Dancer is studying body systems in science, right now it's the digestive system. Today we are making a simple model of a stomach.
A gallon zipper topped freezer bag is the stomach, the food colors are chemicals and enzymes, the banana and crackers are food that was eaten, three tablespoons of water, the saliva, of course.
The crackers are partially crushed, to emulate chewing,
and the banana is sliced, again to show chewing. This processing before the stomach represents the mechanical digestion that occurs in the mouth with chewing.
In goes the spit.
The enzymes and chemicals.
The kids squeezed the bag for 30 seconds each. The squeezing action is like that of the muscles in the stomach, this is mechanical digestion as well.
Later, in the large intestine, undigestable and the non digested food remains are stored and water is recycled back to the body.