Biochemistry of Foods
BACKROUND INFORMATION
Starch is stored by the plants after photosynthesis takes place.
Glucose is made through photosynthesis, photosynthesis makes the glucose, the glucose is transferred into the grass that the cows eat, and the cows make the milk that we eat or drink in dairy products. On the other hand, if the food, such as a vegetable, was growing in the ground, it could contain glucose.
Protein is also made through the photosynthesis process. Once again, the glucose is in the food that the cows eat, we eat the cowís meat or drink their milk, and we get protein from the glucose and protein that the cows have eaten.
Fats are also made through the photosynthesis process. The glucose contains fat, which means plants and grasses contain fat. The cows eat the plants and grasses, and we eat or drink the fats. Itís almost the same process of getting protein, except fat is a stored glucose, and may be used later.
Vitamin C. Rachael read somewhere in a book that red peppers have more Vitamin C than an orange.
HYPOTHESIS
1.) Potatoes will contain starch.
2.) Yogurt will contain glucose, fats, and protein.
3.) Hamburger will contain protein and fat.
4.) Red Pepper will contain Vitamin C and glucose.
PROCEDURE
We took a 104.5g piece of potato chopped it up in the blender and added 400 ml of buffer water. This created a clear enough solution to be able to see color changes. Then we did these tests: BSCS Protein, BSCS Glucose, BSCS Starch, BSCS Vitamin C, BSCS Chloride, and BSCS Fat.
We took a 22.4g piece of hamburger chopped it up in the blender and added 200ml of buffer water to get a clear solution. Then we did the BSCS tests shown above.
We took a 14.3g piece of red pepper chopped it up in the blender and added 150ml of buffer water to get a clear solution. Then we did the BSCS tests shown above.
We took 2tsp of yogurt and diluted it with 25ml of water to get a clear solution. Then we did the BSCS tests shown above.
OBSERVATIONS Tests

Food Tested BSCS
Protein BSCS
Glucose BSCS
Starch BSCS
Vitamin C BSCS
Chloride BSCS
Fat
Potato - - + - - -
Yogurt
+ - + + + +
Hamburger
+ - - - - +
Red Pepper - + + - - -
CONCLUSION
Hypothesis 1 was correct because in the BSCS tests the only thing potatoes were positive for was starch.
Hypothesis 2 was incorrect because yogurt contained more than we thought in our hypothesis and it didnít contain glucose.
Hypothesis 3 was correct because in the BSCS tests it showed there were fats and proteins in the meat.
Hypothesis 4 was incorrect because red peppers didnít contain Vitamin C which we thought it would.
A few sources of error were if you had chunks of the food in your solutions. This may cause wrong data from the BSCS tests. Another source of error was if you got the solution clear enough to be able to see the color changes caused by the tests.
I learned that food is made up of many kinds of molecules. I also learned that yogurt contains starch. I wouldnít expect to find starch in yogurt because it isnít anything like potatoes, which contains large amounts of starch. I learned how to make a food into a solution. I also learned how to design an experiment and how to write a procedure for the lab.