1. Mark three clean test tubes as tubes 1, 2, 3, and prepare the tubes as follows:
Tube 1: Add 6 mL of amylase solution.
Tube 2: Add 6 mL of starch solution.
Tube 3: Add 5 mL of starch solution and 1 mL of amylase solution.
2. Shake the tubes well to mix the contents and place them in a warm water bath (37°C/98.6°F) for
3. At the end of the 10 minutes, test the contents of each tube for the presence of starch. To do this, follow these steps:
a. Place 1 mL of the solution to be tested in a depression of a porcelain test plate.
b. Next add two drops of iodine-potassium-iodide solution and note the color of the mixture. If the solution becomes blue-black, starch is present.
c. Record the results in Part A of Laboratory Report 51.
4. Test the contents of each tube for the presence of sugar (disaccharides in this instance). To do this, follow these steps:
a. Place 1 mL of the solution to be tested in a clean test tube.
b. Add 1 mL of Benedict's solution.
c. Place the test tube with a test-tube clamp in a beaker of boiling water for 2 minutes.
d. Note the color of the liquid. If the solution becomes green, yellow, orange, or red, sugar is present. Blue indicates a negative test, whereas green indicates a positive test with the least amount of sugar, and red indicates the greatest amount of sugar present.
e. Record the results in Part A of the laboratory report.
3. Add 5 mL of starch solution to each tube, shake to mix the contents, and return the tubes to their respective test temperatures for 10 minutes. It is important that the 5 mL of starch solution added to tube 4 be at ice-water temperature before it is added to the 1 mL of amylase solution.
4. At the end of the 10 minutes, test the contents of each tube for the presence of starch and the presence of sugar by following the directions in Procedure A.
5. Complete Part B of the laboratory report.
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This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.