• This is a picture that shows the nutrition facts of a doughnut.
Testing for Fat• For the fat test, I cut off a small piece of the doughnut and rubbed it onto a ﬁlter paper for about a minute. After ﬁnishing that, I held up the ﬁlter paper in front of a light and realized it was transparent. That showed that the doughnut had fat in it.
Testing for Starch• When testing for starch, I cut off a small piece of the doughnut and put that piece into a spotting tile and added 2 drops of iodine solution to the doughnut. The doughnut then turned black, which showed that it had starch in it.
Testing for Protein• When testing a doughnut for protein, I cut off a small piece of the doughnut, added about 2 drops of water onto it, and then crush it so that it becomes nearly powder. When this is done, I put the crushed doughnut piece into a test tube that is half full of protein solution, and I added 10 drops of biuret solution to the test tube. Then mix it together. From blue, the liquid inside the test tube turned purple, which meant the test was positive
Testing for Glucose• When I tested for glucose, I cut off a little piece off the doughnut and then added 2 drops of water onto it and then crushed it into nearly powder. Afterwards, I put the crushed doughnut piece into a test tube which was ﬁlled with 1 5th of glucose solution. Later, I added 10 drops of benedict’s solution to the test tube. I mixed carefully and then put the test tube into a water bath and waited for around 5 minutes before I took it back. I realized that the liquid inside the test tube had turned from blue to orange.
Mouth• The digestive system starts with the mouth. The teeth chop and grind op the doughnut. Then Saliva is produced and saliva contains enzymes that break down any starch in the doughnut.
Stomach• The second part of the digestion system is the stomach. The stomach is a muscular bag that mixes digestive juices with the food. Enzymes in the digestive juices starts breaking down any protein in the doughnut.
Duodenum• The third part of the digestive system is the duodenum. Enzymes in the duodenum complete breaking down all the starch and protein into sugar particles. Then bile comes and rips the fat particles into tiny bits, and then enzymes break down the fat even more.
Ileum• The fourth part of the digestive system is the ileum. In the ileum, sugars, fats, and proteins are now small enough to be absorbed. They are absorbed into the blood stream by small ﬁnger-like extensions called villi. What is now left of the doughnut is undigested waste, mostly made up of roughage and water.
Colon• The ﬁfth part of the digestive system is the colon. As the doughnut travels to the rectum, most of the water is absorbed.
Anus• The sixth and last part of the digestive system is the anus. What is left of the doughnut is a small amount of an indigestible solid waste which is stored in the rectum. The doughnut is then expelled through the anus.