lipid metabolism 4 Flashcards
the cell membrane is a fluid mosaic of
lipids and proteins
the protein serve as
transporters
enzymes
receptors
mediators
what is function of mediators
that allows extracellular compounds such as hormones to exert intracellular effects
which are the major membrane lipids
phosphoglycerides
sphingolipids and cholesterol also present
name the lipid that forms the lipid bilayer
phospholipids
explain lipid bilayer structure
hydrophilic head groups interacting with water on both the extracellular and intracellular surfaces, and their hydrophobic fatty acyl chains in the central portion of the membrane
name the protein that embedded at the periphery
peripheral protein
integral protein located at
span from one side to other
on which side carbohydrates are attached to protein
exterior side of CM they extend into the extracellular space
what are the function of membrane
barrier
all functions of proteins
phospholipids are syntesized from
phosphatidic acid
name the two mechanism that add head groups to phosphatidic acid
head grp activation : phosphatidylcholine and phosphatidylethanolamine are produced
phosphatidyl serine is formed by a head group substitution of serine for ethanolamine in phosphatidylethanolamine
phosphatidylinositol, phosphatidylglycerol ,and cardiolipin are formed by
activating phosphatidic acid to CDP-DAG (cytidine diphosphate-diacylglycerol
phospholipids and sphingolipids are the major components of
cell membrane
what are amphipathic molecule
one portion is hydrophilic and associates with H2O and another portion contains the hydrocarbon chain derived from FAs which are hydrophobic associated with lipids
phosphoglycerides contain
glycerol, fatty acids and phosphate
phospholipase help in degradation of
phosphoglycerides
sphingolipids are synthesized from
ceramide, produced from serine and palmitoyl-CoA
during degradation lysosomal enzyme removes
phosphocholine and sugar units
which FA serve as a major component of lung surfactant in adults, allowing lungs to function properly
dipalmitoylphosphatidylcholine
dipalmitoylphosphatidylcholine develops in fetus
after week 30 of gestation
acute respiratory distress syndrome occur in premature infants due to
do not have an adequate amt of dipalmitoylphosphatidylcholine
name the disease that has deficient with following substance
alpha-galactosidase
beta glucosidase
sphingomyelinase
hexosaminidase
alpha-galactosidase - fabry’s disease
beta glucosidase - gaucher’s disease
sphingomyelinase-neimann pick
hexosaminidase - tay-sachs disease
peroxisomal disorders includes
adrenoleukodystrophy and zellweger syndrome
what is adrenoleukodystrophy
x-linked disorder
affects the transport of VLCFA into peroxisomes for initial oxidation
adrenoleukodystrophy leads to
accumulation of VLCFAs which appear to target the adrenal glands and myelin sheath for destruction
children with adrenoleukodystrophy experience
cognitive deficiencies, nervous system deterioration, seizures, visual impairment and may develop addison’s disease, a loss of adrenal gland function
lack of peroxisomes leads to
build up of VLCFAs, an inability to degrade branched FA
lack of peroxisome give rise to
zellweger syndrome
neonatal adrenoleukodystrophy
infantile refsum disease
give an eg of branched chain FA
phytanic acid
zellweger syndrome is a peroxisome biogenesis disorder, which is one of the
luekodystrophies
symptoms of zellweger syndrome
enlarged liver, mental retardation, and seizures
infants with zellweger syndrome lack
appropriate muscle strength and may be unable to move
the eicosanoids are synthesised from
PUFA
give eg for eicosanoids
prostaglandins, thromboxanes and leukotrienes
PUFAs are released from membrane lipid by___________ which is inhibited by ___________ and ______________
phospholipase A2
glucocorticoids and other steroidal anti-inflammatory agents
for prostaglandin synthesis, the PUFA is cyclized and oxidized by a ____________ which is inhibited by _______
cyclooxygenase
aspirin and the nonsteroidal anti-inflammatory agent
which eicosanoids are produced from arachidonic acid by a different pathway
leukotrienese
prostaglandins has effects on tissues includes
inflammation, pain, fever and aspects of reproduction
prostaglandins are known as
autocoids
These prostaglandins are known as autocoids because
they exert their effects primarily in the tissue in which they are produced
which prostacyclins inhibit platelet aggregation
PGI2 produced by vascular endothelial cells
what will promote platelet aggregation
thromboxanes (TXA2)
nonsteroidal anti inflammatory drugs (NSAIDs) are
aspirin and ibuprofen
NSAIDs inhibits
cyclooxygenase involved in prostaglandin synthesis
what are the action of NSAIDs
reduce pain, inflammation, and fever associated with the action of the prostaglandins
platelet aggregation in conjunction with
atherosclerotic plaques, often precipitates heart attacks
what are two form of cyclooxygenase
COX1 & COX2
name the drugs that affect COX1 & COX2
aspirin NSAIDs
name the specific drug that is reversible inhibitor that only affect COX2
celecoxib
which FA is the major precursor for the synthesis of the leukotrienes
arachidonic acid
arachidonic acid derived from
membrane phospholipids
what is the first step in synthesis of leukotrienes
oxygen is added by lipoxygenases and a family of linear molecule
what is formed in the synthesis of the leukotrienes
hydroperoxyeicosatetraenoic acids
( HPETEs)
leukotrienes are involved in which type of reaction
allergic reaction
leukotrienes contribute to the symptoms of asthma by
acting as bronchoconstricting agent, narrowing the airway, and making it more difficulty to breathe
solubility of ethanol
both lipid and water soluble
greater than 80% of the absorbed ethanol is metabolized in the
liver
what are the alcohol induced liver disease
fatty liver, alcohol-induced hepatitis, and cirrhosis
fatty liver result from ethanol inhibition of fatty acid oxidation, resulting in
fatty acid buildup in the liver
alcohol-induced hepatitis results from
acetaldehyde and free radical generation from ethanol metabolism in liver
cirrhosis occur as a
accumulation of damage to the hepatocytes, leading to fibrosis and loss of liver function
