Digestion Lab:
Question:
How Does Saliva Help Digestion?
Hypothesis:
If iodine changes color when a starch is present, then when food is combined with saliva, iodine will show that saliva chemically changes starch into sugar. If Benedict’s solution changes color when a sugar is present, then Benedict’s solution will show that saliva chemically changes starchy foods into usable sugars for the body.
Materials:
1.) 8 ziploc bags, labeled
2.) Water in jars
3.) Saliva
4.) Eye-droppers
5.) Iodine in jars
6.) Benedict’s solution in jars
7.) Unsalted cracker crumbs
8.) Measuring Spoons
9.) Pyrex measuring cup with hot water
10.) Hot pot
Variables:
Control:
Independent:
Dependent:
Procedures:
1.) Separate and label each of the eight bags.
2.) Create two charts for the two experiments you will be conducting (See Below):
3.) Put 1 tsp. of water in each of the eight bags.
4.) Have 4 students break an unsalted soda cracker into tiny crumbs and drop into (Iodine Blue bags #3 and 4) and (Benedict’s Red bags #3 and 4).
5.) Select 5 students at your table to be responsible for one of the 5 bags in this experiment. Send 5 students outside to add plenty of saliva in their bags. These students will be the scientists for their experiment.
6.) Add 2 drops of iodine solution (in jar) to the 4 zip-lock bags described in the chart. Seal and observe.
7.) Record your information in the Results Box of chart.
8.) Add 1 squirt of Benedict’s solution (in jar) in 4 zip-lock bags described in the chart. Seal and observe.
9.) Place all 3 bags in the Pyrex cup with hot water. Wait 3 minutes.
10.) Record your information in the Results Box of chart.
Data Analysis:
Conclusion: