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1、酶的特性,酶 本 质 的 探 索,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,【学习目标】 1、能说出酶的本质是什么？ 2、科学家是怎样研究酶的本质的？ 3、举例说明酶的特性。
2、 4举例说出酶需温和的条件 5 探究温度对淀粉酶活性的影响,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,李比希,巴斯德,发酵是纯化学反应,与生命活动无关,发酵与活细胞有关,发酵
3、 是整个细胞而不是细胞 中的某些物质在起作用,引起发酵的是细胞中的某些物 质,但这些物质只有在酵母细胞 死亡裂解释放后才能发挥作用.,酵母细胞中的某些物质能够在酵母细胞破 碎后继续起作用,就像在活细胞中一样.,酶是蛋白质,少数酶是RNA,毕希纳,巴斯德之前,萨姆纳,切赫,奥特曼,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides
4、 for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,酶是活细胞产生的具有催化作用的有机物,酶的本质,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copy
5、right 2004-2011 Aspose Pty Ltd.,1、酶的基本组成单位是（ ） A.氨基酸 B.核苷酸 C.核糖核苷酸 D.A或C 2、酶是（ ）产生的具有催化作用的 （ ），其中绝大多数酶是（ ） 少数是 （ ）,练习反馈,D,活细胞,有机物,蛋白质,RNA,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides f
6、or .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,酶的特性,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspos
7、e Pty Ltd.,酶对化学反应的催化效率称为酶活性,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,由此你能得出酶具有什么特性?,大量实验数据表明：酶的催化效率是无机催化剂的1
8、071013倍,资料： 1份的淀粉酶能催化100万份的淀粉成麦芽糖,(一)、酶具有高效性,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,资料： 1、研究发现淀粉酶只能催化淀粉分解
9、成 麦芽糖，而不能分解别的物质。 2、二肽酶能将二肽分解成氨基酸,确切说:每一种酶只能催化一种或一类化学反应,(二)、酶具有专一 性,细胞代谢能够有条不紊地进行，与酶的 是分不开的。,目前发现的酶有 多种,它们分别催化不同 的化学反应。,专一性,4000,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.
10、5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,酶A与底物B专一性结合，催化反应的发生，产生了产物C和D。这个模型揭示了酶的专一性。,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.
11、0. Copyright 2004-2011 Aspose Pty Ltd.,酶需适宜的条件,酶需适宜的温度 酶需适宜的PH值,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,【二
12、】探究温度对淀粉酶活性的影响,(1)自变量：,温度,（已知淀粉酶的适用温度范围是5075）,(2)因变量：,(3)无关变量：,不同温度条件下淀粉酶的活性,实验操作顺序、溶液的量、时间、温度是否达到预设的温度等,（0 、60 、100 ）,如何检测？,2.实验用品：,质量分数为3的可溶性淀粉溶液、质量分数为 2的淀粉酶溶液、冰水（0）、热水、碘液,(4)实验原则：,单一变量原则、等量原则、对照实验原则,1.实验分析,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright
13、2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,探究温度对淀粉酶活性的影响,3.具体操作步骤,加入淀粉酶溶液,保温5分钟,加入淀粉溶液,1,2,3,1mL,1mL,1mL,0 ,60,100,2mL,2mL,2mL,1滴,1滴,1滴,滴入碘液,观察颜色变化,1,2,3,0 ,60,100,将对应编号的 溶液混合,将1试管淀粉溶液倒入1号管，2试管的倒入 2号管
14、，3试管的倒入3号管，振荡摇匀,0 ,60,100,/,/,/,/,/,/,/,/,/,/,/,/,保温1分钟,4.进行实验,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,1滴,
15、1滴,1滴,滴入碘液,观察颜色变化,变蓝,不变蓝,变蓝,0 ,60,100,保温,5.分析实验结果，得出结论,温度会影响酶的活性,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,6
16、.拓展,试管1的现象说明：0下酶仍有活性，只是活性很低，随着温度升高，这时酶活性增强；,1滴,1滴,1滴,滴入碘液,观察颜色变化,变蓝,不变蓝,变蓝,0 ,60,100,保温,变温处理2分钟,60,60,/,观察颜色变化,蓝色消退,蓝色不变,/,试管3的现象说明：100 下酶已经失去活性，并且酶的这种失活是不可恢复的。,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.,在最适温度条件下，酶的活性最高；高于或低于最适温度，酶活性都会明显降低；温度过高时会导致酶失去活性。,酶活性受温度的影响,Evaluation o
