lipid metabolismguralnl/gural/451lipid metabolism.pdfoleate: double bond at cis 9 ... oxidation of...
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![Page 1: Lipid Metabolismguralnl/gural/451Lipid Metabolism.pdfOleate: double bond at cis 9 ... Oxidation of Unsaturated Fatty acids • New enzymes • enoyl CoA isomerase • 2,4 dienoyl-CoA](https://reader035.vdocuments.net/reader035/viewer/2022062414/5e55db842343c4424e0191cf/html5/thumbnails/1.jpg)
Lipid Metabolism• Lipid nomenclature• Oxidation of Fatty
acids• β-oxidation• Ketone Bodies
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Lipid nomenclature• Fatty acids • triacylglycerols: know structure • phospholipids • waxes • sphingolipids• Glycosphingolipids• Isoprenoids• Steriods• Nomenclature • saturated: palmitate, stearate,
no double bonds • unsaturated: palmitoleate,
Oleate: double bond at cis 9 position
• polyunsaturated • Melting points: saturated vs
unsaturated
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Oxidation of Fatty acids• Know equation for palmitate:
C16H32O + O2 ---> CO2 + H2O
• Comparison of glucose with palmitate for ATP production and energy yield
• Mobilization of Triacylglycerols from adipose tissue – hormonal control: glucagon,
epinephrine – lipases – transport by lipoproteins – fate of glycerol
• transport into cytoplasm of cell
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Digestion of lipid in diet
• Triacylglycerols from diet • broken down in small intestine • lipases • bile salts • transport to adipose tissue
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Mobilization of Triacylglycerols
– hormonal control of lipolysis: glucagon, epinephrine
– lipases – transport by
lipoproteins – transport into
cytoplasm of cell– Insulin inhibits
lipolysis
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Breakdown of triacylglycerides
fate of glycerol
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β-oxidation
• occurs in mitochondria
• uses FAD and NAD • produces acetyl CoA
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acyl CoA synthetase
• two step reaction • ATP + FA ---> AMP-FA • AMP-FA + CoASH ------> FA-CoA + AMP
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Transport into mitochondria
• Carnitine shuttle • CAT I/II • Translocase reaction
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β-oxidation
• Acyl CoA dehydrogenase
• enoyl-CoA hydratase• L-hydroxyacyl
dehydrogenase• ketoacyl-CoA thiolase• Repeat steps
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Summary of Reactions
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Energy production
• NADH and FADH from B-oxidation
• TCA cycle from acetyl CoA
• Total net yield is minus 2 ATP from activation
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Oxidation of Unsaturated Fatty acids
• New enzymes• enoyl CoA isomerase• 2,4 dienoyl-CoA
reductase
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Unsaturated Fatty acids
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Oxidation of odd chain fatty acids
• form propionyl CoA • produce succinyl CoA
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Ketone Bodies
• Acetoacetate• Acetone • B-hyroxybutyrate• HMG CoA synthase
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Ketone bodies and diabetes