lipids & surfactants Flashcards
what do phospholipases (PL) do
cleave phospholipids
4 types of phospholipases
PLA1
PLA2
PLC
PLD
where does PLA1 cleave phospholipid
at fatty acyl chain
where does PLA2 cleave phospholipid
at fatty acyl chain (& releases arachidonic acid)
where does PLC cleave phospholipid
at head group (& releases phoshate)
where does PLD cleave phospholipid
at head group (does not take phosphate)
prostaglandin production pathway w regulation
reaction that produces DAG, IP3
PIP2
–(phospholipase C)–>
DAG + IP3
how does IP3 perform intracellular signaling
IP3 binds to ER, which releases sequestered Ca2+
how does DAG perform intracellular signaling
DAG + Ca2+ activate protein kinase C
->
PKC phosphorylates appropriate cellular proteins
what is cardiolipin, what is it’s structure, & why is it important
a type of phospholipid
2 phosphatidylglycerols stuck together
critical for mitochondria
majority of acyl chain of cardiolipin contains _____
linoleic acid
Barth syndrome
-inheritance
-mutation
-symptoms
rare X-linked disease
mutation of TAZ1 enzyme, that adds linoleic acid to cardolipin
cardiac / skeletal myopathies; death via heart failure
what is plasmalogen, what is unique about it’s structure, & where is it located
a phospholipid
contains ether linkage (instead of ester)
in nerve tissue
what is PAF (platelet-activating factor), & what is it’s function
a type of plasmalogen
promotes oxidative burst of leukocytes as part of host defense
Niemann-Pick disease type A
-severity
-symptoms
-mutation
severe, <1% enzyme activity
death in early childhood, severe intellectual disability
SMPD1 gene; sphingomyelinase deficiency,
sphingomyelin accumulates in lysosomes (lysosomal storage disease)
Niemann-Pick disease type B
-severity
-symptoms
-mutation
less severe
life expectancy into adulthood, hepatomegaly
SMPD1 gene = sphingomyelinase deficiency = sphingomyelin accumulates in lysosomes (lysosomal storage disease)
Niemann-Pick disease type C
-symptoms
-mutation
neuro. sxs, hepatomegaly, jaundice
NPC1 or NPC2 genes = lysosomal cholesterol accumulation
surfactant composition
lipids, proteins, carbs
(main lipid = DPPC)
how to assess lung maturity of newborn
L/S ratio
(DPPC / sphingomyelin)
L/S ratio > 2 = lung maturity
what fetus age does DPPC begin replacing sphingomyelin
32 weeks
why do alveoli need surfactant
bc they don’t have cilia / microvilli
surfactant proteins (SP) that are hydrophilic glycoproteins
SP-A
SP-D
surfactant proteins (SP) that are hydrophobic glycoproteins
SP-B
SP-C
function of SP-A, SP-D
regulate immune / inflammatory response
function of SP-B, SP-C
monolayer spreading & recruits lipids to surface films
surfactant metabolism dysfunction genetic disorder
-mutations
-symptoms
SP-B, SP-C, ABCA3
respiratory distress, newborn may need lung transplant
