You know that you can use different indicators to determine which macromolecules are in food items. You know that you can use iodine to look for starch, Sudan IV to look for lipids, Benedict's reagent to look for simple sugars, and biuret reagent to look for proteins. You collect samples of each area in the kitchen and take them back to the lab to be tested.
Area 1: White crystalline solid-dissolves in water, but solution does not conduct electricity
Since this sample came from a kitchen, you assume that it is safe to taste it and so you do to see if it is salty or sweet. It tastes sweet. You test it for all 4 macromolecules and you get the following results:
Iodine: brown
Sudan III: red
Benedict's: blue
Biuret: blue
After treating the sample with sucrase, you get these results:
Iodine: brown
Sudan III: red
Benedict's: orange
Biuret: blue
Area 2: Translucent, gelatinous semi-solid, slimy
You test it for all 4 macromolecules and you get the following results:
Iodine: brown
Sudan III: red
Benedict's: blue
Biuret: purple
Area 3: White, creamy solid-slightly sweet, there is a silver wrapper nearby
You test it for all 4 macromolecules and you get the following results:
Iodine: brown
Sudan III: orange
Benedict's: green
Biuret: purple
Area 4: White powder found next to a bag of graham cracker crumbs
You test it for all 4 macromolecules and you get the following results:
Iodine: blue
Sudan III: red
Benedict's: blue
Biuret: blue
Area 5: A stick of a pale yellow solid-does not dissolve in water
Iodine: brown
Sudan III: orange
Benedict's: blue
Biuret: blue
Interpretation: These all appear to be ingredients for something. Let's interpret the tests to figure it out!
Area 1-test 1:
Area 1-test 2:
What did the sucrase do?
How did this change the results?
What do you think was found in area 1? You may list several items and narrow it down after interpreting more results.
Area 2:
This substance tested positive for the presence of what?
What do you think was found in area 2? You may list several items and narrow it down after interpreting more results.
Area 3:
This substance tested positive for the presence of what?
What do you think was found in area 3? You may list several items and narrow it down after interpreting more results.
Area 4:
This substance tested positive for the presence of what?
What do you think was found in area 4? You may list several items and narrow it down after interpreting more results.
Area 5:
This substance tested positive for the presence of what?
What do you think was found in area 5? You may list several items and narrow it down after interpreting more results.
What do you think was being made in the kitchen?