IDENTIFICATION OF BIOLOGICAL MOLECULES CHEMICAL LAB TESTS

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Benedict’s Reagent - A Test for Simple Sugars (monosaccharides and some disaccharides) Upon heating, Benedict’s Reagent for 4-6 minutes in a boiling water bath, a small amount of sugar in the sample will turn yellow-green and a large amount of sugar will turn orange to brick red.

Lugol’s Iodine - A Test for Starch (a polysaccharide)

Lugol’s Iodine (Iodine Potassium Iodide Solution) will turn deep blue-black to purple-black in the presence of starch.

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IDENTIFICATION OF BIOLOGICAL MOLECULES CHEMICAL LAB TESTS

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Biuret Solution – A Test for Proteins (peptide bonded molecules)

Biuret Solution contains sodium hydroxide and copper sulfate which, upon heating, reacts with the peptide bonds in proteins to give an attractive purple color.

Brown Paper Test - A Test for Lipids (fats, oils and waxes) Lipids will leave an oily, translucent smear when absorbed into brown paper. This is easier to see when held up to a light or sunny window.

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