Lecture 2

• Fatty acids transported in plasma as unesterfied form of free fatty acids
• Lauric acid as 12C
• Myristic acid has 14C
• Palmitic acid has 16C
• Stearic acid has 18C
• Arachidic acid has 20C
• Behenic acid has 22C
• Lignoceric acid has 24C
• Palmitoleic acid has 16C and a double bond at 9
• Oleic Acid has 18C and a double bond at 9
• Linoleic acid has 18C and a double bond at 9,12
• alpha-linoleic acid has 18C and a double bond at 9,12,15
• Gamma-linoleic acid has 18C and a double bond at 6,9,12
• Arachidonic acid has 20C and a double bond at 5,8,11,14
• EPA has 20C and a double bond at 5,8,11,14,17
• Nervonic acid has 24C and a double bond at 15
• w-6 linoleic acid
• W-3 alpha Linolenic acid
• Long chain free fatty acids combine with albumin and attach to FABP. short chain Fatty acids are water soluble and exist as unionized acid or fatty acid anion
• Oxidation if fatty acids occur in the mitochondria and are an aerobic process
• The Fatty acid is activated which uses 2ATP. Transport of fatty acids is done by cranitine palmitoyltransferase-1 to carnitine-acylcarnitine translocase to carnitine palmitoyltransferase-2
• Acyl-COA dehydronase uses FAD and releases FADH2which is then used in the ETC. This generates 1.5 ATP
• Beta-hydroxy CoA dehydrogenase generates 2.5ATP and NADH
• Oxidation of odd-chain fatty acid continues until 3C propionly-COA residue only glucogenic part. Propionly COA carboxylase needs biotin
• Methyl-malonyl COA mutase needs Vitamin B12
• Oxidation of long fatty acids occurs in peroxixomes leads to acetyl-CoA and H2O2 and ends at octonyl-CoA
• Alpha oxidation and W oxidation (catalysed by cytochrome P-450) occurs in the brain. Apllha oxidation of branched chain in peroxisimes.
• Oxidation of unsaturated at uneven uses 1.5ATP for every double bond and gives 2.5ATP
• oxidation of unsaturated gives 1.5ATP and 2.5ATP

  
• B oxidation on unsaturated

  
• carnitine deficiency can occur particularly in the newborn,

  symptoms include hypoglycemia and lipid accumulation with

  muscular weakness
• Iinherited CPT-I deficiency affects only the liver, resulting in

  reduced fatty acid oxidation and ketogenesis, with hypoglycemia
• CPT-II deficiency affects primarily skeletal muscle and, when

  severe, the liver
• inherited defects in the enzymes of β-oxidation and ketogenesis

  lead to nonketotic hypoglycemia, coma, and fatty liver (eg. acute

  fatty liver of pregnancy)
• jamaican vomiting sickness is caused by eating the unripe fruit

  of the akee tree, which contains a toxin, hypoglycin, inhibiting β-

  oxidation and causing hypoglycemia
• Refsum’s disease is a rare neurologic disorder due to a defect

  that causes the accumulation of phytanic acid, which blocks β-

  oxidation
• Zellweger’s syndrome occurs in individuals with a rare inherited

  absence of peroxisomes in all tissues, C26–C38 acids are

  accumulated in brain tissue
• Regulation of long chain fatty acid Acyl-CoA, glucagon inhibit acetyl-CoA carboxylase and insulin activated it. MalonYSL-CoA inhibits Carnitines palmitoyl-transferase 1
• Acetoacetate and D-hydroxybutyrate are exported to the heart, skeletal muscle,kidney and brain
• Acetone not used to produce energy