PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16One cycle of β-oxidation – for saturated FASlide 18Slide 19Slide 20Slide 21Slide 22Fatty Acid Oxidation is an Important Source of Metabolic Water for Some AnimalsHow Are Odd-Carbon Fatty Acids Oxidized?Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Step 2-Part 1 - The Carboxylation of BiotinSlide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Slide 61Slide 62Slide 63Slide 64Slide 65Slide 66Slide 67Slide 68Lecture 20- Chapters 27 & 28Fatty Acid MetabolismLecture 20- Chapters 27 & 28Fatty Acid MetabolismThe hummingbird’s tremendous capacity to store and use fatty acids enables it to make migratory journeys of remarkable distances.The hummingbird’s tremendous capacity to store and use fatty acids enables it to make migratory journeys of remarkable distances.1OutlineOutline Fatty acid catabolism:- β-oxidation of saturated (even C) fatty acids and the ATP count - β-oxidation of saturated (uneven C) fatty acids- β-oxidation of polyunsaturated fatty acids- Ketone bodiesFatty acid biosynthesis- Overview- How the cell ensures supply of the precursors acetyl-CoA and NADPH- Steps of biosynthesis- Overall equation for the synthesis of one molecule of palmitic acid (16:0)- Regulation of fatty acid metabolism (allosteric, covalent, hormonal) Fatty acid catabolism:- β-oxidation of saturated (even C) fatty acids and the ATP count - β-oxidation of saturated (uneven C) fatty acids- β-oxidation of polyunsaturated fatty acids- Ketone bodiesFatty acid biosynthesis- Overview- How the cell ensures supply of the precursors acetyl-CoA and NADPH- Steps of biosynthesis- Overall equation for the synthesis of one molecule of palmitic acid (16:0)- Regulation of fatty acid metabolism (allosteric, covalent, hormonal)2Triaglyceride as Fuel Triaglyceride as Fuel EsterR-C-OR′=OTriglyceride/triacylglycerolsTriglyceride/triacylglycerols3AdipocyteAdipocyte4Lipid DegradationLipid Degradation+56glucoseglucoseHydrolysis (Lipolysis) of Triacylglycerols in an AdipocyteHydrolysis (Lipolysis) of Triacylglycerols in an AdipocyteATGLATGLHS lipaseHS lipaseMAG lipaseMAG lipasealbuminalbuminFAFAAdipose cellAdipose cell7Glycerol can enter the glycolysis/gluconeogenesis pathwayGlycerol can enter the glycolysis/gluconeogenesis pathway8glucoseglucoseHydrolysis (Lipolysis) of Triacylglycerols in an AdipocyteHydrolysis (Lipolysis) of Triacylglycerols in an AdipocyteATGLATGLHS lipaseHS lipaseMAG lipaseMAG lipasealbuminalbuminFAFAAdipose cellAdipose cellMuscle, kidney and heart9Fatty Acid CatabolismFatty Acid Catabolism1. Activation of Fatty acid with CoA by Acyl CoA synthase on outer membrane of mitochondria2. Transport of activated fatty acid into mitochondrial matrix via Translocase3. β-oxidation cycle of saturated even-C fatty acid4. Catabolism of uneven-C saturated fatty acid5. Catabolism of unsaturated fatty acid (double bonds)1. Activation of Fatty acid with CoA by Acyl CoA synthase on outer membrane of mitochondria2. Transport of activated fatty acid into mitochondrial matrix via Translocase3. β-oxidation cycle of saturated even-C fatty acid4. Catabolism of uneven-C saturated fatty acid5. Catabolism of unsaturated fatty acid (double bonds)10Activation of Fatty acidsActivation of Fatty acidsααββγγAcyl CoA synthaseAcyl CoA synthasePPi = pyrophosphatePPi = pyrophosphatePi = orthophosphatePi = orthophosphate11Fatty Acids are linked to Coenzyme A before they are oxidizedFatty Acids are linked to Coenzyme A before they are oxidized1.1.2.2.12The Acyl-CoA Synthetase activates fatty acids for β-oxidation. The Acyl-CoA Synthetase activates fatty acids for β-oxidation. Acyl-CoA + AMP +PPATP∆G°’ for ATPAMP + PP= -32.3 kJ/mol= -32.3 kJ/mol∆G°’ for acyl-CoA synthesis = +31.5 kJ/mol= +31.5 kJ/molNet ∆G°’= -0.8 kJ/mol= -0.8 kJ/mol13+Fig. 23-8a, p. 703Transfer of acyl CoA to inner mitochondrial spaceTransfer of acyl CoA to inner mitochondrial spaceAcyl CoAAcyl CoAAcyl carnitineAcyl carnitine14Fig. 23-8b, p. 703Transfer of Acyl carnitine from inner mitochondrial space to matrixTransfer of Acyl carnitine from inner mitochondrial space to matrixAcyl CoAAcyl CoAAcyl carnitineAcyl carnitine15Reduced Oxidizedβ-oxidation converts the β-carbon of Fatty acid Chain from reduced to oxidized formβ-oxidation converts the β-carbon of Fatty acid Chain from reduced to oxidized formCHHβOCβFAD+NAD+FADH2+NADHβ-oxidation16One cycle of β-oxidation – for saturated FAOne cycle of β-oxidation – for saturated FAAcetyl CoAAcetyl CoAAcyl CoAAcyl CoAPalmitic acid (C-16) (saturated, even C)Palmitic acid (C-16) (saturated, even C)C-14 fatty acidC-14 fatty acid17Each β cycle of oxidation involves four reactionsEach β cycle of oxidation involves four reactionsβ oxidationoxidationoxidationoxidationoxidationhydrationhydrationcleavagecleavageFADH2FADH2NADHNADH18Reactions 1 &2: Dehydrogenation (Oxidation) +Hydration Reactions 1 &2: Dehydrogenation (Oxidation) +Hydration Acyl CoA dehydrogenaseAcyl CoA dehydrogenaseEnoyl CoA hydrataseEnoyl CoA hydratase1.1.2.2.19+3.3.4.4.Reactions 3 & 4: Dehydrogenation + Cleavage of the Cα – Cβ bondReactions 3 & 4: Dehydrogenation + Cleavage of the Cα – Cβ bondL-3-Hydroxyacyl Co AdehydrogenaseL-3-Hydroxyacyl Co Adehydrogenaseβ-ketothiolaseβ-ketothiolase20Last round (#7) The first two rounds in the degradation of palmitate. The first two rounds in the degradation of palmitate.CoA21β oxidation: Total ATP yield on complete oxidation of one molecule of palmitic acid (16 carbons)β oxidation: Total ATP yield on complete oxidation of one molecule of palmitic acid (16 carbons)Note: - * Subtracting 2 ATP equivalent that was used up for the fatty acid activation- Each round of TCA cycle produces 3 NADH, 1 FADH2 and 1 ATPNote: - * Subtracting 2 ATP equivalent that was used up for the fatty acid activation- Each round of TCA cycle produces 3 NADH, 1 FADH2 and 1 ATP31 NADH x 2.5 ATP/NADH = 77.5 ATP15 FADH2 x1.5 ATP/FADH2 = 22.5 ATPTotal ATP yield = 77.5 + 22.5 + 8 -2* = 106+ 123 H2OTotal ATP yield = 77.5 + 22.5 + 8 -2* = 106+ 123 H2O22Fatty Acid Oxidation is an Important Source of Metabolic Water for Some AnimalsFatty Acid Oxidation
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