Term
what do all membrane lipids contain?
which lipids do all body tissues synthesize? with which exception?
where are the enzymes for synthesis of these lipids? |
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Definition
they all contain fatty acids
phosphoglycerides & sphingolipids
except RBC don't synthesize lipids
the enzymes are found in the cytosol & on the membrane |
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Term
what's the typical composition of a phospholipid? |
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Definition
fatty acid tail + head group |
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Term
what's the precursor to phospholipids?
where does the energy come from for the synthesis? |
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Definition
precursor - DHAP (dihydroxy acetone phosphate)
energy - from cytidine triphosphate
(instead of adenosine triphosphate, ATP) |
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Term
what can be used to make phosphatidylcholine?
what is needed to convert it? |
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Definition
phosphatidylserine
PL D enzyme & SAM |
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Term
what's the only antigenic phospholipid? |
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Definition
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Term
where is dipalmitoylphosphatidylcholine (DPPC) found?
what makes it & secretes it?
what disease is associated with it?
so how can we test for this disease?
how do we know if it's not present? |
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Definition
it's a component of lung surfactant
made by pneumocytes
respiratory distress syndrome - no surfactant in infant
test for it by measuring the DPPC to S(sphingomyelin) ratio
A ratio of 2 or above means maturity
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Term
where is phospholipase C used?
what is the function of the products? |
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Definition
in second messenger pathway
it cuts IP2 into:
DAG -> (protein kinase C)
IP3 -> (Ca2+ release) |
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Term
1. what is phospholipase A2 used for?
2. what's the function of the products?
3. what's A2's second use?
4. what then fixes the problem?
5. what is A2 inhibited by?
6. where is alot of A2 found? |
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Definition
1. it releases arachadonic acid for thromboxane & 2. prostaglandin synthesis
3. repair mechanism for distorted lipids in membranes (cuts out the bad ones)
4. Acyltransferase adds new FA
5. glucocorticoids inhibit it
6. pancreatic excretions are rich in 'em |
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Term
what makes platelet activating factor water soluble?
what is it and what does it stimulate?
what effect does this have?
what effect does it have on neutrophils? |
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Definition
an acetyl group attached to it
it's a hormone that binds to platelet receptors
it causes their aggregation resulting in thrombotic & inflammatory events
causes neutrophils etc. to make superoxide radicals |
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Term
where are phosphatidylethanolamine & phosphatidylcholine found mostly?
what category do they fall under?
what disease are these associated with? |
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Definition
ethanolamine - nerve tissue
choline - heart muscle
they are both plasmalogens
associated with Alzheimer's disease |
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Term
what two compounds are the complex lipids synthesized from? |
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Definition
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Term
what are gangliosides ?
where are some of them found?
what else do they determine? |
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Definition
complex sphingolipids with large polar head groups
6% in grey matter of brain
determine blood groups |
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Term
what determines the different blood groups?
which enzyme determines A / B groups? |
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Definition
the sugar that's attached to a ganglioside.
A - N-acetylgalactosamine transferase
B - Galactose transferase |
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Term
Tay-Sachs disease
enzyme deficient?
accumulating substance?
symptoms? |
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Definition
Hexoaminidase A
GM2 ganglioside
mental retard
blind
muscle weakness / seizures |
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Term
Gaucher disease
enzyme deficiency?
accumulating substance?
symptoms? |
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Definition
Glucocerebrosidase
Glucocerebroside
hapatosplenomegaly
mental retardation
osteoperosis of long bones
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Term
Fabry disease
what's unique about this disease?
enzyme deficiency?
accumulating substance?
symptoms? |
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Definition
the only x-linked disease
α-galactosidase
Globosides
kidney / heart failure
red-purple skin rashes
burning pain in lower extremeties |
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Term
Krabbes disease
enzyme deficiency?
accumulating substance?
symptoms? |
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Definition
B-galactosidase
galacto-cerebroside
mental/motor deterioration
blind/deaf
loss of myelin in white matter of brain |
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Term
how do you test for disorders of sphingolipid metabolism? |
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Definition
extract lisosomal enzymes (specific for what disease you're testing for)
then add the compound they are supposed to break up.
if only half of it gets broken up, the person is a heterozygote for the disease etc. |
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