymers
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Lipids do not form Polymers therefore...
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Low melting point, Usually liquid.
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Lipids: Composed of which elements?
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Carbon, Oxygen and Hydrogen
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Test for lipids:
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Emulsion Test
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The term lipid covers:
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Fats (solid) and Oils (liquid)
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Lipids are composed of:
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Fatty Acids and Glycerol
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R is used in chemical diagrams to ...
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...indicate a hydrocarbon chain of variable length
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Typically fatty acids will have between...
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...16-18 carbons in their R group
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Fatty acids are polar molecules...
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...the COOH group is attracted to water (hydrophillic) and the hydrocarbon chain is repelled by water (hydrophobic)
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The most common form of lipid molecule
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is the triglyceride
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Triglycerides are composed of
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one glycerol molecule with three attached fatty acid molecules
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If there are no C=C double bonds in the hydrocarbon chain of a fatty acid,
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then the fatty acid is saturated
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These fatty acids form straight chains which pack together fairly well,
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so make lipids with a reasonably high melting point.
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If there are C=C double bonds in the hydrocarbon chain of a fatty acid,
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then the fatty acid is unsaturated
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Fatty acids with more than one double bond are called
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poly-unsaturated fatty acids.
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Phospholipids have a similar structure to triglycerides, but instead of having three fatty acids attached to the glycerol they have...
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...two fatty acids and one phosphate group
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Phospholipids have
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a polar hydrophilic "head" (the phosphate group) and two non-polar hydrophobic "tails" (the fatty acid chains).
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This polarity is what helps phospholipids form...
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...stable bilayers in aqueous solutions and these bilayers form the basis of plasma membranes.
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