Lipids Flashcards
Phosphatidylcholine
Major component of cellular membranes - primarily on outer leaflet
Provides monolayer in lipoproteins
Secreted by the liver into the bile for cholesterol transport and also for dietary lipid digestion
Provides lung surfactant (dipalmitoyl-PC) in the alveoli of the lung
Used for synthesis of sphingomyelin
Phosphatidylinositol (PI)
Found on inner leaflet of cell membrane
Forms phosphatidylinositol-bisphosphate (PIP2) by the addition of 2 Posphates
Cleavage by phospholipase C generates the second messengers DAG and inositol-trisphosphate (IP3). IP3 binds to a receptor to open the calcium ion channel of the ER..
Cardiolipin
Di-phosphatidylglycerol
Phospholipid found mainly in the inner mitochondrial membrane.
Needed for respiratory complexes of the electron transport chain
Sphingomylin
major structural phospholipidin myelin of nerve fibers and in gray matter of the brain
Synthesis of sphingomyelin uses phosphatidylcholine
Palmitate
16:0
Stearate
18:0
Oleic Acid
18:1 omega 9
Linoleic Acid
18:2 omega 6
essential fatty acid
can form arachidonic acid
Alpha-linoleic Acid
18:3 omega 3
essential fatty acid
can form EPA and DHA
Arachidonic
20:4 omega 6
Eicosapentaenoic Acid (EPA)
20:5 omega 3
Docosahexaenoicacid (DHA)
20:6 omega 3
DHA in phospholipids of the brain provides a high fluid microenvironment.
DHA is important for brain functions and the visual cycle in the retina
Essential Fatty Acids
Components in biological membranes and modify the fluidity of the membrane either by themselves or by their longer family members
Can pass through the adult blood-brain barrier. Arachidonic acid, EPA and DHA are found in milk and can enter the developing brain in infants
Deficiencies are rare, can lead to scaly dermatitis, hair loss, and poor wound healing and visual and neurologic abnormalities
