问题 实验题

利用纤维素解决能源问题的关键,是高性能纤维素酶的获取。请完善实验方案,并回答相关问题。实验目的:比较三种微生物所产生的纤维素酶的活性。

实验原理:纤维素酶催化纤维素分解为葡萄糖,用葡萄糖的产生速率表示酶活性大小;用呈色反应表示葡萄糖的生成量。

实验材料:三种微生物(A~C)培养物的纤维素酶提取液,提取液中酶蛋白浓度相同。

实验步骤:

(1)取四支试管,分别编号。

(2)在下表4列中每列的一个适当位置,填写相应试剂的体积量,并按表内要求完成相关操作。

(3)将上述四支试管放入37℃的水浴,保温1小时。

(4)在上述四支试管中分别加入等量______试剂,摇匀后,进行_______处理。

(5)观察比较实验组的三支试管与对照组试管的颜色深浅。

实验结果:

分析讨论:

(6)该实验中的对照组是_______号试管。

(7)实验组试管均呈现的颜色是________,但深浅不同。

(8)上述结果表明:不同来源的纤维素酶,虽然酶蛋白浓度相同,但活性不同。若不考虑酶的最适pH和最适温度的差异,从氨基酸层次上分析其可能原因是不同酶本身的________。

(9)你认为上述三种微生物中,最具有应用开发价值的是微生物________。某科研小组从该微生物中得到高性能纤维素酶后,在最适温度、最适pH值的条件下,对该酶的催化反应过程进行研究,得到产物浓度随时间的变化曲线图。

请根据以上实验结果,回答下列问题:

①.当一开始时,将混合物中纤维素酶的浓度增加50%,在上图画出反应过程中产物浓度随时间变化的曲线(请用“1”标注)。

②.当一开始时,将混合物中纤维素酶的反应温度降低10℃,请在上图中画出理想条件下产物浓度随时间变化的曲线(用“2”标注温度降低后的变化曲线)。

答案

(2)

(4)斐林试剂    水浴加热

(6)4

(7)砖红色

(8)氨基酸种类、数目、排列顺序不同

(9)B

完形填空
完形填空。
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单项选择题