Lipid Metabolism Flashcards
What is hydrophobic channeling?
Surmounts the kinetic barrier of lipid solvation
What is a lipase?
Go through lipase mechanisms
Check textbook for answer
What is an intestinal fatty acid binding protein?
-They increase the effective solubility of water-insoluble fatty acid
-How we are able to transport the fatty acids
Where does Beta-Oxidation take place?
In the mitochondria
What are the four steps of Beta-Oxidation
1) Take the fatty acyl-CoA and do a dehydrogenation reaction therefore you have an acyl-CoA dehydrogenase and make an alpha-beta unsaturated system that’s conjugated to the carbonyl of the thioester
2)enoyl-CoA hydratase (EH) adds water in a Michael addition fashion to the beta-carbon. Now you have an alcohol at the beta position.
3) Beta oxidation with dehydrogenase enzyme to make a beta keto coenzyme a thioester
4) Uses enzyme thiolase. Thiolase cleaves the beta-keto ester to form acetyl-CoA (can be used in the TCA cycle) AND fatty acid acyl-CoA with another beta carbon that can re-enter the cycle.
How can you predict how much energy you can get out of a fatty acid?
-Count beta carbons
-EX you counted 7 beta carbons therefore there are 7 rounds of beta-oxidation
-yields 7 FADH2 (step 1 and you get 1.5 ATP per 1 FADH2)= 10.5 ATP, 7 NADH (step 3 you get 2.5 ATP per 1 NADH)= 17.5 ATP, 8 AcCoA (goes to the TCA cycle therefore 8 FADH, 24 NADH), resulting in net 106 ATP THAT’S A LOT
What does Enoyl-CoA isomerases do?
Able to move double bonds of the unsaturated fatty acids to create the correct stereochemistry for beta-oxidation
What is Succinyl-CoA converted to to achieve net oxidation via the TCA cycle?
Succinyl-CoA is converted to Malate which is then converted to pyruvate
What are peroxisomes
-selective for very long chain fatty acids
-differs only in first step, which used FAD/O2 directly to oxidize FA-CoA to transdelta2-enoyl-CoA
What is Phytanic Acid Oxidation
-lots of specializes FAs
require specializes degradation pathways
-phytanic acid is derived from chlorophyll’s phytyl side chain
-requires alpha-oxidation to breakdown
What makes biosynthesis irreversible?
Acetyl-CoA carboxylase (ACC) converts acetyl-CoA to Malonyl-CoA
What is acetyl-CoA carboxylase?
-Multi-enzyme complex
-biotin carboxylase (BC) domain
-Carboxyltransferase (CT) domain
-Biotin carboxyl-carrier protein (BCCP)
-cannot continue with synthesis without the use of Acetly-CoA carboxylase.
Write the Fatty Acid Biosynthesis Pathway
Look at notes for answer
Where does biosynthesis take place?
takes place in the cytoplasm
