Question

click each test tube to test for the presence of proteins. record all color changes in the data table. the mystery food sample contain protein because the test tube was does not does. done biuret solution gelatin water mystery food sample

Explanation:

Biuret solution turns violet in the presence of proteins. Gelatin, which contains proteins, shows a color - change to pinkish - violet. If the mystery food sample tube shows a similar color change, it contains protein. If not, it does not.

Answer:

If the mystery food sample test - tube has a color change similar to the gelatin tube (violet or pinkish - violet), the answer is "does"; if it remains like the water tube (no color change), the answer is "does not".