Testing for Macromolecules

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TESTING FOR MACROMOLECULES

Describe the positive test for starch. Explain how you know. The positive test for starch is adding iodine solution. In the experiment, the starch solution had the most dramatic reaction with the iodine solution. It turned to an opaque bluish-purple solution while other samples all turned to a colour related to orange and yellow other than the vegetable oil. But the vegetable oil was more translucent than completely opaque.

Describe the positive test for glucose. Explain how you know. The positive test for glucose is be adding Benedict’s solution. In the experiment, the glucose solution had the most dramatic reaction with the Benedict’s solution after it got heated. It turned to an opaque yellowish orange solution with dark-orange precipitate at the bottom while other samples all turned to a colour related to blue, other than the unknown solution.

Describe the positive test for lipid. Explain how you know. The positive test for lipid is the Sudan IV solution. I know this because it is the only substance who turned shiny afterwards. All of the other ones were matte.

Describe the positive test for protein. Explain how you know. The positive test for protein is adding the Biuret solution. I know this because the protein is the substance who had the most dramatic reaction with the Biuret Solution. While all of the other substances turned blue and yellow, the protein turned purple.

What substances were present in the unknown solution? Explain how you know. The glucose solutions and starch solutions are the ones included in the unknown solution. I know this because they have the same positive tests.

What was the the purpose of testing distilled water for each part of the investigation. The purpose of testing distilled water for each part of the investigation was to show the most natural reaction and colour change with the indicators without any other chemicals affecting the results since...
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