· Fatty acids catabolism by ß-oxidation :
- Activation of fatty acid:
- Formation of fatty acylcarnitine and its transport into mitochondria;
- Steps of ß-oxidation;
- Oxidation of odd chain fatty acids;
- Oxidation of unsaturated fatty acids;
- The energy yield from ß-oxidation of saturated and unsaturated fatty acids;
- Regulation of ß-oxidation.
· Oxidation of glycerol and its energy yield.
· The energy yield from triacylglycerol degradation.
· Acetyl-CoA metabolism in liver.
· Fatty acid synthesis :
- Steps of the process,
- Fatty acid synthase complex,
- Regulation of fatty acids synthesis.
· Synthesis and mobilization of adipose and liver triacylglycerols. Hormonal regulation
· Metabolism of glycerophospholipids and sphingolipids
· Estimation of total blood serum lipids by sulfovanilline reagent
FATTY ACIDS CATABOLISM BY ß-OXIDATION
1. Study ß- oxidation of fatty acids (p.49, 357; Activation, transport into mitochondria, reactions, substrates, products, enzymes, 360-364)
2. Note: Peripheral tissues receive fatty acids from blood by three pathways:
a) Free fatty acids from adipose tissue are transported by serum blood albumin,
b) Lipoprotein lipase releases free fatty acids from chylomicrons,
c) Lipoprotein lipase releases free fatty acids from VLDL
9. Read about the energy yield from ß-oxidation of saturated (p.362-363) and unsaturated fatty acids (p.364, q.23.1; p.365, A.23.1).
10. Memorize: energetics of fatty acid oxidation:
Fatty acid (n carbons) undergoes n/2-1 times ß-oxidation and produces n/2 molecules of acetyl-CoA. Each time ß-oxidation produces 5ATP (from NADH and FADH2 in ETC).
A) Total number of ATP formed by ß-oxidation = ( n/2-1)*5
B) Total number of ATP formed on oxidation of acetyl-CoA through TCA cycle = (n/2) *12
C) 2 ATP utilized for initial activation of fatty acid
Net total yield = [ ( n/2-1)*5] +[ (n/2) *12] – 2
OXIDATION OF GLYCEROL AND ITS ENERGY YIELD
1. Study the convertion of glycerol to dihydroxyaceton phosphate (p.428, fig.27.9).