FA metabolism Flashcards
Long chain FA are activated in the cytosol by how many ATP?
2 ATPs
Where does FA oxidation occur?
Mitochondrial matric
Where does FA synthesis occur?
Cytosol
Where does MalonylCoA inhibit?
CPT I
Which shuttle is used in FA synthesis?
CItrate shuttle
Which shuttle is used in FA oxidation?
Carnitine
What is the rate determining enzyme in FA oxidation?
Carnitine acyltransferase I (CPTI)
What is the rate limiting enzyme in FA synthesis?
AcCoA carboxylase (ACC)
What step is AcCoA denhydrogenase used in for FA oxidation?
Step 1: FattyacylCoA to trans FattyenolCoA
What enzymes are needed for oxidation of unsaturated FAs?
- enoylCoA isomerase
- 2,4-dienoyl reductase
- acylCoA dehydrogenase
What does B-oxidation of odd-chain FAs produce?
AcCoA + propionylCoA
How does propionylCoA enter the TCA cycle?
PropionylCoA—–> MethylmalonylCoA + B12—->Succinyl CoA
What does Beta Oxidation produce?
AcCoA
How many each mol of AcCoA produces how many ATPs?
10
Every 2 carbons of a FA produces?
1 FADH–>2 ATP, 1 NADH—>3 ATP, and 1 AcCoA–>10 mol of ATP. =15 moles
omega-oxidation occurs where in the cell?
Smooth Endoplasmic Reticulum
Where are VLFAC oxidized?
Peroxisomes
What are the fates of AcCoA?
- Ketone bodies (liver)
2. TCA cycle
What are the two main ketone bodies?
- acetoacetate
- Beta-hydroxybutyrate
(used in muscle and brain)
What stimulates synthesis of Ketone Bodies in liver?
High ration of NADH/NAD which slows down TCA cycle causing AcCoA buildup
Which enzyme is needed to use ketones?
thiotransferase which is not in the liver
What is the purpose of ketone bodies?
Spares muscles during starvation
