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24 Cards in this Set
- Front
- Back
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definition of a lipid
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small, water insoluble molecule that is soluble in organic non-polar solvents
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2 major roles of lipids
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-major structural component of membranes
-major store of energy |
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what are the two classes of lipids
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-simple lipids (don't contain fatty acids, like cholesterol).
-complex lipids (do contain fatty acids, like TAG's and Phosphatides |
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What type of bond links fatty acids to complex lipids?
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ester or amide links
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what types of cells are TAG's in?
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ADIPOSE - fat cells
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what is the role of Phosphatides?
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MEMBRANE lipid components
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what is the backbone of
-TAGs -Phosphatides |
GLYCEROL!
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what is the backbone of
-TAGs -Phosphatides |
GLYCEROL!
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what does a TAG consist of?
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-Glycerol backbone
-3 Fatty acid tails |
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What does a Phosphatide consist of?
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-Glycerol backbone
-2fatty acid tails -Phosphate! |
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what does the term amphipathic refer mean, and what does it refer to?
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the fact that phospholipids are both polar and nonpolar in different areas.
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what are the two major components of a BIOMEMBRANE?
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proteins and lipids
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what percentage of lipid structure is composed of carbohydrates, and in what two forms?
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2 to 10%
-Glycolipids -Glycoproteins |
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What are glycolipids
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Sugar-containing lipids.
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What 3 kinds of membranes have varied proportions of lipids/proteins?
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-protein-rich: mitochondrial (proton pumps)
-lipid-rich: myelin sheath - neurons - very insulating. -equal parts: like plasma membrane |
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what is the percentage composition of a myelin membrane?
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LIPID RICH
75% lipid 25% protein |
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what is the percentage comp. of inner mitochondrial membrane?
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-PROTEIN RICH
-75% protein -25% lipid |
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what type of membrane has equal parts lipid/protein
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plasma membrane (cell membranes!!!)
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what types of lipids are often zwitterions?
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-PHOSPHITIDATES - cuz they have the alcohol component, which can be from like a serine or amino acid.
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what types of aggregates do
-fatty acids form -phosphatidates form |
-micelles
-lipid bilayers |
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2 Ways proteins associate with lipid bilayer:
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-Integral proteins
-peripheral proteins |
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What does the Fluid Mosaic Model propose:
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proteins diffuse within plane of the lipid bilayer but do not flip in it.
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what is the role of peripheral proteins?
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attach to lipid bilayer surface:
-noncovalent bond to integral proteins or -lipid tether |
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what is the role of integral proteins
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most extend all the way through the membrane. make contact with hydrophobic interior of membrane.
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