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31 Cards in this Set
- Front
- Back
Describe characteristics of Lipids?
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Not polymeric, do aggregate, exhibit greater structural variety, largely hydrophobic, sparingly water soluble
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What are the three major cellular functions of Lipids?
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- Cellular Membranes
- Energy stores when containing hydrocarbon chains -Intra and Inter cellular signaling events |
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What are the classification groups of lipids?
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Fatty Acids, Triglycerides, Phosphoglycerides, Sphingolipds, Steroids, other lipids
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Describe Fatty Acids.
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They are carboxylic acids with long chain hydrocarbon side groups
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Describe Triglycerides.
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Fatty Acid esters of glycerol, energy reservoirs
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Describe Phosphoglycerides.
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biological membrane lipid
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Sphingolipids -
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Also major membrane lipid
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Describe Steroids.
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Mostly of eukaryotic origin, derivatives include sex hormones and cholesterol
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What are included in other lipids?
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Vitamins and cofactors
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What are hte predominant fatty acid residues? Which ones are uncommon?
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C16 and C18; <C14 and >C20
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Over half fatty acids are _______.
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unsaturated. Often polyunsaturated
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Where is the first double bond usually in fatty acid?
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between C9 and C10 counting from Carboxylic Acid C atom
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In polyunsaturated fatty acids. Double bond tends to occur at every _____ Carbon atom.
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Third
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What are two important classes of polyunsaturated fatty acids based on nomenclature?
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w-3 fatty acids and w-6 fatty acids; w(omega) end of chain
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How are linoleic acid and alpha linoleic acid different?
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alpha linoleic acid is w-3, and linoleic acids is w-6
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Describe saturated fatty acids.
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They are fully reduced or saturated with H, highly flexible with wide range of conformations, relatively free rotation around C-Cbonds
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Why are unsaturated fatty acids less rotational?
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Double bonds are almost always cis so this puts rigid 30 degree bend in Hydrocarbon chain
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________fatty acids pack together than _____________.
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Saturated, unsaturated
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Where are triglycerides found?
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Fats and oil in plants and animals
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Describe triglycerides.
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They are non-polar water insoluble fatty acid triesters of glycerol and serve as energy stores.
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What is the most abundant class of lipids?
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Triglycerides
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How do triglycerides differ?
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According to identity and placement of fatty acids on glycerol
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How are triglycerides named?
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Placement of glycerol moiety, ate fatty acid ending replaced by oyl ending, use 1,2,3 to indicate position
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Describe difference between plant oils and animal fats.
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Plant oils tend to be unsaturated with lower melting point while fats tend to be more saturated with higher melting points. Fats are solids at room temp and oils are liquid at room temp.
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How are fats so efficient in metabolic energy storage?
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They yield more energy/unit mass on oxidation. Storeod as anhydrous form whereas glycogen binds 2times weight of water. It provides 6 times metabolic energy as equal weight hydrated glycogen.
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What are adipocytes?
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Fat cells specialized for synthesis and storage of triacylglycerols
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Where is adipose tissue?
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Most abundant in subcutaneous layers and abdominal activity
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What is major lipid component of biological membranes?
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Glycerophospholipids
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Why are glycerophospholipids considered amphiphilic?
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They have nonpolare aliphatic hyderocarbon tails and polar phosphorylX heads
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For glycerophospholipds, where are most common head groups derived from?
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Polar alcohols
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What glycerophospholipid is an important lung surfactant?
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Lecithin
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