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40 Cards in this Set
- Front
- Back
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... are the major components of cell membranes.
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phospholipids
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phospholipids can also be found in ..., ..., and lung ...
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lipoproteins
bile lung surfactant |
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the polyunsaturated fatty acids attached to phospholipids can serve as ... for the synthesis of eicosanoids.
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precursors
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in phospholipids, ... serves as a backbone to which fatty acids and other constituents attach
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glycerol
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The initial steps in phospholipid synthesis are similar to steps involved in the synthesis of ...
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triglycerides
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Glycerol 3-phosphate reacts with fatty acyl CoA to form ...
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phosphatidic acid
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2 different mechanisms are then used to add a ... to the carbon 3 of glycerol
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head group
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head groups are small, ... groups, usually charged or polar
-ex. choline, ethanolamine, serine, inositol |
hydrophilic
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In the first mechanism, phosphatidic acid is cleaved by a phosphatase to form diacylglycerol (DAG). DAG then reacts with an activated ...
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head group
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In the second mechanism, phosphatidic acid reacts with ..., a high energy molecule similar to ATP, to form ...
This molecue then reacts with a head group to produce a glycerophospholipid. |
CTP (cytidine 5'-triphosphate)
CDP-diacylglycerol |
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which glycerophospholipid is this?
-also known as lecithin -needed by every cell in the body and is a key building block of cell membranes -important component of the mucus layer in the large intestines -patients suffering from ulcerative colitis have a disturbed mucosal barrier, and the mucus layers in their large intestines exhibit lower levels of this than that of healthy people. |
Phosphotidylcholine
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which glycerophospholipid is this?
-found in fish, green leafy veggies, soybeans and rice -is essential for normal functioning of neuronal cell membranes -in apotosis, this is transferred to the outer leaflet of the plasma membrane. This is part of the process by which the cell is targeted for phagocytosis. -This has been used to slow cognitive decline in early-onset Alzheimer's disease |
phosphtidylserine
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what are the 2 enzymes that arrange phospholipids in membranes?
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scramblase
flippase |
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Which enzyme randomly flips phospholipids across the bilayer to evenly distribute them?
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scramblase
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which enzyme targets specific phospholipids and flips them across the bilayer?
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flippase
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sphingolipids are a component of all membranes but are particularly abundant in the ...
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myelin sheath
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... are thought of to be confusing and enigmatic
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sphingolipids
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sphingolipids can act as ... communication molecules, antigenic determinants (... blood type), and viral and bacterial ...
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intercellular
ABO receptors |
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the core of sphingolipids is the long-chain amino alcohol ... (instead of glycerol), which is derived from the AA serine.
-amino acylation with a long chain fatty acid at carbon 2 of this yields a ... |
sphingosine
ceramide |
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the synthesis of sphingolipids begins with formation of ... from serine and palmityl CoA
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ceramide
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... is the only sphingolipid that is also considered a phospholipid.
It is an important structural lipid component of nerve cell membranes. |
sphingomyelin
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The glycosphingolipids (the cerebrosides, sulfatides, globosides and gangliosides) are formed through the addition of galactose, glucose, or other ... molecules to the ceramide backbone. (They are produced by adding long carbohydrate chains)
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sugar
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levels of lecithin (phosphatidylcholine) and sphingomyelin in amniotic fluid are used to assess ...
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fetal lung development
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lecithin is the major lipid in ..., which reduces water surface tension in alveoli to prevent lungs from collapsing during exhalation.
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lung surfactant
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-levels of lecithin increase dramatically at # weeks gestation as the fetal lungs reach maturity and begin producing sufficient amounts of surfactant.
-infants born prior to this point may suffer from ... |
35
RSD (respiratory distress syndrome or hyaline membrane disease) |
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Sphingolipids are degraded by lysosomal enzymes. Deficiencies of these enzymes result in a group of lysosomal storage diseases known as the sphingolipidosis due to an inherent defect in ... degradation.
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ceramide
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These diseases all have defects in ...
tay-sachs disease gangliosidosis sandhoff disease fabry's disease gaucher's disease krabbe's disease niemann-pick disease farber's disease |
ceramide degration
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Synthesis of cholesterol occurs primarily in the ..., but also in adrenal glands, ovaries and testes (steroid producing organs)
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liver
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approximately #% of the body's cholesterol is synthesized de novo (by your cells) from acetyl CoA (the rest comes from your diet)
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80%
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Cholesterol synthesis occurs in # stages and requires significant reducing power in the form of ...
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4
NADPH |
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In the first stage, acetyl-CoA is converted into ...
-two key enzymes catalyze this conversion: HMG-CoA synthase and ... -HMG = beta-hydroxy-beta-methylglutaryl CoA |
mevalonate
HMG-CoA reductase |
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the first stage is the rate limiting step in cholesterol synthesis and is therefore the ...
what are some examples of HMG-CoA reductase inhibitors? |
major point of regulation
lovastatin/pravastatin |
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In the second stage, 3 phosphate groups are transferred from ATP to ..., forming 2 activated ... molecules.
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mevalonate
isoprene |
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In stage 3, the 6 activated 5-carbon isoprenes condense to form the 30-carbon ...
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squalene
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In the 4th stage, squalene is then converted to the 4-ring ... nucleus of cholesterol
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steroid
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SREBPs (steroid regulator element binding proteins) act as a regulatory ..., controlling expression of key enzymes involved in cholesterol metabolism
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transcription factor
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HMG-CoA reductase is
... by insulin and thyroxine and ... by glucagon and excess cholesterol |
stimulated
inhibited |
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what are these examples of?
"statins" niacin/nicotinic acid bile acid resins fibric acid derivatives |
cholesterol lowering medications
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what are the 4 main mechanisms for lipid movement?
-... diffusion -... between membrane layers -... lipid-transfer proteins -... transport carriers |
-lateral
-translocation -cytosolic -membrane-bound |
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where are lipids synthesized in the cell?
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SER
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