Chapter 7 Metabolism of Lipids 类脂肪:甘油+脂肪酸(三酰甘油、甘油三脂) 口 类脂:磷脂、糖脂、固醇类物质 口生物学功能 o良好的能源物质 0生物膜和细胞质的重要成分 o固醇类物质是动物激素和的前体 筏谢失调会导致疾病: 如:肥胖症、血管硬化 结石、脂肪肝。酮尿
Chapter 7 Metabolism of Lipids 脂肪：甘油+ 脂肪酸 (三酰甘油、甘油三脂) 类脂：磷脂、糖脂、固醇类物质 ❑生物学功能： o 良好的能源物质 o 生物膜和细胞质的重要成分 o 固醇类物质是动物激素和Vit D的前体 ❑代谢失调会导致疾病： 如：肥胖症、血管硬化、 结石、脂肪肝、酮尿 ❑脂类
I. Catalyzed hydrolysis of lipids drolvzed with lipase Hydrolyzate: glycerol fatty acid 甘油三脂之甘油二脂甘油单脂成甘油 H20 RCOOH H2O R, COOH H2O RCOOH 2. Hydrolyzed with phospholipase 包含:磷酸二脂酶、磷酸单脂酶。 产物:甘油二脂、磷酸、胆碱
I. Catalyzed hydrolysis of lipids 1. Hydrolyzed with lipase: Hydrolyzate: glycerol + fatty acid 甘油三脂 → 甘油二脂 → 甘油单脂 → 甘油 H2O R1COOH H2O R1COOH H2O R1COOH 2. Hydrolyzed with phospholipase: 包含：磷酸二脂酶、磷酸单脂酶。 产物：甘油二脂、磷酸、胆碱
I. Catalyzed hydrolysis of lipids 3. H drolysis of simple lipids 简单脂类包括:胆固醇、乙酰胆碱等。 胆固醇 (胆固醇脂酶)→胆固醇+脂肪酸 乙酰胆碱 (胆碱脂酶)→胆碱+乙酰
3. Hydrolysis of simple lipids: 简单脂类包括：胆固醇、乙酰胆碱等。 胆固醇 （胆固醇脂酶） → 胆固醇 + 脂肪酸 乙酰胆碱 （胆碱脂酶） → 胆碱 + 乙酰 I. Catalyzed hydrolysis of lipids
II. Catabolism of fat 1. Oxidation of glycerol: 首先,(甘油磷酸激酶+ATP)→-甘油 然后,(@甘油脱氢酶+NAD+)→二羟丙酮 糖酵解 Change of energy o Activation of glycerol I ATP o@-甘油→⑩二羟丙酮: 1 NADH+H+ 即3ATP o@二羟丙酮彻底氧化:→PA:2ATP、1NADH+H即5ATP →乙酰COA:1NADH+H 即3ATP → TCA Cycle 共12ATP TOTAL: 22 ATP
II. Catabolism of fat 1. Oxidation of Glycerol: 首先，（甘油磷酸激酶 + ATP）→ - 甘油 然后，（ 甘油脱氢酶 + NAD+ ）→ 二羟丙酮 糖酵解 Change of energy: o Activation of glycerol: -1 ATP o -甘油→ 二羟丙酮： 1 NADH+ H+ 即3 ATP o 二羟丙酮彻底氧化：→PA: 2 ATP、 1 NADH+H+ 即5 ATP →乙酰CoA: 1 NADH+ H+ 即3 ATP →TCA Cycle: 共12 ATP TOTAL: 22 ATP
II Catabolism of fat 2. Cata bolism of fatty acid listory: >B-oxidation theory(Knoop 1904) >activated" acetyl acid Lehninger 1940S) >activated'" acetyl acid is acetyl CoA ( Lynen 1951)
2. Catabolism of fatty acid: ❑History: ➢-oxidation theory (Knoop 1904) ➢“activated” acetyl acid (Lehninger 1940S) ➢“activated” acetyl acid is acetyl CoA (Lynen 1951) II. Catabolism of fat
2. Cata bolism of fatty acid 口 Process:β- oxidation of saturated fatty acid (Fig) Acivation of fatty acid-fatty acyl-coA >Dehydrogenation(B-oxidation >hydration > Dehydrogenation(B-oxidation) >Thiolysis split
❑Process: -oxidation of saturated fatty acid (Fig.) ➢Acivation of fatty acid– fatty acyl-CoA ➢Dehydrogenation (-oxidation) ➢Hydration ➢Dehydrogenation (-oxidation) ➢Thiolysis \split 2. Catabolism of fatty acid
2. Cata bolism of fatty acid 口 Concept:β- oxidation Oxidation of B-c offatty acid, which undergo 4 reactions: dehydrogenation, hydration dehydrogenationagain) and thiolysis split in turn the fatty acid chain then reduce 2C and produce/ ace tyl CoA
❑Concept: -oxidation Oxidation of -C of fatty acid, which undergo 4 reactions: dehydrogenation, hydration, dehydrogenation (again) and thiolysis \split in turn, the fatty acid chain then reduce 2C and produce 1 acetyl CoA. 2. Catabolism of fatty acid
2. Cata bolism of fatty acid 口 Position: role of carnitine B-oxidation of fatty acid occurred in mitochondria while the activation of fatty acid is in cytosol Fatty acyl-CoA carnitine> fatty acyl-carnitine CoA ( fatty acyl-CoA: carnitine fatty acyl transferase) Fatty acyl-carnitine can permeate membrane of mitochondria (Fig
2. Catabolism of fatty acid ❑Position : role of carnitine -oxidation of fatty acid occurred in mitochondria, while the activation of fatty acid is in cytosol. Fatty acyl-CoA + carnitine → fatty acyl-carnitine + CoA (fatty acyl-CoA: carnitine fatty acyl transferase) (Fig.)
2. Cata bolism of fatty acid 口 Energy Acivation of fatty acid 2 ATP >B-oxidation 1 FADH +1 NADH 5 ATP >Oxidation per acetyl CoA 12 ATP How many acetyl Coa will be produced per fatty acid? >Cn/2 acetyl CoA and (Cn/2)-/FADH NADH (It is suggested that n is even
2. Catabolism of fatty acid ❑Energy: ➢Acivation of fatty acid -2 ATP ➢-oxidation 1 FADH +1 NADH 5 ATP ➢Oxidation per acetyl CoA 12 ATP How many acetyl CoA will be produced per fatty acid? →Cn/2 acetyl CoA and (Cn/2)-1 [FADH + NADH] (It is suggested that n is even.)
2. Cata bolism of fatty acid 口 Energy:(Cont) ATP=17 Cn/2-7(n is even) e.g. Palmitate(c16) yields 129 ATP when oxidized to co, and HO The energy efficiency is 129X7.3/2340=40.24% Q1分子三硬脂酸甘油脂彻底氧化产生多少ATP? uOdd-number fatty acids--1 propionyl COA (羧化)→甲基丙二酸单酰CoA→(变位→琥珀酰CoA
2. Catabolism of fatty acid ❑Energy: (Cont.) ATP = 17 Cn/2 –7 ( n is even) e.g. Palmitate(C16) yields 129 ATP when oxidized to CO2 and H2O. The energy efficiency is 129 × 7.3 / 2340 = 40.24% Q: 1分子三硬脂酸甘油脂彻底氧化产生多少ATP? ❑Odd-number fatty acids -- 1 propionyl CoA (羧化)→甲基丙二酸单酰CoA→(变位)→琥珀酰CoA
