资源描述：
《蛋白质核酸代谢（protein and nucleic acid metabolism）》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、蛋白质核酸代谢（Proteinandnucleicacidmetabolism）Thetwelfthchapter,proteincatabolism,foodproteininthesmallintestineafteraseriesofproteaseaction,hydrolysisintoAA,canbeabsorbedbysmallintestinalepithelialcells.AAcanbefurtherbrokendownincellsandcanbesynthesizedagain,whileproteinsynthesisisleftbehind.T
2、hedegradationof1.AA.I.commonmetabolicpathways:treatmentofaminoandcarboxylgroups.Oxidativedeaminationof1.AAO2isrequiredtoparticipateinthereversiblereactiontoturntheaminogroupintoaketogroup,theproductbeingalphaketoacid,catalysedbyAAoxidase(withL-andD-,stereospecific),coenzymeFADorFMN,butnot
3、producingenergy.TheoverallreactiontypeP412,thespecificprocessforseethehandoutunderP22.AAoxidaseislowinnumberandlowinactivity,sodeaminationisnotthemaintreatmentofmostAA.However,thereisanenzymeexception:L-Gludehydrogenase,whosecatalyticreactionisseeninP413,toproduceenergy,highactivityofthis
4、enzyme,isthemaintreatmentofGluamino.2.,AAofammoniatransfer(againreiterated:enterthelaboratorytodobiochemicaltestsmustbewhiteoveralls,otherwise,refusedtoenter,andthendoanyexperimentsarerequired)Undertheactionoftransaminase,infact,theexchangereaction,theexchangeofketonegroupandaminogroup,re
5、versiblereaction.SeeP413forthereactionManyofthecellsinthemajorityoftransaminasespecies,"Guxisintransaminase,alphaketoglutarate(P413)aminoreceptortransaminationreactionisthemaintreatmentofaminoAA.Thealanineaminotransferase(P414)andaspartateaminotransferaseactivityisthehighest:Glu+,Asp+--ox
6、aloaceticacidalphaketoglutaricacidGlu+-Ala+-pyruvate,alphaketoglutarateTransaminaseneedspyridoxalorpyridoxaminephosphateascoenzyme(VB6derivatives,structure,seeP414)theyarethecarrierofamino.Transaminasewasendoenzymeinliverandheartwerethehighest,thebloodisfew,whentheliverlesions,cellpermeab
7、ilityincreased,extracellularenzymesexudation,intotheblood,thebloodtransaminaseactivityisgreatlyimproved,whichistheprinciplediagnosisofhepatitis.Combineddeaminationof3.AAIsoxidativedeaminationandammoniainoptimization,L-Gludehydrogenaseactivityishigh,somanykindsofGuxt
