TAG Degradation, Fatty Acid oxidation, and Ketone Body Metabolism

Question 1

Two key rate limiting enzymes of fatty acid oxidation

Answer 1

carnitine palmitoyl transferase-1

AcCoA carboxylase

Question 2

hormone sensitive triacyl glycerol lipase (HSTL/HSL)

Answer 2

catalyzes the formation of glycerol and fatty acids from TAGs. Thyroid and adrenocortico hormones are required for normal activity

activated by cAMP dependent PKA and epi, ACTH

inhibited by insulin and prostaglandins

Question 3

Perilipin

Answer 3

avtivated when P. Needed for HSTL to translocate to surface of fat droplet and hydrolyze TAG

Question 4

Fate of the products of TAG break down

Answer 4

Released fatty acids: enter into the circulation, bind to, albumin, are carried to muscle, liver, etc. used for beta oxidation and energy production

Released glycerols: transported to liver and kidney. glycerol kinase phosphorylated glycerol to glycerol-3-phosphate, which can be used in gluconeogenesis.

Question 5

glycogen vs TAG

Answer 5

can expand TAG storage in our bodies but glycogen storage is limited.

Question 6

Major ATP producing pathway of the body

Answer 6

mito beta oxidation of fatty acids

ATP is formed from the metabolism of NADH, FADH2, AcCoA.

Question 7

which tissues use fatty acids?

Answer 7

liver

kidney cortex

heart

skeletal muscle

Question 8

Tissues that cannot directly use fatty acids for energy

Answer 8

RBC

Brain

nervous system

adrenal medulla

lens

Question 9

how much ATP does the complete oxidation of palmitate yield?

Answer 9

106 ATP

Question 10

What are the products of each cycle of fatty acid degradation?

Answer 10

1 acetyl CoA

1 NADH

1 FADH2

Question 11

What happens if carnatine is inhibted?

Answer 11

carnatine transports long chain fatty acids into the mitochondrial matrix for beta oxidation.

fatty oxidation would be inhibited and production of ATP would be inhibited

Question 12

What can a deficiency in medium fatty acid CoA dehydrogenase cause?

Answer 12

SIDS

Question 13

Where are ketone bodies formed?

Answer 13

synthesized from acetly coA in the mitochondria of the liver

Question 14

What is the rate limiting enzyme in mitochondrial biosynthesis of ketones in the liver?

Answer 14

HMG-CoA synthase

it is found only in the liver

Question 15

The key enzyme in ketone body utilization is?

Answer 15

succinyl-CoA transferase enzyme which transfers CoA from succinyl CoA to acetoacetate

this enzyme is not found in the liver