FA Oxidation Flashcards
Fatty Acyl CoA Synthetase: Function and Location
Activates LCFA(Long Chain Fatty Acids) by using ATP to form a thiester bond with CoA: forms FA-CoA.
Location on the cytoplasmic side of the outer mitochondrial membrane.
CPT-I(Carnitine Acyltranferase): Function and Location
What inhibits it?
RATE Limiting Enzyme in FA Degradation. Transfers Fatty Acyl from FA-CoA to Carnitine: Forms FA-Carnitine.
Located in inter membrane space of Mitochondria.
Inhibited by Malonyl.
CACT (Carnitine-Acylcarnitine translocate): Function
Moves FA-Carnitine into the inter membrane space. Antiporter.
CPT-II: Function and location
located in the inner membrane. Transfers FA to CoA inside the inner membrane: FA-CoA.
ACAD (Acyl CoA Dehydrogenase): Function
Oxidizes the beta Carbon of FA-CoA to produce FADH2 and trans-enoyl-CoA. First step in the Beta Oxidation. Takes place in the Mitochondria.
How and where are VLCFAs converted into LCFAs?
They are oxidized in Peroxisomes.
What is the purpose of Beta Oxidation? What does it generate?
Acetyl CoA (enters TCA Cycle)
FADH2
NADH
What are the 4 steps of Beta Oxidation?
Oxidation
Hydration
Oxidation
Thiolysis
How are odd numbered FA handled in Beta Oxidation
Metabolized until Propionyl CoA. Then Propionyl CoA Carboxylase converts it to Methylmalonyl CoA. Methylmalonyl CoA Mutase further converts it to Succinyl-CoA. Enters TCA Cycle.
What enzymes are used in unsaturated FA during Beta Oxidation?
Reductase reduces double bonds.
Isomerase moves the disruptive bond.
How many ATPs does beta oxidation procure in peroxisomes?
NONE!
Produces H2O2 which is converted into water and oxygen by Catalase.
What are the 3 Ketone bodies (water soluble and acidic compounds)?
Acetoacetate
Beta-hydroxybutyrate
Acetone
In which organ(s) are Ketones produced?
Only in the Liver
What are the main substrates(in order) in the formation of Ketone Bodies? (enzymes are not important)
Acetyl CoA+Acetyl CoA=Acetoacetyl CoA
Acetoacetyl Coa—-HMG CoA—–Acetoacetate
Acetoacetate is the precursor of - Acetone and Beta Hydroxybutyrate.
What is Physiological Ketosis?
What causes Pathological Ketoacidosis?
- mild to moderate increase in ketone bodies.
- caused by an increase in the Glucagon/Insulin ratio favoring FA breakdown. Acetoacetate and Beta-hydroxybutyrate are strong acids, bringing the pH down and causing Acidosis.
