Beta Oxidation Flashcards
What is Beta Oxidation?
Breakdown of FA’s into Acetyl CoA to be used for Ketones or other metabolic fuel
What are the 4 stages of Beta Oxidation?
1.) Dehydration
2.) Hydration
3.) Dehydration
4.) Clevage
What is the catalyst step of Beta Oxidation?
FA is converted into FA Acel CoA (c)
What is the enzyme that converts FA into FA Acel CoA?
Fatty Acel CoA Synthetase
Where does the catalyst step of Beta Oxidation occur?
Cytoplasm
In order for the FA Acel CoA to diffuse into the mitochondrial membrane what must be added to it?
Carnitine
What two enzymes are used in the Carnitine Transport?
CAT1 (c) & CAT2 (m)
Why does a CoA Molecule need to be added to the FA Acel?
So it cannot leave the mitochondria
What is step 1 of Beta Oxidation (Dehydration)?
FA Acel CoA is converted into Enoyl CoA
What is the enzyme that converts FA Acel CoA into Enoyl CoA?
Acel CoA Dehydrogenase *(rate-limiting)
What are the byproducts of step 2 of Beta Oxidation?
FAD > FADH2
What is step 2 of Beta Oxidation (Hydration)?
Enoyl CoA is converted into BetaHydroxyAcel CoA
What is the enzyme that converts Enoyl CoA into BetaHydroxyAcel CoA?
Enoyl CoA Hydratase
What is a input of step 2 of Beta Oxidation?
H20 (hydration step)
What is Step 3 of Beta Oxidation (Dehydration)
BetaHydroxyAcel CoA is converted into BetaKetoAcel CoA
What is the enzyme that converts BetaHydroxyAcel CoA into BetaKetoAcel CoA?
BetaHydroxyAcel CoA Dehydrogenase
What are the byproducts of step 3 of beta oxidation?
NAD > NADH
What is the 4th step of Beta Oxidation (Clevage)?
BetaKetoAcel Coa is converted into Acetyl CoA
What is the enzyme that converts BetaKetoAcel CoA into Acetyl CoA?
Thiolase *(rate-limiting)
After Acetyl CoA is yielded from Beta Oxidation, where does it go?
Either into KREBS to spin the TCA cycle or used for Ketone Body Synthesis
If CHO are high in the blood stream what will that do to Beta Oxidation?
Down-Regulate / Increase Glycolytic Flux
What additional substrate is needed to utilize with Acetyl CoA to spin the TCA cycle?
Oxaloacetate
What is the primary rate-limiting enzyme of Beta Oxidation?
Acel CoA Dehydrogenase
What is the secondary rate-limiting enzyme of Beta Oxidation?
Thiolase
If Acetyl CoA & NADH are high what will happen?
Deactivates Pyruvate Dehydrogenase
= no enzymes for dehydration steps.
What enzymes are primarily responsible for Beta Oxidation taking place?
Acel CoA Dehydrogenase
BHAD (beta hydroxy acel dehyd)
Thiolase
Beta Oxidation potential is allosterically (feed-forward) regulated by?
NAD
FAD
Exercise
Diet
High amounts of Acetyl CoA have what regulation effect on Thiolase?
Negative Feedback > Puts the breaks on the clevage step
Exercise has what regulation cascade on Beta Oxidation?
Exercise >
Contraction >
ATP >
ADP >
AMP >
=
High AMPK > activates MCA
What transport protein is highly sensitive to MCA presence?
CPT-1
What is CPT-1 needed for?
Transport of long chain fatty acids
Too much citrate as a byproduct of the TCA cycle will do what to Beta Oxidation?
It will reverse the TCA cycle: (Citrate Lyase) will convert Citrate to Acetyl CoA, which high concentrations will deactivate PDH
