碳水化合物的消化CHOdig课件

1、碳水化合物的消化CHOdig1Large IntestineCarbohydrate Digestion in RuminantSmall IntestinePancreasRumen-Reticulum碳水化合物的消化CHOdig2FermentationMammalian digestionStarchSalivary AmylaseStarch + large dextrinsMaltotriose and alpha limit dextrinsMaltoseMaltasePancreatic amylaseGlucose+LactoseSucroseLactaseSucraseGlu

2、coseFructoseGalactoseFIBERFiberUndigested starch and dextrinsVolatile fatty acids非反刍动物的碳非反刍动物的碳水化合物消化水化合物消化乳糖乳糖蔗糖蔗糖纤维纤维淀粉淀粉碳水化合物的消化CHOdig3Large IntestineCarbohydrate Digestion in RuminantSmall IntestinePancreasRumen-ReticulumStarchAcetic acid Propionic acidButyric acidEnergy, Synthesis of Fatty acid

3、Energy,Synthesis of GlucoseEnergyCelluloseHemicellulosePectinLignin GlucoseFermentationMammalian digestionFermentationFermentation碳水化合物的消化CHOdig4What are the primary molecules pigs use for energy when fed a grain based diet VFA Glucose碳水化合物的消化CHOdig5What are the primary molecules cattle, sheep and g

4、oats use for energy when fed a high grain diet VFA Glucose碳水化合物的消化CHOdig6What are the primary molecules cattle, sheep and goats use for energy when fed a all forage diet VFA Glucose碳水化合物的消化CHOdig7What are the primary molecules horses use for energy when fed a all forage diet VFA Glucose碳水化合物的消化CHOdi

5、g8What are the primary molecules horses use for energy when fed a diet consisting of 50% grain and 50% forage? VFA Glucose碳水化合物的消化CHOdig9Sites of Carbohydrate Digestion碳水化合物消化位置碳水化合物消化位置MouthMouthlSalivary amylase begins Salivary amylase begins digestion of starchdigestion of starchl唾液淀粉酶开始淀粉消化唾液淀粉酶

6、开始淀粉消化TrueTrue StomachStomachlHCl ruptures starch HCl ruptures starch granulesgranules胃酸破裂淀粉细粒胃酸破裂淀粉细粒碳水化合物的消化CHOdig10Sites of Carbohydrate Digestion碳水化合物消化位置碳水化合物消化位置Small IntestineSmall Intestine小肠小肠lAmylaseAmylase淀粉酶淀粉酶From the pancreas; primary enzyme digesting starch胰腺分泌淀粉酶，是基本的淀粉消化酶。lMaltaseMa

7、ltase麦芽糖酶麦芽糖酶(brush border enzyme)刷状缘酶lSucraseSucrase甘蔗糖甘蔗糖(brush border enzyme)刷状缘酶(not found in ruminants)反刍动物未发现甘蔗糖酶lLactaseLactase乳糖酶乳糖酶(brush border enzyme)刷状缘酶碳水化合物的消化CHOdig11Carbohydrate Digestion By Mammalian Enzymes哺乳动物碳水化合物消化酶哺乳动物碳水化合物消化酶Substrate物质物质Enzyme酶酶Product产物产物Starch淀粉淀粉Amylase淀粉酶

8、淀粉酶Dextrins糊精糊精Dextrins糊精糊精Amylase淀粉酶淀粉酶 maltose + maltotriose + -limit dextrins麦芽糖麦芽糖+麦芽三糖麦芽三糖+ -有限糊精有限糊精Maltose麦芽糖麦芽糖Maltase淀淀粉酶粉酶glucose + glucose葡萄糖葡萄糖+葡萄糖葡萄糖Lactose乳糖乳糖Lactase乳乳糖酶糖酶glucose + galactose葡萄糖葡萄糖+半乳糖半乳糖Sucrose蔗糖蔗糖Sucrase蔗蔗糖酶糖酶glucose + fructose葡萄糖葡萄糖+果糖果糖碳水化合物的消化CHOdig12Sites of Carb

9、ohydrate Digestion碳水化合物消化位置碳水化合物消化位置Rumen-Reticulum/Large Intestine瘤胃瘤胃-网胃网胃/大肠大肠lBacteria and protozoa ferment carbohydrates and produce the VFAl细胞和原虫发酵碳水化合物生成挥发性脂肪酸细胞和原虫发酵碳水化合物生成挥发性脂肪酸For Example: Substrate物质物质Enzyme酶酶Product产物产物Cellulose纤维素纤维素Cellulase纤维素酶纤维素酶 cellobiose (2 glucose linked by 1-4

10、bonds)纤维二糖纤维二糖Cellobiose纤维二糖纤维二糖Cellulase纤维素酶纤维素酶 Glucose葡萄糖葡萄糖Glucose葡萄糖葡萄糖lots VFA 挥发性脂肪酸挥发性脂肪酸碳水化合物的消化CHOdig13Absorption of Monosaccharides单糖吸收单糖吸收Absorbed only in the small intestine 单糖只在小肠吸收单糖只在小肠吸收Absorption requires carrier molecules and energy, so it is termed active transport 单糖吸收需要载体和能量，所以

11、属于主动转运。单糖吸收需要载体和能量，所以属于主动转运。碳水化合物的消化CHOdig14Volatile Fatty Acid Formation from Glucose葡萄糖形成挥发性脂肪酸葡萄糖形成挥发性脂肪酸Acetic acidGlucoseC6H12O62 acetate + CO2 + CH4 + Heat(2) C2H4O2Propionic acidGlucose + electrons2 propionate + H2O(2) C3H6O2Butyrate + CO2 + CH4Butyric acidC6H12O6C6H12O6C4H8O2Glucose乙酸乙酸丙酸丙酸丁

12、酸丁酸葡萄糖葡萄糖碳水化合物的消化CHOdig15Efficiencies of Volatile Fatty Acid Formation*挥发性脂肪酸合成效率挥发性脂肪酸合成效率碳水化合物的消化CHOdig16Acetate乙酸乙酸Absorbed and carried to the liver, but a small amount is converted to ketone bodies in the rumen wall 吸收转运至肝脏，但小量在瘤胃壁内转化成酮体吸收转运至肝脏，但小量在瘤胃壁内转化成酮体In the liver acetate is converted to a

13、cetyl CoA which can be:在肝，乙酸被转化成乙酰辅酶在肝，乙酸被转化成乙酰辅酶AlOxidized via the TCA cycle to produce energy 通过三羧酸循环氧化产生能量通过三羧酸循环氧化产生能量lUsed to synthesize fatty acids用于合成脂肪酸用于合成脂肪酸Precursor of milk and body fatty acids; inadequate production of acetate by fermentation in lactating dairy cows will lower butter fa

14、t content乳和体内脂肪酸的前体，泌乳牛通过发乳和体内脂肪酸的前体，泌乳牛通过发酵产生的乙酸量不足时，体脂含量会降低。酵产生的乙酸量不足时，体脂含量会降低。碳水化合物的消化CHOdig17Propionate丙酸丙酸Absorbed and carried to liver吸收转运至肝吸收转运至肝Converted to Succinyl CoA转化成辅酶转化成辅酶ASuccinyl CoA can be used in TCA cycle to produce energy or it can be used for synthesis of glucose 辅酶辅酶A被用于三羧酸循环

15、而产生能量，或者用于合成葡萄糖。被用于三羧酸循环而产生能量，或者用于合成葡萄糖。Propionic acid is the main precursor for glucose synthesis in ruminants 反刍动物中，丙酸是合成葡萄糖的主要前体。反刍动物中，丙酸是合成葡萄糖的主要前体。碳水化合物的消化CHOdig18Butyrate丁酸丁酸Almost all is converted to 3-hydroxybutyrate (a ketone body) in rumen wall and used for energy production在瘤胃壁内转化成在瘤胃壁内转化

16、成3-羟基丁酸（一种酮体），用于产生能量。羟基丁酸（一种酮体），用于产生能量。碳水化合物的消化CHOdig19Importance of VFAs for Ruminants挥发性脂肪酸对反刍动物的重要性挥发性脂肪酸对反刍动物的重要性Primary molecules used for energy at the tissue level 在组织水平是合成能量的基本分子在组织水平是合成能量的基本分子Acetate is the most abundant VFA produced by fermentation; propionate = 2nd; butyrate = 3rd 乙酸是通过发酵

17、产生的最多挥发性脂肪酸，是丙酸二倍，丁酸三倍。乙酸是通过发酵产生的最多挥发性脂肪酸，是丙酸二倍，丁酸三倍。Exact ratios of acetate:propionate:butyrate vary with diet and feeding practices, but the ranking never changes 乙酸乙酸:丙酸丙酸:丁酸的比例会随饲粮和饲养水平而变化，但排序不会变。丁酸的比例会随饲粮和饲养水平而变化，但排序不会变。碳水化合物的消化CHOdig20Effect of Forage:Concentrate Ratio on Proportion of Fatty A

18、cids in the Rumen粗精比对瘤胃中脂肪酸含量的影响粗精比对瘤胃中脂肪酸含量的影响Molar Ratio摩尔比摩尔比Forage:Concentrate粗精比粗精比Acetate乙酸乙酸Propionate丙酸丙酸Butyrate丁酸丁酸100:071.416.07.975:2568.218.18.050:5065.318.410.440:6059.825.910.220:8053.630.610.7碳水化合物的消化CHOdig21Importance of VFAs for Ruminants挥发性脂肪酸对反刍动物的重要性挥发性脂肪酸对反刍动物的重要性Feeding high s

19、tarch diets (high in grain) increases the proportion of propionate and increases growth rate, feed efficiency and milk production compared to feeding high fiber diets. 与饲喂高纤维饲粮相比，饲喂高淀粉饲粮（谷物含量高）提与饲喂高纤维饲粮相比，饲喂高淀粉饲粮（谷物含量高）提高丙酸的比例，进而提高生长速度、饲料转化率和奶产量。高丙酸的比例，进而提高生长速度、饲料转化率和奶产量。Feeding high fiber diets (hi

20、gh in roughages) increases the proportion of acetate and increases fat content of milk in cows. Growth rate, feed efficiency and milk production will be lower, compared to high grain diets. 与饲喂高谷物饲粮相比，饲喂高纤维饲粮（粗饲料含量高）与饲喂高谷物饲粮相比，饲喂高纤维饲粮（粗饲料含量高）提高乙酸的比例，进而增加奶牛中乳脂含量。但生长速度、提高乙酸的比例，进而增加奶牛中乳脂含量。但生长速度、饲料转化率和奶产量将下降。饲料转化率和奶产量将下降。碳水化合物的消化CHOdig22Importance of VFAs for Ruminants挥发性脂肪酸对反刍动物的重要性挥发性脂肪酸对反刍动物的重要性Grinding, pelleting, and some additives (e.g., monesin) increase production of propionate by altering the microbial population in the rumen 粉碎、制粒和一些