| Substance vs. Starch Presence | ||
| Substance | Resulting Color | Presence of Starch? |
| Positive Control: Starch | Dark Purple | Yes |
| Negative Control : Cellulose | Brownish red color | No |
| Food Product: Apple | Dark Purple | yes |
| Food Product: Potato | Dark Purple | yes |
| Saliva: Amylase | Brownish red color | No |
Post Negative Control -Lab Questions
1. What were your controls for this experiment? What did they demonstrate? Why was saliva included in this experiment?
2. What is the function of amylase? What does amylase do to starch?
3. Which of the foods that you tested contained amylase? Which did not? What experimental evidence supports your claim?
4. Saliva does not contain amylase until babies are two months old. How could this affect an infant’s digestive requirements?
5. There is another digestive enzyme (other than salivary amylase) that is secreted by the salivary glands. Research to determine what this enzyme is called. What substrate does it act on? Where in the body does it become activated, and why?
6. Digestive enzymes in the gut include proteases, which digest proteins. Why don’t these enzymes digest the stomach and small intestine, which are partially composed of protein?