Beta Oxidation

Question 1

SCFAs and MCFAs enter the mitochondria by:

Answer 1

Diffusion

Question 2

LCFAs and VLCFAs enter the mitochondria by:

Answer 2

AT

Question 3

Enzymes of the carnitine shuttle (4)

Answer 3

1. Fatty Acyl CoA Synthetase (FACOAS)
2. CPT 1 (RLS)
3. CACT
4. CPT II

Question 4

Fatty Acyl CoA Synthetase function

Answer 4

FA –> Fatty acyl CoA (moves inside the IMS)

Question 5

CPT 1 function

Answer 5

AKA carnitine palmitoyltransferase I and carnitine acyltransferase.
Function is to add carnitine to fatty acyl CoA.

Question 6

CACT

Answer 6

Allow fatty acyl carnitine to enter the mito matrix.

Question 7

CPT II

Answer 7

Remove carnitine and recreate fatty acid CoA

Question 8

4 Steps of Beta Oxidation

Answer 8

Ox (ACAD), H (ECAD), O (3-HCAD), T (ACAAT or ketothiolase)

Question 9

Beta oxidation of odd number FAs (4 steps)

Answer 9

1. Metabolize duntil propionayl-CoA remains (3 carbons)
2. Propionyl CoA carboxylase uses ATP to become methylmalonyl-CoA
3. Methylmalonyl mutase generate succinyl CoA
4. Succinyl CoA enters TCA

Question 10

Beta oxidation of VLCFAs

Answer 10

Occurs in peroxisome and does not produce ATP.
Produced H2O2, but turned into O2 and H20.
First step is catalyzed by acyl CoA oxidase.

Question 11

MCAD Deficiency

Answer 11

Impairs breakdown of MCFAs.
Leads to secondary carnitine deficiency, so FAs accumulate in liver.
Patients must depend on Glc as source of energy.

Question 12

3 Ketone bodies

Answer 12

1. Acetoacetate
2. b-hydroxybutyrate
3. Acetone
   Produced in liver only.

Question 13

Physiological ketosis

Answer 13

Mild to moderate increase of ketones bodies. Occurs in mild fasting, during pregnancy and in babies.

Question 14

Pathological ketosis

Answer 14

Occurs when glucagon/insulin ratio is high, favoring FA breakdown.