Complex Lipid Metabolism Flashcards
Lipid
insoluble in water
soluble in organic solvent
Phospholipid Structure
Hydrophilic head- P and glycerol backbone
Hydrophobic Tail- FA and hydrocarbon tail
Phospholipid Function
make membranes
reservoir for intracellular 2nd messengers
anchor point for membrane proteins
Phosphatidic Acid
PA
precursor for synthesis of all other glycerophospholipids and TAG
influence membrane curvature and vesicle formation
Phosphatidylcholine
PA + choline
most abundant phospholipid
stores choline
main part of lung surfactant
Lung Surfactant
decreases surface tension of extracellular fluid covering alveoli
reduces pressure needed to reinflate
prevents collapse
Phosphatidylethanolamine
PE
PA + ethanolamine
second most abundant
used for synthesis of PS
Phosphatidylserine
PS
PA + serine
in inner leaflet of plasma membrane
required for membrane synthesis
role in recognizing apoptotic cells
Phosphatidylinositol
PI
PA + inositol
stearic acid at C1 and arachidonic acid at C2
reservoir for arachidonic acid- precursor for prostaglandins
anchor points for proteins
Phosphatidylglycerol
PG
PA + glycerol
precursor of surfactant and the synthesis of cardiolipin
Cardiolipin
diphosphatidylglycerol
2 PA esterified thru phosphate groups
in inner mitochondrial membrane
maintains structure and function of ETC
Ether Glycerophospholipid
FA at C1 attached via ether linkage
Plasmalogens
Ether Glycerophospholipid
unsaturated FA at C1
Platelet Activating Factor
Ether Glycerophospholipid
saturated FA at C1 and short acetyl group at C2 (not acyl)
triggers thrombotic and inflammatory events
Phospholipases
PLP
hydrolyze phosphodiester bonds of glycerophospholipids
release bioactive molecules that act as 2nd messengers (DAG, IP3)
remodel phospholipids w/ Fatty acyl CoA transferase
Sphingomyelin
SM
ceramide + phosphocholine
main structural sphingolipid in PM
abundant in nerve tissue
Sphingosine
palmitic acid + serine
2nd messenger
precursor of sphingosine 1-P
Sphingosine -1-Phosphate
2nd messenger for 5+ GPCR
control endocytosis of rhodopsin and transient receptor potential channel
Glycosphingolipids in Human Cells
cellular interactions
growth and development
Antigenic- blood group, tumor, in embryonic dvlpmnt
cell surface receptors for cholera and tetanus
Neutral GSL
Cerebrosides
ceramide + sugar
component of membranes- mostly outer leaflet of PM
lipid raft formation
abundant in nerve tissue
Acidic GSL
Gangliosides
Ceramide + oligosaccharide + NANA
found in CNS Ganglia
Acidic GSL
Sulfatides
Galactocerebroside + SO3-
in brain and kidney
