Lipids 2 Flashcards
What process does the body use to breakdown FA’s to produce energy?
B-Oxidation
Where does b-oxidation occur?
Mitochondrial matrix
What does b-oxidation produce?
- Acetyl CoA
- FADH2
- NADH
What are the 3 stages of b-oxidation called?
- Activation
- Transport
- Degradation
Where are the FA’s activated?
Cytosol
Where are the FA’s transported to?
Inner mitochondrial membrane
What happens to the FA during activation?
Has a CoA group attached to it
What does the attachment of the CoA group produce?
Acyl CoA
What replaces the CoA of Acyl CoA to allow it to move into the mitochondrial matrix?
Carnitine
How does Acyl CoA enter the outer membrane of the mitochondria?
Can pass freely into it
Once inside the outer mitochondrial membrane, what enzyme replaces the CoA with carnitine?
Carnitine Palmytol Transferase 1
What transporter does acyl carnitine use to enter the mitochondrial matrix?
- Transferase
What happens to the acyl carnitine when it arrives in the matrix?
- Carnitine is removed by carnitine palmytol transferase 2 and CoA is added
What happens to the carnitine removed by carnitine palmytol transferase?
It is moved back through another transferase enzyme into the outer membrane
What is carnitine palmytol inhibited by to stop synthesis and degradation at the same time?
Malonyl CoA
What happens if there is a deficiency of CAT-1?
No b-ox
- Hypoglycaemia
How do you treat hypoglycaemia?
- IV glucose
- Consume short chain FA’s
Why does consumption of shorter chained FA’s help treat hypoglycaemia?
They can diffuse into the matrix
What are the 4 main steps of degredation? And what does each stage produce?
- Dehydrogenation (FADH2)
- Hydration
- Dehydrogenation (NADH)
- Thiolysis (acetyl CoA)
What does each cycle of B ox produce?
- 1 acetyl CoA
- FA 2 carbons shorter than the original
How much acetyl CoA, NADH and FADH2 does complete b - ox of palmitate produce?
- 7 acetyl CoA
- 8 FADH2
- 8 NADH
What is the ATP yield per FADH2?
2
What is the ATP yield per NADH?
3
What is the ATP yield per acetyl CoA?
12
What happens to FA’s longer than 22 carbons before B oxidation can occur?
Pre beta oxidation in the peroxisome
Why can FA’s not be used to produce glucose?
Acetyl CoA back to pyruvate is very unfavourable
If there is an excess of acetyl CoA what is it converted to?
Ketone bodies
How many acetyl CoA’s are used to produce a ketone body?
2
Why is the conversion of acetyl CoA to ketone bodies useful?
Some tissues can’t use FA’s for energy production but can use ketone bodies?
What is an important organ that can’t utilise FA’s for energy?
The brain
What happens during uncontrolled diabetes?
- Body starts producing ketones
- Ketonemia and academia result
- Blood pH drops
- COMA AND DEATH
