We developed a simple lab experiment demonstrating the effects of amylase that anyone can do with some basic equipment. This is probably an experiment that others have developed, I just haven't come across it before. All that is needed is a test tube, chlorine free water, saltine crackers, potassium iodide, and spit. Tap water can be de-chlorinated by letting it set out for 24 hours and potassium iodide (IKI) and test tubes can be purchased on-line.
Here are the steps to this experiment:
1. Crush up part of a saltine cracker into a fine powder. You don't need much, only enough to cover the bottom of a test tube. (this imitates the effects of chewing)
2. Place the crushed cracker in the bottom of a test tube, you only need enough to cover the bottom.
3. Add an equal amount of de-chlorinated water to the test tube and mix thoroughly.
4. Add one or two drops of potassium iodide (IKI) to the water-cracker mix and mix again thoroughly. At this point much of the cracker should turn a brown color. This is a result of the IKI staining starches in the cracker brown.
5. Double (or slightly more) the total volume in the test tube with saliva. Yes, just let some spit accumulate in your mouth and then spit into the test tube.
6. Mix and wait to see what happens.
|Cracker ground up into fine powder. A small amount like this works best. Too much cracker makes the experiment work a lot slower.|
|Cracker with de-chlorinated water added.|
|Cracker and water with an added drop of potassium iodide (IKI). Notice the darker appearance which is the result of IKI staining starch brown.|