(3)脂肪酸氧化与ATP Stage 2 合成 CHa oxidation CH. 8 Acetyl-CoA 与葡萄糖的氧化分解相似 CH 脂肪酸的氧化分解也由三 个阶段组成: CH 第一阶段:脂肪酸的β-氧 Citric acid cycle 化; CHe CH2 第二阶段:产生的乙酰辅 H 64e CHA 16C0 O2 酶A进入三羧酸循环彻底 C=0 氧化。 第三阶段:前两个阶段产 stage 3 L NADE, FADH 生的还原性辅酶进入呼吸 链,经电子传递,最终将 2H'+o2 Respiratory (electron transfer) 氢和电子交给分子氧生产 chain→+→ H2o 水,释放出的能量合成 +Pi ATP ATP
（3）脂肪酸氧化与ATP 合成 ◆ 与葡萄糖的氧化分解相似， 脂肪酸的氧化分解也由三 个阶段组成： ◆ 第一阶段：脂肪酸的-氧 化； ◆ 第二阶段：产生的乙酰辅 酶A进入三羧酸循环彻底 氧化。 ◆ 第三阶段：前两个阶段产 生的还原性辅酶进入呼吸 链，经电子传递，最终将 氢和电子交给分子氧生产 水，释放出的能量合成 ATP
Yield of aTP during oxidation of one molecule of palmitoyl-Coa to cO2 and ho Enzyme catalyzing NADH or fadh Number ofatP ultimately oXidation step formed formed Acyl-CoA dehydrogenase 7 FADH 10.5 β- Hydroxyacyl-COA 7 NADH 17.5 dehydrogenase Isocitrate dehydrogenase 8 NADH 20 a-Ketoglutarate dehydrogenase 8 NADH 0 Succinyl-CoA synthetase succinate dehydrogenase 8, 12 Malate dehydrogenase 8 NADH 20 108
Yield of ATP during oxidation of one molecule of palmitoyl-CoA to CO2 and H2O Enzyme catalyzing oxidation step NADH or FADH2 formed Number of ATP ultimately formed Acyl-CoA dehydrogenase 7 FADH2 10.5 β-Hydroxyacyl-CoA dehydrogenase 7 NADH 17.5 Isocitrate dehydrogenase 8 NADH 20 α-Ketoglutarate dehydrogenase 8 NADH 20 Succinyl-CoA synthetase 8 * Succinate dehydrogenase 8 FADH2 12 Malate dehydrogenase 8 NADH 20 Total 108
3.不饱和脂肪酸的分解代谢 Oxidation of unsaturated fatty acids requires one or two auxillary enzymes, an isomerase and a reductase
3. 不饱和脂肪酸的分解代谢 ◆Oxidation of unsaturated fatty acids requires one or two auxiliary enzymes, an isomerase and a reductase
Odd-position single double bond S-CoA Oley l-COA B oxidation (three cycles)N>3 Acetyl-CoA Odd-numbered double bonds are handled by H the isomerase S-CoA Dodecenoyl-CoA Enoyl-COA Isomerase cis-△3 is converted to trans-△2 S-COA H trans-△2 Dodecenoyl-COA B oxidation (five cycles) 6 Acetyl-CoA
Odd-position single double bond Enoyl-CoA isomerase cis-3 is converted to trans-2 Odd-numbered double bonds are handled by the isomerase
亚油酰-COA Linoleoyl-CoA S-COA B oxidation (three cycles) 3 Acetyl-CoA S-CoA Czs-△3 ,Cs-△ enovl-COA N)I1毛 S-CoA trans-△2,cis-△6 B oxidation (one cycle. and AcetvI-coa Even-numbered double bonds are first oxidation of second cyele handled by the reductase and the -CoA somerase O trans-△2 2, 4-dienoyl-CoA NADPH H Reductase NADP+ A trans-△2,cis-△4 structure is converted o-o to a trans-4 structure(consuming NADPH S-CoA trans-4s enovl-CoA S-Co s oxidation (four cycles) 5 AcetyI-CoA
2,4-dienoyl-CoA Reductase A trans-2 , cis-4 structure is converted to a trans-3 structure (consuming NADPH) 亚油酰-CoA Even-numbered double bonds are handled by the reductase and the isomerase