Which test tube represents the control? The one with water. C. Why? When protein molecules are present, Beirut Reagent reacts with the protein to form a purple color. Tube number one is the control tube because it is distilled water and has no protein; the tube has no color. C. Which test tube contained the most test substance? Amylase D. Other than the control, which test tube contained the least test substance? Hard to say because the other ones didn’t have much of a color, so it didn’t seem like there was much protein at all. E. Did the results agree with your initial hypothesis in every case? Yes F. Why or why to?
Starches and sugars are helped by protein enzymes and Amylase is an enzyme. Good source of protein, so I thought Albumen would have protein Eggs are a foods, but the Beirut reagent isn’t strong enough to pick up small amounts G. If the color change is not as you expected, what might be the reasons? Contamination H. Add another 5 drops of Beirut Reagent to each test tube and stir as before. Do your results change? I didn’t notice any change Discussion A. What is the purpose of this exercise? To use color to detect if substances have protein since Beirut reagent would react with a protein to form a purple color B.
Why is it important to clean droppers and equipment between chemical uses? To avoid cross contamination C. What other types of foods or substances contain high levels of protein? Meat or fingernails D. Suggest a situation where you might use the Beirut Reagent colorimetric test. It kidney disease E. What other types of analytical procedures detect the presence of proteins? The Lowry Method Exercise 2: Testing for the Presence of Starch in Cells A. What is the test substance? Starch B. Which test tube represents the control? Water C. Why? Water has no starch and it turned amber, so if your color was amber, you ad no starch D.
Which test tube contained the most test substance? Potato starch Other than the control, which test tube contained the least test substance? Albumen and amylase E. Did the results agree with your initial hypothesis in each case, why or why not? Known to have starch, and they did. I didn’t expect the proteins Yes, potatoes are to have starch sources, but they’re not in every natural food source G. If the color change is not as you expected it to be, what might be the reasons? That items I did not think had starch, actually did have it. A. What is the purpose of this exercise?
Iodine reacts with carbohydrates to form a dark blue color, so you would know if the substance had carbohydrates based on the color it turned. B. What other types of foods or substances contain high levels of starch? Wheat grain C. Suggest a situation where you might use the iodine colorimetric test. Testing for thyroid issues D. What other types of analytical procedures detect the presence of starch? Detect the presence of starch by using the chemical method A. What is the test substance? Sugar C. Why? There is no sugar in water, and it turned a light blue.
Any test with that color old mean that there was no sugar C. Which test tube contained the most test substance? Glucose D. Besides the control, which test tube contained the least test substance? Potato starch D. Did the results agree with your initial hypothesis in every case? Yes E. Why or why not? The test specifically looks for glucose, so other carbohydrates and starches that don’t have glucose, will not show sugar F. What are you conclusions about the results? Glucose will react with Benedicts reagent G. If the color change is not as expected, what might be the reasons? Contamination
