第一节 脂类消化吸收和转运.ppt

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1、第八章脂类代谢脂类（lipid）甘油三酯（triacylglycerol,triglyceride）必需脂肪酸（essentialfattyacid）磷脂（phospholipid）固醇（sterol）胆固醇（cholesterol）KeyWords脂类脂肪（甘油三酯）类脂磷脂类固醇类结合脂类前列腺素萜类固醇：如：胆固醇等固醇衍生物：如：胆汁酸、VD、性激素等糖脂脂蛋白脂肪（甘油三酯）饱和脂肪酸硬脂酸18:0CH3(CH2)16COOH软脂酸16:0CH3(CH2)14COOHR：脂肪酸残基不饱和脂肪酸油酸18:

2、1△9cCH3(CH2)7CH=CH(CH2)7COOH亚油酸18:2△9c,12cCH3(CH2)4(CH=CHCH2)2(CH2)6COOH亚麻酸18:2△6c,9c,12cCH3(CH2)4(CH=CHCH2)3(CH2)3COOH必需脂肪酸1-硬脂酰，2-亚油酰，3-软脂酰-甘油结构举例：甘油三酯的生物学功能重要的能源物质许多器官组织的保护层Fatstoresincells.(a)Crosssectionoffourguineapigadipocytes（脂肪细胞）,showinghugefatdropl

3、etsthatvirtuallyfillthecells.Alsovisibleareseveralcapillariesincrosssection.(b)Crosssectionofacotyledon（子叶）cellfromaseedoftheplantArabidopsis.Thelargedarkstructuresareproteinbodies,whicharesurroundedbystoredoilsinthelight-coloredoilbodies.Thespermwhale’sheadi

4、sverylarge,accountingforoverone-thirdofitstotalbodyweight.About90%oftheweightoftheheadismadeupofthespermacetiorgan（鲸脑）,ablubberymassthatcontainsupto3,600kg(about4tons)ofspermacetioil（鲸油）,amixtureoftriacylglycerolsandwaxescontaininganabundanceofunsaturatedfatt

5、yacids.Thismixtureisliquidatthenormalrestingbodytemperatureofthewhale,about37℃,butitbeginstocrystallizeatabout31℃andbecomessolidwhenthetemperaturedropsseveralmoredegrees.SpermWhales:FatheadsoftheDeep抹香鲸磷脂饱和脂肪酸不饱和脂肪酸甘油磷脂类鞘磷脂类甘油磷脂结构通式：生物学功能：生物膜的组分极性头部非极性尾部心磷脂（双

6、磷脂酰甘油）磷脂酸脑磷脂（磷脂酰乙醇胺）卵磷脂（磷脂酰胆碱）磷脂酰丝氨酸磷脂酰甘油磷脂酰肌醇Fluidmosaicmodelformembranestructure（生物膜的流动镶嵌模型）脂双层类固醇类胆固醇酯（3-OH与RCOOH结合）（甾核）91234567810111213141516171819胆固醇（5-胆甾烯-3-醇）（参与生物膜的形成）（促进脂肪消化吸收）第一节脂类消化吸收和转运KeyWords乳糜微粒（chylomicron）脂蛋白（lipoproteins）载脂蛋白（apo-lipoprote

7、ins）脂性食物（甘油三酯少量磷脂、胆固醇酯）肠蠕动胆汁乳化乳化微粒胰脂酶等甘油一酯脂肪酸溶血磷脂胆固醇（脂解产物）乳糜微粒甘油三酯磷脂胆固醇（酯）扩散入肠重合成一、脂类的消化和吸收血液载脂蛋白Molecularstructureofachylomicron（乳糜微粒）Thesurfaceiscoveredwithalayerofphospholipids,withheadgroupsfacingtheaqueousphase.Tri-acylglycerolssequesteredintheinteriorma

8、keupmorethan80%ofthemass.Severalapo-lipoproteins（载脂蛋白）thatprotrudefromthesurfaceactassignalsintheuptakeandmetabolismofchylomicroncontents.Thediameterofchylomicronsrangesfromabout100toabou