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