Fat as Fuel

Question 1

What are trans fatty acids?

Answer 1

fatty acids are geometric isomers which are identical except for the double bond

Question 2

Why are triglycerides useful as energy?

Answer 2

They have compact storage, large body stores and good weight efficiency

Question 3

Uses of Glycerol?

Answer 3

Glycerol is water soluble and taken up by all tissues
It enters the glycolysis pathway for conversion to pyruvate, then into TCA cycle for oxidation to CO2
In the liver it enters glycolysis pathway and is converted to glucose by gluconeogenesis

Question 4

What happens in the beta-oxidation pathway?

Answer 4

Long chain fatty acids + CoAsh and thiokinase enzyme produce fatty acyl CoA

Question 5

The mitochondrial carnitine system using beta oxidation pathway products?

Answer 5

Fatty acyl CoA -> Enoyl - CoA
Enoyl - CoA + H2O -> 3-L-Hydroxyacyl-CoA
3-L-Hydroxyacyl-CoA -> B-ketoacyl CoA
B-ketoacyl CoA + CoAsh -> fatty acyl CoA + Acetyl CoA

Question 6

What happens to fatty acids the re-enter the carinitine system?

Answer 6

Shorter fatty acids reenter the reaction and proceed until 2 carbon units remain
Odd chain fatty acids generate acetyl CoA and Propionyl CoA to make an even number

Question 7

What happens without carnitine?

Answer 7

Long chain fatty acids do not enter the mitochondria

Question 8

What is the ATP yield from complete oxidation of acetyl CoA by TCA cycle?

Answer 8

80