Biological molecules.

• Starch test: blue - black


  starch present
• Starch test: pale brown 


  Starch absent
• Ethanol emulsion test


  Test for lipids
• Ethanol emulsion test: White emulsion


  Lipid present
• Ethanol emulsion test: clear solution


  Lipids absent
• Benedict's test


  Test for glucose and maltose
• Benedict's test: Brick red


  reducing sugar present
• Benedict's test: pale blue


  reducing sugar absent
• Biuret test

  Test for protein
• Biuret test: purple colour


  protein present
• Biuret test: pale blue


  protein absent