Biological Tests for Macromolecules

Testing for Glucose

• Benedict's test is used to detect the presence of glucose.
• The solution changes color from blue to green, yellow, orange, or brick-red depending on the concentration of glucose.

Testing for Starch

• Iodine test is used to detect the presence of starch.
• The iodine solution changes color from brown/yellow to blue-black.

Testing for Protein

• Biuret test is used to detect the presence of protein.
• The solution changes color from blue to purple.

Testing for Fat

• The emulsion test is used to detect the presence of fat.
• A white, cloudy emulsion (milky layer) indicates the presence of fat.

Benedict’s Test for Glucose

• A blue solution of Benedict’s reagent turns to green, yellow, orange or brick-red in the presence of glucose.
• The color change depends on the concentration of glucose in the sample.
• A hot water bath is used to speed up the reaction.

Iodine Test for Starch

• A brown iodine solution turns blue-black in the presence of starch.
• The test can be performed in a test tube or on a spotting tile.

Biuret Test for Protein

• A blue Biuret solution will turn purple in the presence of protein.
• Biuret solution is a mixture of sodium hydroxide and copper sulfate.

Emulsion Test for Fat

• A milky layer (emulsion) forms in the presence of fat.
• Fat dissolves in ethanol.
• Adding water to an ethanol solution with fat results in an emulsion.

This quiz covers the different tests used to detect macromolecules such as glucose, starch, protein, and fat. Each test's specific reaction and color change are highlighted, providing a comprehensive overview of biochemical testing methods. Test your knowledge on these essential laboratory techniques.