Podcast
Questions and Answers
在测试绿叶中的淀粉时，首先需要对叶子进行什么处理？
在测试绿叶中的淀粉时，首先需要对叶子进行什么处理？
使用乙醇处理叶子时，为什么选择在通风良好的地方进行？
使用乙醇处理叶子时，为什么选择在通风良好的地方进行？
为什么在用碘溶液测试淀粉之前需要用酒精溶解叶子的叶绿素？
为什么在用碘溶液测试淀粉之前需要用酒精溶解叶子的叶绿素？
将叶子放入热水中的目的是什么？
将叶子放入热水中的目的是什么？
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在测试淀粉的过程中，颜色变化需要记录。此时记录哪个颜色的变化是正确的？
在测试淀粉的过程中，颜色变化需要记录。此时记录哪个颜色的变化是正确的？
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在进行实验的时候，为什么使用绝对小的乙醇量？
在进行实验的时候，为什么使用绝对小的乙醇量？
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使用夹持器或玻璃棒转移叶子时，主要目的是为了？
使用夹持器或玻璃棒转移叶子时，主要目的是为了？
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在观察到的叶子颜色的变化中，下列哪一项不是安全相关的警告？
在观察到的叶子颜色的变化中，下列哪一项不是安全相关的警告？
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Study Notes
Testing for Starch in a Green Leaf
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Procedure:
- Gather a potted plant that has been exposed to sunlight for several hours.
- Obtain a green leaf from the plant.
- Boil the leaf in water for 10 minutes to destroy cell membranes, allowing iodine solution access.
- Use a Bunsen burner or hot plate to boil the leaf. Alternatively, a hot plate could be used.
- Turn off the Bunsen burner to prevent burns.
- Place the beaker containing the boiled leaf onto an insulating mat.
- Fill a boiling tube with alcohol approximately one-third full.
- Use forceps or a glass rod to carefully place the leaf in the boiling tube.
- Submerge the boiling tube in a beaker of hot water for 10 minutes to remove chlorophyll. This is important to not mask the color changes in the leaf.
- Remove the boiling tube from the hot water.
- Transfer the leaf to hot water again. This removes any remaining alcohol and softens the leaf.
- Use forceps to take the leaf out of the hot water and spread it on a white tile.
- Record the color of the leaf.
- Add 10 drops of iodine solution to the leaf to test for starch. Record any color changes.
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Safety Precautions:
- Wear safety spectacles to protect your eyes.
- Be cautious with hot equipment and water.
- Be careful when using alcohol; since alcohol is flammable, use the smallest volume possible and ensure the room is well ventilated. Do not use alcohol near flames.
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Description
该测验涵盖了如何测试绿色叶子中的淀粉含量。通过详细的实验步骤，您将学习如何处理叶子，并使用碘液检测淀粉的存在。掌握这些步骤将帮助您理解植物光合作用和淀粉合成的基本概念。
