Macromolecules Lab

This week, we conducted a lab testing for four different macromolecules like starch, protein, lipids, and glucose. Each pair was given a food (apple, onion, lemon, egg white, egg yolk, potato, strawberry) and they were to test which of the macromolecules was in each of them. We tested for most of the compounds by mixing them with things like biuret solution and Lugol's iodine solution and see if they changed the right color; however, to test for lipids and glucose was a bit more complicated. To test for lipids you had to take your food and rub it on a piece of brown rapping paper and let dry. To test for proteins you had to mix Benedict's solution with the food and then place it in a hot water bath. If it changed a bright orange color then it contained glucose.

My partner and I were given apples. We predicted that apples would have protein, glucose, and starch. You can see in the picture to the right that when we tested for each compound we found that it did not contain proteins.

I really enjoyed this lab. I can't speak for the other students but I know I don't normally look at the nutritional facts of the side of the box, so it was really interesting to see what was in foods that we eat on a regular basis. For instance, I would have never known an egg white contains sugar. Or that a lemon doesn't contain any of the four groups that we tested it for. For our first lab I think it was very enjoyable and interesting. It wasn't very complicated and we were working with very familiar substances which also made the lab more enjoyable. Over all I really liked that lab and I thought it was very interesting.