Question

1. the test results below indicate the presence of which nutrient? monosaccharide polysaccharide protein lipid

Explanation:

• Benedict's test: Used for monosaccharides (reducing sugars). A positive result would show a color change (e.g., green, yellow, orange, red). Here, the solution remains blue (negative for monosaccharides).
• Lugol's test: Tests for polysaccharides (starch). A positive result is a purple - black color. But we are asked about the nutrient indicated by the overall tests.
• Biuret test: For proteins. A positive result is a violet color. Here, the solution is blue (negative for proteins).
• Sudan Red test: Specific for lipids. A positive result shows the dye dissolving in the lipid layer (as seen in the image with the red - colored layer, indicating the presence of lipids).

Answer:

lipid