Biochem Lec 3 - Lipid Metabolism - Complex lipid metabolism Flashcards
phospholipid characteristics
polar, ionic compounds
what is the predominat lipid of cell membranes
phospholipids
2 classes of phospholipids
glycerophospholipid (glycerol backbone)
spingophospholipid (choline / contain sphingosine)
what are phospholipids that contain glycerol called
Glycerophospholipids or phosphoglycerides
how are glycerophospholipids formed
from phosphatidic acid (PA) and an alcohol
alcohol group can be from serine, ethanolamine, choline
important of spingomylein
constituent of the myelin nerve fibers
where are most phospholipids syntehsized
smooth ER
after synthesis of phospholipids where do they go
transported to golgi apparatus then to membranes of organelles or the plasma membrane, or secreted from cell by exocytosis
what are the most abundant phospholipids in the eukayotic cell
phosphatidylethanolamine and phosphatidylcholine
(not serine)
how are phosphoglycerides degraded
through phospholipases (hydroylze and cleave the phosphodiester bond)
phospholipases release molecules that can serve as messengers such as
DAG (diacylglycerol) and IP3 (inositol triphosphate)
where are phospholipase A2 found
mammalian tissues and pancreatic juice, saneka nd bee venom
where are phospholipase A1 present
many mammalian tissues
where is phospholiase D found
priamrily in plant tissue
where is phospholipase C found
in liver lysosomes and a-tox of clostridia and other bacilli
what degrades spingomyelin
sphingomyelinase (removes phosphorylcholine, leaving a ceramide)
niemann-pick disease is a what deficiency
spingomyelinase deficieny
large liver and spleen filled w lipid
severe mental retardation
death in early childhood (type A)
what is the composition of glycolipids
contain both carb and lipid but no phosphate
phospholipid spingomyelin and glycolipids are derivatives of what
ceramides
where are glycolipids primarily found
nerve tissues
types of glycospingolipids
neutral - are cerebrosides , (contains molecule of galactose or glucose)
acidic - NANA, a sialic aci in gangliosides
where does synthesis of glycospingolipids occur
golgi apparatus
what enzyme for synthesis of glycospingolipid
glycosyl transferase
enzymes in the degradation of spingolipids
b-galatosidase
nana
neuraminidase
what are extremely potent compounds that elict physiologic imflammatory repsonse and pathologic hypersensitivty
prostaglandins/eicosanoids w 20carbons
what enzymes in prostaglandin synthesis
cox1 (constitutive), cox 2 (nonconstitutive)
what is the dietary precursor of prostaglandins and thromboxanes
linoeic acid
inhibitors of prostaglandin syntehsis
cortisol and asprin
what acid is important in syntehsis of prostaglandins and thromboxanes
arachidonic acid
what are leukotriene
mediator of allgeric response
leukotriene syntehsis is not affected by
NASAID (non sterodial anti inflammatory drugs)
NSAID inhibits what
Cox 1, cox 2
Which Phospholipase plays a role in producing secondary messengers (activated by PIP2)
Phospholipase C
which phosphopliase acts on phosphatidyl inositol, and releases arachidonic acid (the precursor of prostaglandins)
phospholipase A2
which phospholipase is inhibited by glucocorticoids (for example cortisol)
phospholipase A2
which phospholipase is activated by trypsin and requires bile salts for activity andi is involved w pancreatic secretions
phospholipase A2
gangliosides
glycosphingolipids composed of a ceramide lipid tail attached through glycosidic linkage to a glycan headgroup containing one or more sialic acid (NANA) residues
(an acidic glycospingolipid)
