What does the Biuret reagent,ethanol/filter paper,benedict solution, iodine solution test?

The Biuret reagent is used to test for the presence of proteins in a sample. Ethanol and filter paper are commonly used in chromatography to separate and identify different components in a mixture. Benedict's solution is used to test for the presence of reducing sugars in a sample, while iodine solution is used to test for the presence of starch.

Biuret Reagent:
- Tests for the presence of peptide bonds (proteins).
- A violet color indicates a positive result.

Ethanol/Filter Paper:
- Tests for the presence of fatty acids.
- When the filter paper is soaked in ethanol and then in the sample, a translucent spot indicates a positive result.

Benedict Solution:
- Tests for the presence of reducing sugars (e.g., glucose, fructose).
- A brick-red precipitate indicates a positive result.

Iodine Solution:
- Tests for the presence of starch.
- A blue-black color indicates a positive result.