齊魯醫(yī)學碳水化合物的消化CHO-dig

1、2021/9/301Large IntestineCarbohydrate Digestion in RuminantSmall IntestinePancreasRumen-Reticulum2021/9/302FermentationMammalian digestionStarchSalivary AmylaseStarch + large dextrinsMaltotriose and alpha limit dextrinsMaltoseMaltasePancreatic amylaseGlucose+LactoseSucroseLactaseSucraseGlucoseFructo

2、seGalactoseFIBERFiberUndigested starch and dextrinsVolatile fatty acids非反芻動物的碳水化合物消化乳糖蔗糖纖維淀粉2021/9/303Large IntestineCarbohydrate Digestion in RuminantSmall IntestinePancreasRumen-ReticulumStarchAcetic acid Propionic acidButyric acidEnergy, Synthesis of Fatty acidEnergy,Synthesis of GlucoseEnergyCel

3、luloseHemicellulosePectinLignin GlucoseFermentationMammalian digestionFermentationFermentation2021/9/304What are the primary molecules pigs use for energy when fed a grain based dietVFAGlucose2021/9/305What are the primary molecules cattle, sheep and goats use for energy when fed a high grain dietVF

4、AGlucose2021/9/306What are the primary molecules cattle, sheep and goats use for energy when fed a all forage dietVFAGlucose2021/9/307What are the primary molecules horses use for energy when fed a all forage dietVFAGlucose2021/9/308What are the primary molecules horses use for energy when fed a die

5、t consisting of 50% grain and 50% forage?VFAGlucose2021/9/309Sites of Carbohydrate Digestion碳水化合物消化位置MouthSalivary amylase begins digestion of starch唾液淀粉酶開始淀粉消化True StomachHCl ruptures starch granules胃酸破裂淀粉細粒2021/9/3010Sites of Carbohydrate Digestion碳水化合物消化位置Small Intestine小腸Amylase淀粉酶From the pancr

6、eas; primary enzyme digesting starch胰腺分泌淀粉酶，是基本的淀粉消化酶。Maltase麥芽糖酶(brush border enzyme)刷狀緣酶Sucrase甘蔗糖(brush border enzyme)刷狀緣酶(not found in ruminants)反芻動物未發(fā)現(xiàn)甘蔗糖酶Lactase乳糖酶(brush border enzyme)刷狀緣酶2021/9/3011Carbohydrate Digestion By Mammalian Enzymes哺乳動物碳水化合物消化酶Substrate物質(zhì)Enzyme酶Product產(chǎn)物Starch淀粉Amyl

7、ase淀粉酶Dextrins糊精Dextrins糊精Amylase淀粉酶 maltose + maltotriose + -limit dextrins麥芽糖+麥芽三糖+-有限糊精Maltose麥芽糖Maltase淀粉酶glucose + glucose葡萄糖+葡萄糖Lactose乳糖Lactase乳糖酶glucose + galactose葡萄糖+半乳糖Sucrose蔗糖Sucrase蔗糖酶glucose + fructose葡萄糖+果糖2021/9/3012Sites of Carbohydrate Digestion碳水化合物消化位置Rumen-Reticulum/Large Intes

8、tine瘤胃-網(wǎng)胃/大腸Bacteria and protozoa ferment carbohydrates and produce the VFA細胞和原蟲發(fā)酵碳水化合物生成揮發(fā)性脂肪酸For Example: Substrate物質(zhì)Enzyme酶Product產(chǎn)物Cellulose纖維素Cellulase纖維素酶 cellobiose (2 glucose linked by 1-4 bonds)纖維二糖Cellobiose纖維二糖Cellulase纖維素酶 Glucose葡萄糖Glucose葡萄糖lots VFA 揮發(fā)性脂肪酸2021/9/3013Absorption of Monos

9、accharides單糖吸收Absorbed only in the small intestine 單糖只在小腸吸收Absorption requires carrier molecules and energy, so it is termed active transport 單糖吸收需要載體和能量，所以屬于主動轉(zhuǎn)運。2021/9/3014Volatile Fatty Acid Formation from Glucose葡萄糖形成揮發(fā)性脂肪酸Acetic acidGlucoseC6H12O62 acetate + CO2 + CH4 + Heat(2) C2H4O2Propionic

10、acidGlucose + electrons2 propionate + H2O(2) C3H6O2Butyrate + CO2 + CH4Butyric acidC6H12O6C6H12O6C4H8O2Glucose乙酸丙酸丁酸葡萄糖2021/9/3015Efficiencies of Volatile Fatty Acid Formation*揮發(fā)性脂肪酸合成效率2021/9/3016Acetate乙酸Absorbed and carried to the liver, but a small amount is converted to ketone bodies in the rum

11、en wall 吸收轉(zhuǎn)運至肝臟，但小量在瘤胃壁內(nèi)轉(zhuǎn)化成酮體In the liver acetate is converted to acetyl CoA which can be:在肝，乙酸被轉(zhuǎn)化成乙酰輔酶AOxidized via the TCA cycle to produce energy 通過三羧酸循環(huán)氧化產(chǎn)生能量Used to synthesize fatty acids用于合成脂肪酸Precursor of milk and body fatty acids; inadequate production of acetate by fermentation in lactating

12、 dairy cows will lower butter fat content乳和體內(nèi)脂肪酸的前體，泌乳牛通過發(fā)酵產(chǎn)生的乙酸量不足時，體脂含量會降低。2021/9/3017Propionate丙酸Absorbed and carried to liver吸收轉(zhuǎn)運至肝Converted to Succinyl CoA轉(zhuǎn)化成輔酶ASuccinyl CoA can be used in TCA cycle to produce energy or it can be used for synthesis of glucose 輔酶A被用于三羧酸循環(huán)而產(chǎn)生能量，或者用于合成葡萄糖。Propioni

13、c acid is the main precursor for glucose synthesis in ruminants 反芻動物中，丙酸是合成葡萄糖的主要前體。2021/9/3018Butyrate丁酸Almost all is converted to 3-hydroxybutyrate (a ketone body) in rumen wall and used for energy production在瘤胃壁內(nèi)轉(zhuǎn)化成3-羥基丁酸（一種酮體），用于產(chǎn)生能量。2021/9/3019Importance of VFAs for Ruminants揮發(fā)性脂肪酸對反芻動物的重要性Prim

14、ary molecules used for energy at the tissue level 在組織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 乙酸是通過發(fā)酵產(chǎn)生的最多揮發(fā)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

15、酸:丙酸:丁酸的比例會隨飼糧和飼養(yǎng)水平而變化，但排序不會變。2021/9/3020Effect of Forage:Concentrate Ratio on Proportion of Fatty Acids in the Rumen粗精比對瘤胃中脂肪酸含量的影響Molar Ratio摩爾比Forage:Concentrate粗精比Acetate乙酸Propionate丙酸Butyrate丁酸100:071.416.07.975:2568.218.18.050:5065.318.410.440:6059.825.910.220:8053.630.610.72021/9/3021Importan

16、ce of VFAs for Ruminants揮發(fā)性脂肪酸對反芻動物的重要性Feeding high starch diets (high in grain) increases the proportion of propionate and increases growth rate, feed efficiency and milk production compared to feeding high fiber diets. 與飼喂高纖維飼糧相比，飼喂高淀粉飼糧（谷物含量高）提高丙酸的比例，進而提高生長速度、飼料轉(zhuǎn)化率和奶產(chǎn)量。Feeding high fiber diets (h

17、igh 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. 與飼喂高谷物飼糧相比，飼喂高纖維飼糧（粗飼料含量高）提高乙酸的比例，進而增加奶牛中乳脂含量。但生長速度、飼料轉(zhuǎn)化率和奶產(chǎn)量將下降。2021/9/3022Importance of VFAs for Ruminants揮

18、發(fā)性脂肪酸對反芻動物的重要性Grinding, pelleting, and some additives (e.g., monesin) increase production of propionate by altering the microbial population in the rumen 粉碎、制粒和一些飼料添加劑通過改變瘤胃中微生物數(shù)量提高丙酸產(chǎn)量2021/9/3023Importance of VFAs for Herbivores, Omnivores揮發(fā)性脂肪酸對草食性家畜的重要性In the cecum and colon, acetate is predominant product of fermentation followed by propionate and butyrate. 在盲腸和直腸，乙酸是由丙酸和丁酸發(fā)酵的前體物質(zhì)。The VFA are the primary molecul