《生物化学》课程教学课件（PPT讲稿）第十二章 脂类代谢

第十二章脂类代谢 Apolipoproteins Cholesterol Phospholipids Triacylglycerols and cholesteryl esters

第十二章脂类代谢

モ)テ（丰口）20日AFP=時事】最高時二仗体重 560卡口左記録上牛口)又又工儿.之)心è人(41) 、卡木入記録I仁登録老九石二上力分一大上。ま上之少心 è人：、200牛口の减量左達成上人上儿℃半ネ入記録 仁登绿è九石上L1。 )ベ心è人仗AFP通信I仁、「半ネ又記録I仁最老太∽大人 上L℃登録老九℃九儿。ま大、200牛口体重左减6世 ℃幸世」上語上。半ネ入記録仗)ペ心è人u左最花体重 重L八人L℃認定、2008年版少心èu)写真苍 載世、治療①過程松紹介寸石

モンテレイ（メキシコ）20日AFP＝時事】最高時には体重 560キロを記録したメキシコのマヌエル・ウリベさん（41） が、ギネス記録に登録されることが分かった。またウリベ さんは、200キロの減量を達成した人としてもギネス記録 に登録されるという。 ウリベさんはAFP通信に、「ギネス記録に最も太った人 として登録されてうれしい。また、200キロも体重を減らせ て幸せだ」と語った。ギネス記録はウリベさんを最も体重 が重い人として認定し、2008年版でウリベさんの写真を 載せ、治療の過程なども紹介する

Key Terms triacylglycerol(neutral fat, triacylglyceride) ·bile salt chylomicron acyl adenylate carnitine ·b-oxidation pathway vitamin B12(cobalamin) ·peroxisome ·ketone body acyl carrier protein (ACP) ·fatty acid synthase ·malonyl CoA acetyl CoA carboxylase

Key Terms • triacylglycerol (neutral fat, triacylglyceride) • bile salt • chylomicron • acyl adenylate • carnitine • b-oxidation pathway • vitamin B12 (cobalamin) • peroxisome • ketone body • acyl carrier protein (ACP) • fatty acid synthase • malonyl CoA • acetyl CoA carboxylase

·megasynthase ·polyketide nonribosomal peptide AMP-dependent protein kinase (AMPK) protein phosphatase 2A ·arachidonate 。prostaglandin ·eicosanoid 。l.Transducing

• megasynthase • polyketide • nonribosomal peptide • AMP-dependent protein kinase (AMPK) • protein phosphatase 2A • arachidonate • prostaglandin • eicosanoid • II. Transducing

An Overview of Fatty Acid Metabolism Fatty acid degradation and synthesis are relatively simple processes that are essentially the reverse of each other.The process of degradation converts an aliphatic compound into a set of activated acetyl units (acetyl CoA) that can be processed by the citric acid cycle (Figure 22.2).An activated fatty acid is oxidized to introduce a double bond;the double bond is hydrated to introduce an oxygen;the alcohol is oxidized to a ketone;and, finally,the four carbon fragment is cleaved by coenzyme A to yield acetyl CoA and a fatty acid chain two carbons shorter.If the fatty acid has an even number of carbon atoms and is saturated,the process is simply repeated until the fatty acid is completely converted into acetyl CoA units

An Overview of Fatty Acid Metabolism • Fatty acid degradation and synthesis are relatively simple processes that are essentially the reverse of each other. The process of degradation converts an aliphatic compound into a set of activated acetyl units (acetyl CoA) that can be processed by the citric acid cycle (Figure 22.2). An activated fatty acid is oxidized to introduce a double bond; the double bond is hydrated to introduce an oxygen; the alcohol is oxidized to a ketone; and, finally, the four carbon fragment is cleaved by coenzyme A to yield acetyl CoA and a fatty acid chain two carbons shorter. If the fatty acid has an even number of carbon atoms and is saturated, the process is simply repeated until the fatty acid is completely converted into acetyl CoA units

Fatty acid synthesis is essentially the reverse of this process.Because the result is a polymer,the process starts with monomers in this case with activated acyl group (most simply,an acetyl unit)and malonyl units (see Figure 22.2).The malonyl unit is condensed with the acetyl unit to form a four-carbon fragment.To produce the required hydrocarbon chain,the carbonyl must be reduced.The fragment is reduced,dehydrated, and reduced again,exactly the opposite ofdegradation, to bring the carbonyl group to the level of a methylene group with the formation of butyryl CoA.Another activated malonyl group condenses with the butyryl unit and the process is repeated until a C16 fatty acid is synthesized

• Fatty acid synthesis is essentially the reverse of this process. Because the result is a polymer, the process starts with monomers in this case with activated acyl group (most simply, an acetyl unit) and malonyl units (see Figure 22.2). The malonyl unit is condensed with the acetyl unit to form a four-carbon fragment. To produce the required hydrocarbon chain, the carbonyl must be reduced. The fragment is reduced, dehydrated, and reduced again, exactly the opposite ofdegradation, to bring the carbonyl group to the level of a methylene group with the formation of butyryl CoA. Another • activated malonyl group condenses with the butyryl unit and the process is repeated until a C16 fatty acid is synthesized

Triacylglycerols Are Highly Concentrated Energy Stores Fatty acids are physiologically important as(1)components of phospholipids and glycolipids,(2)hydrophilic modifiers of proteins,(3)fuel molecules,and (4) hormones and intracellular messengers. They are stored in adipose tissue as triacylglycerols(neutral fat)

Triacylglycerols Are Highly Concentrated Energy Stores • Fatty acids are physiologically important as (1) components of phospholipids and glycolipids, (2) hydrophilic modifiers of proteins, (3) fuel molecules, and (4) hormones and intracellular messengers. They are stored in adipose tissue as triacylglycerols (neutral fat)

一脂类的生理功能 ☆构成细胞膜的必要成分 ☆氧化供能：9克葡萄糖≈1克脂肪？ ☆其他功能： 保持体温 保护，固定内脏 胆固醇是生成胆汁酸，V①3，类固醇激 素的原料

一 脂类的生理功能 ☆构成细胞膜的必要成分 ☆氧化供能： 9克葡萄糖≈1克脂肪？ ☆其他功能： 保持体温 保护，固定内脏 胆固醇是生成胆汁酸，VD3，类固醇激 素的原料

脂肪酸的通式： OH H3C-(CH2)n-C-C-C=O ①

H3C-（CH2）n-C-C-C=O OH -    脂肪酸的通式：

Triglyceride Triacylglycerol