In this lab, you will 1. Learn the names of specific indicators 2. Learn the what a specific indicator test for 3. Be introduced to three organic compounds, proteins, carbohydrates and lipids

 Biuret Solution Blue Color  ?  Protein present  Benedict’s Solution Blue Color  ?  monosaccharide  Iodine Solution Orange or Brown  ?  polysaccharide All three indicators show a color change when mixed with a specific organic compound.

Iodine Chemical Indicators for Carbohydrates: Initial Color

Chemical Indicator for Protein: Initial Color

Positive Control Test Tubes: Indicator + Organic Compound Negative Benedict ’s Positive Benedict’s Negative Iodine Positive Iodine

Test Tube # Organic Compound Solution IndicatorInitial ColorFinal Color 1MonosaccharideIodine orange/brown 2DisaccharideIodine orange/brown 3PolysaccharideIodine orange/brown blue-black 4ProteinBiuret Solution blue purple Tube # Organic Compound Solution IndicatorInitial Color Final Color Location of Color 1Monosaccharide Benedict’s Solution blue orange NA 2Disaccharide Benedict’s Solution blue NA 3Polysaccharide Benedict’s Solution blue NA 4Vegetable Oil Sudan Red

1. Which two indicators test for a carbohydrate? 2. Which indicator checks for a protein? 3. If a monosaccharide is present in the food, what indicator turns orange? 4. If a polysaccharide is present in the food, what indicator turns blue-black? 5. What is observed with a positive test for proteins? 6. What would happen to the Iodine if you mixed it with water? Why? 7. Which indicator has to be heated before a change occurs? 8. Name all the organic compounds tested in the lab.

The more red; the more lipid present.