Ch. 28B, 29 Fatty Acid and Lipid Synthesis
The ER performs what 2 key functions in fatty acid synthesis?
Elongation past Carbon-16 palmitate AND introduces double bonds into saturated fatty acids
What are the 3 stages of Cholesterol?
1) Mevalonate to Isopentyl Pyrophosphate 2) 6 molecules of Isopentyl Pyrophosphate to Squalene 3) Squalene is cyclized and becomes Cholesterol
Fatty acid synthase is multifunctional enzyme where all the components are located on a _____ polypeptide chain but exits a ______ dimer
single, homo
The reaction of Acetyl-ACP (2 C's) with Malonyl-ACP (3 C's) produces a _____ carbon compound called Acetoacetyl-ACP
4 carbons, due to decarboxylation reaction
Fatty acid synthesis requires what for molecules?
Acetyl-CoA ATP CO2 NADPH
Phosphatidate is converted to _____, as the activate precursor to the synthesis of Cardiolipin and Phosphotidylinsitol 4,5-biphosphate
CDP-diacylglycerol
How does formation of Ketone bodies contribute to cholesterol synthesis?
Fatty acids are broken-down into ketone bodies and then converted to Acetoacetyl-CoA which then reacts with Acetyl-CoA to form the precursor of Cholesterol, HMC-CoA
What separates Low Density Lipids from High Density Lipids?
Low have higher lipid/protein ratio than High
The 2nd round of fatty acid synthesis involves the condensation reaction of _____ and _____?
Malonyl-ACP and Butyryl-ACP
What is the key regulatory enzyme in lipid synthesis?
Phosphatidic acid phosphatase
If an alcohol is the activate site precursor and not diaglycerol, the phospholipids ______ and ______ are synthesized
PhosphatidylETHANOALAMINE and PhosphatidylCHOLINE
Low Density Lipids are delivered into the cellular cytoplasm by what?
Receptor mediated endocytosis
One regulation method is "Transcriptional Regulation" Describe what happens when cholesterol levels are LOW?
SCAP protein attached to SREBP proteins move to the golgi complex where SREBP is cleaved twice to cleave off SRE. Then, SRE moves to nucleus and binds to DNA resulting in increase of enzymes on cholesterol production
Ceramide has _____ as its backbone structure instead of glycerol
Sphingosine
What Vitamin base from cholesterol uses sunlight for its synthesis?
Vitamin D
What does a transferase do?
moves a functional group BETWEEN DIFFERENT molecules
What does a mutase do?
moves a functional group WITHIN a molecule