动物生理学7.能量代谢与体温VIP免费

7.7.EnergyMetabolismandBodyEnergyMetabolismandBodyTemperatureTemperature7.1EnergyMetabolismEnergyMetabolism生物体内物质代谢过程中所伴随的能量的释放、转移、存储与利用，称为能量代谢（energymetabolism)EnergyMetabolismAssimilationmetabolismAssimilationmetabolismDissimilationmetabolismDissimilationmetabolismSubstantialmetabolismSubstantialmetabolismEnergymetabolismEnergymetabolism7.1.1Energysources&utilization7.1.1Energysources&utilization7.1.1.1Energysources人和动物只能利用食物中蕴藏的化学能TheProductionandfunctionofATP(adenosinetriphosphate)Directdonatorofenergy:ATPReserveformofenergy:CP鸟氨酸Glucose(1mol):aerobicoxidationyields38molATP;anaerobicglycolysisyields2molATPFat:1mol6Cfattyacidyield44molATPProtein:rarelyusedasenergydonator糖是主要供能物质，它提供人体所需能量的50%~70%；其余的能量由脂肪提供。脂肪是体内能源物质贮存的主要形式。在糖和脂肪供能不足时，蛋白质才分解用于提供能量。在被吸收的单糖中，葡萄糖占80%，通常所说的血糖是指血液中的葡萄糖。糖的分解代谢：glycolysis、aerobicrespiration,Oxygendebt脑组织所需能量一般均来自糖的有氧氧化FatisthemostconcentratedsourceoffoodenergyFatshavealittlemorethandoublethecaloriesthancarbohydratesandproteinshave.storedinadiposetissue(脂肪组织）andinmusclemuscleusesfattyacidsforfuelproduceATPmoreslowlythanCHOduringrest,provides>½theATP,butlittleduringintenseexerciseitserveswellinemergencies,whenthebodyisinneedofextrafuelFatisoftenassociatedwithcholesterolandhealthproblems.proteinproteinsplitintoaminoacidsingut,absorbed,andtransportedbybloodfirstroleisprovidingbuildingblocksformetabolicfunctionsandtissuebuildingprovides5-15%offuelforATPproduction7.1.1.2Energyutilization7.1.1.2EnergyutilizationMorethan50%transfertoheat,Morethan50%transfertoheat,Lessthan50%storeintheATP&CPLessthan50%storeintheATP&CPUtilization:synthesis&growthUtilization:synthesis&growthnerveconductionnerveconductionmuscularcontractionmuscularcontractionglandularsecretionglandularsecretionactiveabsorptionactiveabsorptionotherfunctionsotherfunctions7.1.1.2EnergyBalance7.1.1.2EnergyBalanceNeutralenergybalanceiswhenthecaloriesyoutakeinisequaltothecaloriesexpended.Weightismaintained.Positiveenergybalanceiswhenthecaloriesyoutakeinisgreaterthanthecaloriesexpended.Weightisgainedandfatstoresareincreased.Negativeenergybalance:caloriesyoutakeinislessthanthecaloriesexpended.Adipose,glycogen,andmusclecanbeusedforenergytomakeupthecaloricdeficiency.能量代谢率也称代谢率（metabolicrate,MR)是指机体单位时间内消耗的能量。7.1.2.1能量代谢的测定原理测热量的产生（机体不做功）测能量的产生7.1.2Measuringthemetabolicrate7.1.2Measuringthemetabolicrate7.1.2.2与能量代谢有关的几个概念食物的热价(thermalequivalentoffood)：1g食物分解氧化时所释放的热量。有物理热价与生理热价，糖与脂肪的物理热价与生理热价相同，蛋白质不同。食物的氧热价(thermalequivalentofoxygen)：某种食物分解时每消耗1L氧所释放的热量。如果能够知道用于氧化分解某种食物的所消耗的氧量，乘以该物质的氧热价即可得……呼吸商(respiratoryquotient)与非蛋白呼吸商：一定时间内机体的CO2生成量与耗O2量的比值，称为呼吸商。糖的呼吸商为1，蛋白质约为0.8，脂肪约为0.71。人和动物的呼吸商在0.71-1之间变动。蛋白质的消耗量可用测定尿氮的方法求得，在总CO2产量与总O2消耗量中减去蛋白质的部分，就是非蛋白呼吸商。由非蛋白呼吸商可知氧化的糖与脂肪的比例。7.1.2.3能量代谢的测定方法测定方法分可分为两类：直接测热法和间接测热法。直...