Flashcards in Complex Lipids Deck (65):
What are the 3 main functions of Triacylglycerides?
Trihydric alcohol is related to what part of a TAG?
The esterfication of glycerol with fa what would be the product?
What does saponification mean?
Treatment with alkali
The saponification of triacylglycerols leads to the formation of?
hydrolysis and formation of fatty acid salts or soaps.
In TAG synthesis we want to produce glycerol phosphate. From what biochemical cycle is the glycerol phosphate come from?
Glycolysis via oxidation of DHAP or phosphorylation of glycerol by glycerol kinase.
The final destination of TAGs (2)
Liver: packaged into VLDLs
Adipocytes: packed into nearly anhydrous lipid droplets.
What are the membrane lipids?
Phospho and Glycolipids
Polar membrane lipids are known to have this special property?
Amphipathic - having polar group on one end and a hydrophobic group at the other.
How do we synthesize Phospholipids?
A phosphate esterfied to glycerol or sphingosine
Sugars esterfied to glycerol or sphingosine is known as?
Name the two classes of phospholipids
What are the non polar membrane lipids?
What makes up a Glycerophospholipid?
Sphingolipids are composed of?
Are glycerophospholipids: non polar, polar, highly polar
Name a glycerophospholipid
What is a second type of a glycerophopholipid group
Ether Lipids - ether linkage instead of an ester linkage.
What is considered one of the most potent bioactive molecules synthesized and released by a variety of cells?
Platelet Activating Factor PAF
What cells does PAF activate?
Sphingosine has what type of long chain backbone? Instead of?
Amino alcohol backbone instead of glycerol backbone
The fatty acid also has a different linkage in a sphingosine. What is the difference?
Amide linkage not ester
In what tissues do we find spingolipids?
Neural and non neural tissues.
When X = H for spinghosine what is the name of that sphingolipid?
Name another important Sphingolipid found in a lot of neural tissue
What type of acid is made during the synthesis of TAGs
Phosphatidic acid can make 2 different compounds. What are they?
CDP-diacyclglycerol to attach glycerol to inositol
CDP-alcohol -choline, or -ethanolamine
What can be made from choline and ethanolamine directly?
PC and PE
What is the name of the major surfactant in the lungs and what does it allow for?
DPPC or dipalmitoyl phophatidyl choline allows for ease of alveolar inflation and prevents its collapse
DPPC is secreted by what type of cells?
Type II Pneumocytes
What syndrome is related to surfactant production? Is it too much or too little surfactant secretion?
Respiratory Distress Syndrome RDS in perterm infants with insufficient surfactant production.
A fetus must get to how many months for adequate production of surfactant?
What can accelerate lung maturation in a fetus?
Giving the mother glucocorticoids shortly before delivery
What is another method to prevent and treat infant RDS?
Giving natural or synthetic surfactant by intratracheal infusion
Humans cannot synthesize enough of this amino acids to cover our needs and this is an essential nutrient of the body?
A Salvage Pathway involves either these two processes?
1. Decarboxylating phosphatidyl serine or
2. Exchanging serine in PS with Ethanolamine
Exchanging serine in PS with Ethanolamine is followed by these 3 chemical processes:
SAM mediated methylations
Why do we need Phosphatidyl Inositol?
It serves as a reservoir of arachidonic acid in membrane and provides the substrate for prostaglandin synthesis.
Phosphatidyl inositol is synthesized from what?
Free Inositol and CDP-diacylglycerol
What type of acid does phosphotidyl have on carbon 1 of its glycerol? carbon 2?
C1: Stearic Acid
C2: Arachidonic Acid
The phosophorylation of membrane-bound phosphatidylinositol produces this compound?
Phosphatidylinositol 4,5-bisphosphate (PIP2)
What enzyme can degrade PIP2?
Why does the degradation of PIP2 occur?
In response to a variety of neurotransmitters, hormones, and growth factors to receptors on the cell membrane
The product of the degradation of PIP2?
1,4,5- triphosphateinositol and diacylglycerol
1,4,5- triphosphateinositol and diacylglycerol mediate what important cell functions?
The activation of intracellular calcium and protein kinase C
How can some specific proteins attached to membrane bound glycosylated phophatidylinositol GPI?
Covalently attached via a carbohydrate bridge
Being attached to a membrane lipid allows GPI-anchored protein to do what?
Lateral mobility on the surface of the plasma membrane
How can the protein be cleaved off its anchor?
By the action of phospholipase C
What is the function of GPI?
Anchors proteins to the cell so it could travel the membrane interrogating the extracellular space.
For the disease Paroxsymal nocturnal hemoglobinuria (PNH) the most common enzyme that is defective is?
phosphatidylinositol glycan A
Where is the gene that codes for PIGA located?
What does a phospholipase recognize?
An intact phospholipid
Phospholipase A1 does what?
Hydrolyzes the C1 ester, releasing a fa
What is the function of Phospholipase A2?
Hydrolyzes the C2 ester
Where is Phopholipase A2 prevalent and what is it important for?
In tissues, pancreatic juice.
Important for release of arachidonic acid
What will inhibit Phopholipase A2?
Glucocorticoids ex: Cortisol
What is a major structural lipid found in membranes?
Sphingomyelin is initially synthesized using what two things?
Where is sphingomyleninase's found?
Sphingomyelininase initiates degradation by removing what group of the sphingomyelin? what does it leave behind?
Phophorylcholine leaving a ceramide
What breaks down a ceramide?
What makes up a Neutral Glycosphingolipid?
A glucose or galactose or other neutral carb + ceramide
What part of the Neutral Glycosphingolipid is the hydrophobic tail?
An oligosaccharide containing one to several acidic sugar derivatives attached to ceramide makes what?