未被消化蛋白质.ppt

According to the pH in intestine pH NH3 + H+ NH 4+ excrete ? pH absorpted to venous blood c. Regulation of urea synthesis food enzymes (AGA) intermediates biological significant of urea synthesis Synthesis of non essential A.A or other nitrogen compounds muscle or other tissues Gln muscle urea NH3 Ala liver 4. Metabolism of ?-keto acids Amino acid NH3 Ala Gln urea Amination of a-keto acids Amination or transamination To form non E.A.A. Conversion of fat,glucose Via TCA cycle oxidized to CO2 H2O ?-keto acids 1) Amination or transamination To form non E.A.A. α- ketoglutarate Glu Pyruvate Ala oxaloacetate Asp Glu α- ketoglutarate oxaloacetate Asp TCA cycle Conversion to lipids or carbohydrates glycogenic amino acid, such as : Ala、Arg、Asp etc（13 ） ketogenic amino acid such as: leu lys (2) glycogenic ketogenic amino acids such as : Ilu,Phe,Trp,Tye TCA cycle is the hinge of metabolism of lipids , carbohydrates, proteins * * * * * * * * 3) oxidation provide energy 3. decarboxylation ? glucose-alanine cycle process biological significance Putrefaction in small intestine Intestine-liver cycle of urea Absorption In small intestine （oxidation of amines） 　deamination of A.A Ammonia in blood Ala in liver GLn c. the fates of ammonia Synthesis of non essential A.A or other nitrogen compounds muscle or other tissues Gln muscle urea NH3 Ala liver synthesis of urea---main outlet of ammonia a. site b. process (ornithine cycle ) *肝脏是合成尿素最主要的器官 血 尿 切肝犬 尿素 氨 尿素 用氨基酸饲养切肝犬 尿素 氨基酸 尿素 切肾犬 急性黄色肝委缩 氨基酸 尿素 （-） 氨 尿素 （-） Th