Question

click each test tube to test for the presence of polysaccharides. record all color changes in the data table.
the mystery food sample contain polysaccharides because the color of the test tube was
done
lugols solution
polysaccharide mixture
water
mystery food sample

Explanation:

To determine if the mystery food sample contains polysaccharides, we use Lugol’s Solution (iodine test). Lugol’s Solution turns blue - black in the presence of polysaccharides (like starch, a type of polysaccharide).

1. First, recall the positive test for polysaccharides with Lugol’s Solution: When Lugol’s Solution is added to a substance containing polysaccharides, the solution turns blue - black.
2. The “Polysaccharide Mixture” test tube (positive control) would show a blue - black color when Lugol’s Solution is added. The “Water” test tube (negative control) would not show this color change.
3. For the mystery food sample, if it contains polysaccharides, when Lugol’s Solution is added (by clicking the test tube), the color of the test tube will change to blue - black (or a similar dark blue/black color, depending on the concentration of polysaccharides).

So, the mystery food sample contains polysaccharides because the color of the test tube was blue - black (or the appropriate color indicating a positive Lugol’s test for polysaccharides).

Lugol's Solution (iodine) turns blue - black in the presence of polysaccharides (e.g., starch). The positive control (Polysaccharide Mixture) shows this color, and if the mystery sample shows the same blue - black color after adding Lugol's Solution, it contains polysaccharides.

Answer:

The mystery food sample does contain polysaccharides because the color of the test tube was blue - black (or the color indicating a positive Lugol's test for polysaccharides).