complex lipids Flashcards
lipids
diverse and ubiquitous group of organic compounds that are insoluble in water but soluble in organic solvents
lipid classification
lipids
- glycerol based (glycerol backbone)
- none glycerol based (waxes, steroids, sphingolipids, glycosphingolipids
glycerol based lipids classification
- simple (fats and oils, glycerol + 3 FA)
- compound/complex (phospholipids, glycolipids)
glycerol with a simple sugar attached
glycoprotein
glycerophospholipids
hydrophobic tail, glycerol backbone, polar head
2 FA attached
sphingophospholipids
- shingomyelin
- polar head group
- backbone is amino alcohol
What is the only lipid that is also sphingophospholipid
sphingomyelin
what is the back bone made of in sphingophospholipids?
amino acids
hydrophilic head of phospholipids
phosphate group and glycerol backbone
hydrophobic tails of phospholipids
fatty acid hydrocarbon tails
phospholipid structure
amphipathic
arrangement of phospholipids
different depending on
- type of phospholipid
- types of FA
- level of saturation
phospholipid arrangement in water
hydrophilic heads out and hydrophilic tails in
- arrange in this way to form the lipid bilayer
- spontaneous
phospholipid functions
-serve as major structural component of all biological molecules and as part of the membranes and other compounds
Where are the hydrophobic heads of the phospholipid arranged at?
inner and outer surface of the bilayer
where are the hydrophobic tails of phospholipids arranged at?
associates with the non polar portions of other membrane constituents (glycolipids, proteins and cholesterol)
as part of the membrane, phospholipids function as…
- reservoir for intracellular second messengers
- anchor point for membrane proteins
what are some intracellular second messengers associated with phospholipids?
- PIP2
- IP3
- DAG
- ceramide
- sphingosine
- sphingosine 1-phosphate
phospholipids serve as components for…
- lipoprotein particles (chylomicrons, VLDL, LDL, HDL)
- pulmonary surfactants
- bile
phospholipids and dry eye
> 60nm thick tear film
phospholipids and cataracts
lower PL in lens with cataracts
glycerophospholipids in humans
- phosphatidic acid (PA)
- phosphatidylcholine (PC, lecithin)
- phosphatidylethanolamine (PE, cephalin)
- phosphatidylserine (PS)
- phosphatidylinositols (Pls)
- phosphatidylglycerol (PG)
- cardiolipin (diphosphatidylglycerol)
- ether glycerophospholipids
phosphatidic acid (PA)
- simplest of all PL
- a precursor for he synthesis of all other glycerophospholipids and TAG
- signaling molecule
- influence membrane curvature and vesicle formation
phosphatidylcholine (PC, lecithin)
- first found in egg
- PC=PA + choline
- MOST ABUNDANT
- storage for choline
- lung surfactant (DPPC)