“唾液淀粉酶对淀粉的消化作用”的实验,教科书上要求的实验步骤是:分别在二个试管中加入2毫升制好的淀粉液;在一号试管中加入2毫升清水,在二号试管中加入2毫升唾液;然后将它们放入37℃左右的温水中,约过10分钟,在二只试管中分别加入2滴碘酒,观察颜色的变化。但是,我看到一些参考书的习题中,对这个实验步骤作了一点改动:在二只装好淀粉液的试管中,在一号试管中加入2毫升清水,在二号试管中加入2毫升唾液,再分别加入2滴碘酒,放入37℃左右的温水中。过10分钟观察颜色的变化。得出的结论是:一号试管不退色,二号试管退色。以上两个实验步骤看起来似乎是一样的,只是前者将二只试管放入37℃左右温水中10分钟后加入碘酒, “Digestive effects of salivary amylase on starch” experiments, textbooks required experimental steps are: adding two milliliters of well-prepared starch solution in two test tubes; in the first test tube by adding 2 ml of water, in the second test tube Add 2 ml of saliva; then place them in warm water at about 37 ° C for about 10 minutes. Add two drops of iodine in two test tubes to observe the color change. However, I saw a few reference book exercises that made a slight change to this experimental procedure: Add two milliliters of clear water to one test tube and two milliliters Saliva, then add two drops of iodine, respectively, into about 37 ℃ warm water. After 10 minutes to observe the color changes. The conclusion is: one tube does not fade, tube II fade. The above two experimental steps seem to be the same, but the former will be two test tubes into about 37 ℃ warm water after 10 minutes add iodine,