[aminoacids中国医科大学生物化学课件氨基酸英文课件.ppt

Chapter 7 Amino Acid Metabolism The biochemistry and molecular biology department of CMU Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Section 1 Nutritional Function of Proteins Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1. Keep the cells and tissues growing, renewing and mending 2. Take part in some kinds of important physiological activities 3. Oxidation and supply energy § 1.1 The significance of proteins Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. § 1.2 The requirements and nutritious value of proteins 1. Nitrogen balance Measuring the amount of intake and losses of total nitrogen can help us to know the general situation of protein metabolism. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. There are three kinds of conditions: 1) Normal nitrogen balance intake N = losses N 2) Positive nitrogen balance intake N losses N 3) Negative nitrogen balance intake N losses N Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2. Physical requirements of proteins Lowest requirement: 30~50g/day Recommend requirement: 80g/day (65kg man) Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3. Nutrition value of proteins (1) Essential amino acids : Amino acids that cannot be synthesized by the body and must be obtained from the diet. Eight kinds of essential AAs: Val, Ile, Leu, Phe, Met, Trp, Thr, Lys Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. (2) Non- essential amino acids