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?
they all contain fatty acids
phosphoglycerides & sphingolipids
except RBC don’t synthesize lipids
the enzymes are found in the cytosol ; on the membrane
|what’s the typical composition of a phospholipid?|
|fatty acid tail + head group|
what’s the precursor to phospholipids?
where does the energy come from for the synthesis?
precursor – DHAP (dihydroxy acetone phosphate)
energy – from cytidine triphosphate
(instead of adenosine triphosphate, ATP)
what can be used to make phosphatidylcholine?
what is needed to convert it?
PL D enzyme ; SAM
|what’s the only antigenic phospholipid?|
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?
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
where is phospholipase C used?
what is the function of the products?
in second messenger pathway
it cuts IP2 into:
DAG -> (protein kinase C)
IP3 -> (Ca2+ release)
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?
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
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?
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
where are phosphatidylethanolamine ; phosphatidylcholine found mostly?
what category do they fall under?
what disease are these associated with?
ethanolamine – nerve tissue
choline – heart muscle
they are both plasmalogens
associated with Alzheimer’s disease
|what two compounds are the complex lipids synthesized from?|
what are gangliosides ?
where are some of them found?
what else do they determine?
complex sphingolipids with large polar head groups
6% in grey matter of brain
determine blood groups
what determines the different blood groups?
which enzyme determines A / B groups?
the sugar that’s attached to a ganglioside.
A – N-acetylgalactosamine transferase
B – Galactose transferase
muscle weakness / seizures
osteoperosis of long bones
what’s unique about this disease?
the only x-linked disease
kidney / heart failure
red-purple skin rashes
burning pain in lower extremeties
loss of myelin in white matter of brain
|how do you test for disorders of sphingolipid metabolism?|
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.