Flashcards in Complex Lipid Metabolism Deck (64):
Free fatty acids are a major component of membranes. True or false?
false; minor component
Fatty acids are ___ ___ acids
Describe aliphatic carboxylic acids
generally long, unbranched, even number of carbon chains, length is usually 12 - 24, saturated FAs
Saturated fatty acids contain no C=C double bonds. True or false?
T C=C double bonds found in nature are what orientation
In regards to major complex lipids, Triacylgycerols (TAG) have 3 acyl groups in ___ linkage to a molecule of glycerol
In regards to TAG, the storage of fatty acids is primarily in ___ tissue but also found as lipid droplets in many cell types
Phosphoglycerides (phospholipid) have a glycerol backbone. Describe this backbone.
two fatty acid molecules attached in ester linkage and a phosphate on the third hydroxyl glycerol. The phosphate is usually esterfied to another alcohol
Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phospatidylinositol, and cardiolipin are all what?
Plasmalogens are an alkyl alcohol attached via an ___ linkage on position ___ of the glycerol
True or false? there may be plasmalogen forms of PC
Where are plasmalogens synthesized?
This is a phospholipid that does not contain glycerol
Sphingomyelin is synthesized from what?
amino alcohol spingosine
Glycosphingolipids (not phospholipids) are composed of what?
sphingosine, a fatty acid, and one or more carbohydrate or carbohydrate derived structure
note: a sphingosine plus a fatty acid is called a ceramide
Galactosyl ceramide is an example of what?
Addition of more carbohydrates and sialic acid to produces more complex glycosphingolipids known as ____
Synthesis of both TAG and phoshoglycerolipids require what?
In regards to TAG synthesis, what two sources is glycerol-3-phosphate derived from?
1.dihydroxyacetone phosphate (glycolytic intermediate)
2. the liver and intestine can obtain it directly from glycerol
In regards to TAG synthesis, the enzyme glycerol kinase is expressed primarily in ___ and ___
____ acid is a common intermediate in the synthesis of TAG and phospholipid
TAG synthesis occurs in most tissue, but is most active in ___, ____, and ____
liver; adipose; intestine
True or false? In regards to TAG synthesis, all tissues can utilize the phosphatidic acid pathway
In the phosphatidic acid pathway, what happens to phosphatidic acid
it is dephosphorylated and a third acyl group is added
In regards to TAG synthesis, this pathway occurs only in the intestinal mucosa
In regards to TAG synthesis - specifically, the monoacylglycerol pathway, MAGs are absorbed from where?
from digestive products in the gut
TAG produced in the ___ may include fatty acyls from the diet, or produced from excess carbohydrate and protein
TAG produced in the liver will be packed for secretion as ____
True or false? Most of fatty acid synthesis occurs in adipose tissue
false; very little
The TAGs produced in adipose will be stored as __ ___
Fatty acids in the intestinal mucosa are from where?
TAGs in the intestinal mucosa are packaged as ____ for distribution
Muscle cells obtain their fatty acids from the TAG circulating from ___ and from ___
TAGs are stored as __ ___ in muscle cells
In regards to phospholipid synthesis, all tissues except mature ___ ___ cells synthesize phospholipids
In regards to phospholipid synthesis, specifically synthesis of phosphatidylcholine, choline is activated by ______ followed by addition of ___ from ___
phosphorylation; CMP; CTP
In regards to phospholipid synthesis, specifically synthesis of phosphatidylethanolamine, the CDP-choline is added to what?
In regards to phospholipid synthesis, phsophatidylserine is produced primarily by exchanging ___ for the ___ of PE
In regards to phospholipid synthesis, specifically the synthesis of phosphotidylinositol and cardiolipin, phosphatidic acid has to be "activated" by formation of ___-___
In regards to phospholipid synthesis, specifically Dipalmitoylphosphatidylcholine, is secreted by certain types of ___ cells as the major lipid component of ___ ___
lung; lung surfactant
Dipalmitoylphosphatidylcholine is found in the extracellular fluid lining the ____
Dipalmitoylphosphatidylcholine is composed of ___% lipids, and ____% proteins
Surfactant decrease the surface tension, reducing the pressure needed to do what?
reinstall the alveoli
Reduced ability to synthesize and/or secrete surfactant is associated with what?
respiratory distress in premature infants
This is a special glycerol ether phospholipid formed by blood cells
Platelet activating factor
In regards to phospholipid synthesis, specifically platelet activating factor, induces platelet aggregation at ___ concentrations
In regards to phospholipid synthesis, Sphingomyelin is formed from what two things?
palmitoyl-CoA and Serine
Sphingosine + fatty acyl in amide linkage = ?
In regards to glycosphingolipids, a ceramide + one carbohydrate residues is called what?
ex: galctoceramide, glucosylceramide
In regards to glycosphingolipids, a ceamide + 2 or more carbohydrates is called what?
In regards to glycosphingolipids, gangliosides contain a globoside and one or more molecules of a ___ acid
Phospholipase A2 is secreted by the ___ as a digestive enzyme
note: also found in snake venom; Phospholipase C and D are signaling components
In regards to turnover of gangliosides, these are specific lysosomal enzymes involved in the catabolism of sphingolipids
Genetic deficiency of any sphingolipidoses causes what?
sphingolipidosis (accumulation of specific lipid)
Tay-Sachs disease is caused by a deficiency in what?
note: causes accumulation of Gm2
In regards to turnover of gangliosides, What are the symptoms of Tay-Sachs disease?
rapid, progressive and fatal neurodegeneration; blindness; cherry-red macula; muscular weakness; seizures
In regards to turnover of ganliosides, Gaucher is found in 1/1000 Ashkenazi Jewish Persons. It is caused by a deficiency in what?
note: causes accumulation of glucocerbroside
What are the symptoms of Gaucher?
hepatosplenomegaly, osteoporosis of long bones, severe neurological signs
Phosphatidylethanolamine is a ____
Phospholipase A1 hydrolyzes what bond in a phospholipid?
O - C - R1
Phospholipase A2 hydrolyzes what bond in a phospholipid?
R2 - C - O
Phospholipase B hydrolyzes what bond in a phospholipid?
same as both A1 and A2
Phospholipase C hydrolyzes what bond in a phospholipid?
O - P - O - N base