Combined Guided and Open Inquiry Project for an Upper Division Biochemistry Lab: Sugar Content, Enzymatic Properties of Lactase, and the Spoiling Process in Milk
Combined Guided and Open Inquiry Project for an Upper Division Biochemistry Lab: Sugar Content, Enzymatic Properties of Lactase, and the Spoiling Process in Milk
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DOI：
10.1021/acs.jchemed.9b00926
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发表时间：
2020-05-12
影响因子：
3
通讯作者：
Willian, Kyle R.
中科院分区：
文献类型：
--
作者：
Redden, Alexis M. Vroom;Barton, Callie M.;Willian, Kyle R.
引导式询问是一种允许学生对一组数据得出自己的结论的做法，而不是使用给定的实验程序来验证已知结果。开放探究使这一理念更上一层楼，允许学生发展自己的实验，然后分析数据得出结论。为了让高年级本科生了解实验发展的概念和研究的思维过程，我们开发了一套安全但发人深省的相关实验，将引导式探究和开放式探究教学方法相结合。在两个指导性的探究性实验中，学生们使用可检测所有还原糖的DNS试剂(二硝基水杨酸)和葡萄糖氧化酶-过氧化物酶测定法对新鲜牛奶、变质牛奶和经乳糖酶处理的牛奶中的糖的数量和类型进行了量化。这导致了开放式探究性实验，学生们提出了他们自己的假设，并测试了乳糖酶的化学、牛奶变质的化学以及其他确定牛奶中糖含量的方法的各个方面。介绍了一些比较常见的学生衍生实验，例如在DNS检测中使用不同的糖标准，以及在不同温度和pH下测试乳糖酶的活性。
Guided inquiry is the practice of allowing students to come to their own conclusions about a set of data instead of verifying a known result using a given experimental procedure. Open inquiry takes this idea one step further by allowing students to develop their own experiment and then analyze the data to arrive at a conclusion. To expose upper level undergraduate students to the concepts of experimental development and the research thought process, a safe but thought provoking and relevant set of experiments was developed, combining guided inquiry and open inquiry teaching methods. Two guided inquiry experiments have the students quantify the amount and types of sugars present in fresh milk, spoiling milk, and lactase-treated milk using DNS reagent (dinitrosalicylic acid) which detects all reducing sugars and a glucose oxidase-peroxidase assay to determine glucose only. This leads into open inquiry experiments where the students develop their own hypothesis and test various aspects of the chemistry of the lactase enzyme, the chemistry of milk spoilage, and other means to determine the content of sugars in milk. Some of the more common student derived experiments are presented such as using different sugar standards in the DNS assay and testing the activity of lactase at different temperatures and pH.