Fatty Acid Metabolism Flashcards
What are chylomicrons?
lipoproteins that consist of fats that transport fat via the lymphatic system and bloodstream to organs
How are triglycerides broken down into free fatty acids?
hydrolysis reaction
What type of reaction do free fatty acids undergo to break down for energy?
beta-oxidation
Where does beta-oxidation occur?
mitochondrial matrix
What has to occur to free fatty acids in order to be transported into the mitochondrion for beta-oxidation?
must be activated by acyl-CoA synthetase which requires the investment of 2 ATP
What is a basic summary of beta-oxidation?
cleaving of a two-carbon acetyl-CoA from the fatty acid to produce 1 NADH and 1 FADH2
process repeats until entire chain is cleaved
How is beta-oxidation of unsaturated fatty acids different?
when cleavage reaches the double bond must bring in an isomerase to rearrange the bond for further cleave
**if multiple double bonds then it requires an isomerase and reductase
What is ketogenesis?
liver generates ketone bodies in the mitochondrial matrix during periods of starvation when all glycogen stores have been exhausted
What are the ketone bodies?
acetone, acetoacetate, and beta-hydroxybutyrate
What are the ketone bodies generated from?
acetyl-CoA
What is the purpose of ketone bodies?
they can pass the blood brain barrier, turn back into acteyl-CoA and enter the Krebs Cycle providing energy to the brain
What is catabolism?
the breakdown of a substance
What is anabolism?
the synthesis of a substance
Where does fatty acid synthesis take place?
cytoplasm
What is a basic description of fatty acid synthesis?
repeated addition of two-carbon subunits to a the desired chain length (16-carbon)
What is the first step in fatty acid synethesis?
activation of acetyl-CoA in a carboxylation reaction facilitated by acetyl-CoA carboxylase forming malonyl-CoA
What is the committed step of fatty acid synthesis and what does it require?
activation of acetyl-CoA to form malonyl-CoA
requires investment of ATP
What enzyme is responsible for the addition of two-carbon subunits during fatty acid synthesis?
fatty acid synthase
What is the ACP?
acyl carrier protein
What are the two main domains on fatty acid synthase?
ACP and cysteine residue domain
What is required for reducing the newly formed X-carbon unit on fatty acid synthase?
NADPH from the pentose phosphate pathway
Which domain does the new malonyl-CoA bind to on fatty acid synthase?
ACP
What are modification that can be made to the 16-carbon chain made from fatty acid synthase?
elongation and addition of functional groups
