Beta Oxidation Flashcards Preview

MCM Exam 1 > Beta Oxidation > Flashcards

Flashcards in Beta Oxidation Deck (14):
1

SCFAs and MCFAs enter the mitochondria by:

Diffusion

2

LCFAs and VLCFAs enter the mitochondria by:

AT

3

Enzymes of the carnitine shuttle (4)

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

4

Fatty Acyl CoA Synthetase function

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

5

CPT 1 function

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

6

CACT

Allow fatty acyl carnitine to enter the mito matrix.

7

CPT II

Remove carnitine and recreate fatty acid CoA

8

4 Steps of Beta Oxidation

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

9

Beta oxidation of odd number FAs (4 steps)

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

10

Beta oxidation of VLCFAs

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

11

MCAD Deficiency

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

12

3 Ketone bodies

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

13

Physiological ketosis

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

14

Pathological ketosis

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