Fatty acid oxidation Flashcards
What is fatty acid oxidation/beta oxidation used for?
To convert fatty acids into acetyl CoA for use in the Kreb’s cycle
How are fatty acids converted to acyl CoA?
1) The fatty acids are catalyzed to acyl-coA in the cytoplasm.
Fatty acid + ATP + CoA = Acyl-coA + PPi + AMP
How is the acyl-CoA transported into the inner mitochondria membrane?
2) The acyl-coA is transported into the inner mitochondria membrane via an acyl-carnitine intermediate.
This is generated by the action of carnitive acyltransferase I (CAT I), an enzyme in the outer mitochondrial membrane.
3) Once in the mitochondria matrix carnitine acyltransferase II (CATII) catalyses the regeneration of the fatty acyl-CoA molecule
How does beta-oxidation work?
Each round of beta-oxidation removes 2 carbon atoms from the fatty acyl-coA molecule and produces:
1 mole of NADH, 1 mole of FADH2, 1 mole of acetyl CoA
a) The fatty acyl-CoA molecule first undergoes oxidation (loss of 2H that reduces FAD =3ATP in the electron transport chain)
b) Next the fatty acyl-CoA molecule undergoes hydration (gains H2O)
c) Then oxidation again (reduces NAD = 2ATP)
d) It then undergoes thiolysis using the enzyme CoASH, this splits the original compound into ACETYL COA (to be used in Kerbs cycle) and the remaining fatty acid that undergos beta-oxidation again
What is ketogenesis?
Ketogenesis is the production of ketone bodies in liver mitochondria due to low glucose in the body, and when glycogen storage has been used up… due to prolonged fasting, starvation or prolonged exercise
It produces ketone bodies from 2 moles of acetyle CoA and acetone (waste product)
IN skeletal muscles and other tissues these ketone bodies are then converted back to acetyl CoA to be used in the Krebs cycle to generate ATP
(Ketone bodies are also used in the brain as they can pass through the BB and acyl CoA cannot)
What are the main steps of ketogenesis? (this much detail???!)
2 acetyl CoA
Acetoacetyl CoA
HMG - CoA
Acetoacetate
Acetone + beta - hydroxybutyrate
Give an example of a fatty acid
e.g. palmitic acid
What are saturated fatty acids?
Contain no double bonds
What are unsaturated fatty acids?
Unsaturated fatty acids have one or more double bonds between carbon atoms.
What is the anion gap blood test?
The anion gap = (Na+ + K+) - (Cl- + HCO3-) where Na- is sodium, K+ is potassium, Cl- is chloride, and HCO3- is bicarbonate. The anion gap can be normal, high, or low. A high anion gap indicated metabolic acidosis, the increased acidity of the blood due to metabolic processes.
