膜结构及其转运功能11课件.pptVIP

（1）同向转运近端肾小管上皮（Na+-Glucose）小肠黏膜上皮（2Na+-Glucose）Na+-葡萄糖同向转运体（1）同向转运Na+-氨基酸肾小管上皮细胞肾小管上皮细胞甲状腺上皮细胞（1）反向转运Exchangers(alsoknownasantiporters)arefoundinmanydifferentcellsandtissuesandperformavarietyofimportantphysiologicalfunctions.Threeexamplesareshownhere.肠黏膜上皮细胞葡萄糖继发性主动转运模式图Howaboutlargemolecules?Movinglargemoleculesintooutofcellthroughvesicles消耗能量、主动Exocytosis-出胞=themovementofasubstancebyavesicletotheoutsideofacellConstitutiveExocytosis-持续性出胞RegulatedExocytosis-调节性出胞endocytosis–入胞=themovementofasubstanceintoacellbyavesiclephagocytosis–吞噬=“cellulareating”Pinocytosis-吞饮=“cellulardrinking”（四）膜泡运输（Vesiculartransport）301.出胞（Exocytosis)

Largemoleculesthataremanufacturedinthecellarereleasedthroughthecellmembrane.InsideCellCellenvironment31ExocytosisExocyticvesicleimmediatelyafterfusionwithplasmamembrane.copyrightcmassengaleExocytosis:regulatedandconstitutivesecretion.Duringsecretion,vesiclesderivedfromthetransfaceoftheGolgicomplexwillfusewiththeplasmamembrane,dumpingtheircontentsintotheextracellularenvironment.Inconstitutivesecretion,secretoryvesiclesarecontinuouslydeliveredtotheplasmamembrane,wheretheyrapidlyfusewiththemembrane.Inregulatedsecretion,thevesiclesderivedfromthetransfaceoftheGolgicomplexaggregateandconcentratetheircontentsinthecytoplasm,wheretheyremainuntilthecellhasreceivedtheappropriatesignal.Then,thesecretoryvesiclesfusewiththeplasmamembrane.Thecontentsofthesetwoclassesofsecretoryvesiclesaredistinct.（1）持续性出胞ConstitutiveExocytosis（2）调节性出胞RegulatedExocytosis例：小肠黏膜杯状细胞分泌黏液例：动作电位达到神经末梢引起神经递质的释放（1）Phagocytosis（吞噬）Usedtoengulflargeparticlessuchasbacteria,etc.intovesicles(Celleating)2.入胞（Endocytosis）34PhagocytosisAbouttoOccurcopyrightcmassengaleCellformsaninvaginationMaterialsdissolveinwater