FA Beta-Ox and FA Ox- Brar

Question 1

What is the only FA to be considered gluconeogenic? How is it produced and what does it eventually become?

Answer 1

Propionyl CoA (from beta-ox of odd chain FA's)
End product=Succinyl CoA-->TCA-->Malate-->glucose (via gluconeogenesis)

Question 2

For beta-ox of odd chain FAs, 3 additional enzymes are required to metabolize propionyl CoA. What cofactors are required (3)?

Answer 2

Biotin, ATP, and vitamin B12

Question 3

What are the 3 ketone bodies? Who uses them?

Answer 3

• Acetoacetate, acetone and 3-hydroxybutyrate

- skeletal muscle, brain, kidney, intestinal mucosa.

Question 4

What are the 6 ketogenic AAs? What can they be broken down into?

Answer 4

-Leucine, Isoleucine, Lysine, Tryptophan, Phenylalanine and Tyrosine.
(Please let tommy in the library)
-Can be broken down into AcCoA or acetoacetyl CoA

Question 5

What is peroxisomal Beta-Ox used for? How does it differ from mitochondrial Beta-Ox?

Answer 5

• Exclusive site of very long chain FA oxidation (24-26 carbon)
• the long chain FA acyl CoA synthetase in the peroxisomal membrane DOES NOT require carnitine to translocate acyl CoA derivatives across the membrane.

Question 6

Where does long chain branched FA (alpha-Ox) take place? What is produced? What are the common LCBFAs (2)?

Answer 6

• Oxidized in peroxisomes to a 8 carbon branched FA which is then degraded further in the mitochondria.
• Pytanic acid and pristanic acid (Breakdown products of chlorophyll, consumed through green vegetables, NOT found in animals)

Question 7

What is MCAD Deficiency? What alpha-ox pathway is upregulated?

Answer 7

• Medium Chain Acyl CoA DH

- Phytanic Acid

Question 8

What is omega-ox? Where does it take place? What cofactors are required?

Answer 8

• Fatty acids are oxidized at omega end by endoplasmic reticulum enzymes.
• Process utilizes cytochrome P450, molecular oxygen and NADPH to oxidize the omega carbon to an alcohol.

Question 9

How are peroxisomal alpha and beta oxidation and microsomal omega oxidation regulated?

Answer 9

Substrate availability only

NO FEEDBACK REGULATION