Please enable JavaScript.
Coggle requires JavaScript to display documents.
Fat metabolism - Coggle Diagram
Fat metabolism
The energy produced by fatty acid oxidation
For every fatty acid cycle, 1 NADH and 1 FADH2 (
3 +2= 5 ATP
) produced. For N carbon fatty acid oxidation, a number of cycles is (N/2-1).
Thus number of ATP's produced = (N/2-1)*5= (5N/2)-5
Every Acetyl CoA produces 3 NADH, 1 FADH2, and 1 ATP in TCA cycle (
3x3 + 2x1 +1= 12 ATP
). For N carbon fatty acid oxidation, number of acetyl coA produced are (N/2).
Thus number of ATP's produced = (N/2)x12= 6N
N Carbon fatty acid will yield (N/2) Acetyl CoA and will require (N/2 -1) cycles of beta oxidation
For conversion of fatty acid to fatty acyl coA
1 ATP
is required
1 molecule of NADH produces 3 ATP and 1 molecule of FADH2 produces 2 ATP
NET ATP produced per cycle
=(5N/2) -5 +6N -1 ATP=
[(17N/2) -6] ATP
β-oxidation
Fatty acids are utilized by heart muscles, liver and skeletal muscles
Occurs in mitochondrial matrix
Even chain fatty acid metabolism
Steps
This fatty acid is converted to Fatty acyl CoA so that it cannot escape the cell
Fatty acyl CoA synthetase
1 molecule ATP utilized
Fatty acyl CoA is converted to Fatty acyl Carnitine so that it can enter the mitochondria
Carnitine acyl transferase 1(CAT1)
present on the outer membrane of mitochondria which is involved in conversion as well as translocation of Fatty acyl carnitine
Fatty acyl carnitine is reconverted to Fatty acyl CoA and Carnitine is recycled into the outer membrane of mitochondria
Carnitine acyl transferase 2(CAT2)
present on the inner membrane of mitochondria
Fatty Acyl CoA (N carbons) + FAD to Enoyl CoA
Acyl CoA dehydrogenase
FADH2 released
Enoyl CoA +H2O to β-hydroxy Acyl CoA
Enoyl CoA hydratase
β-hydroxy Acyl CoA + NAD to β-keto Acyl CoA +NADH
β-keto Acyl CoA dehydrogenase
β-keto Acyl CoA (N carbons) +CoA to Fatty acyl CoA (N-2 Carbons) + Acetyl CoA
Thiolase
Fatty acyl CoA(N-2 carbons) again undergoes the process of β-oxidation and this goes on until we get all acetyl CoA
First fatty acid enters the cell
Odd chain fatty acid metabolism
All the same steps as even chain fatty acid metabolism except in the last step where
propionyl CoA
is produced instead of Acetyl CoA
Propionyl CoA +ATP to Methyl Malonyl CoA +ADP
Propionyl CoA carboxylase
Methyl Malonyl CoA to Succinyl CoA
Methyl Malonyl CoA mutase
Reaction requires Vitamin B12
Succinyl CoA
converted to oxaloacetate in turn converted to Pyruvate which can be used for
Gluconeogenesis
It can also required for heme and other porphyrin synthesis
Metabolism in Peroxisomes
This H2O2 is converted back to O2 and H2O since it is dangerous for the cell
Catalase
All steps similar to even chain fatty acid metabolism except the fact that FADH2 produced is used to convert (Oxygen + Water) into Hydrogen peroxide
Diseases
Medium chain acyl dehydrogenase deficiency(MCAD)
No fatty acid oxidation leading to fatty acid accumulation
hypoglycemia
vomiting, sleepiness
X linked Adrenoleuko dystrophy
No functional fatty acid transporters on the cell and thus fatty acid accumulation in the cell
visual and behavioral disturbances