Macromolecules
Our Goal
Living organisms are made up of chemical building blocks which are composed of an array of biological macromolecules. Biological macromolecules are important cellular components and function in a wide variety of ways necessary for the survival and growth of living organisms. Our goal was to learn about the four different macromolecules and what each of them contributes to the beings that consume them, and also to find out how to test for these macros in the food that we eat.
Evidence of Work
This first lab we did tested for three of the macromolecules using different chemical indicators on standard solutions. We wanted to see how to identify a positive result of the certain macromolecule in each procedure.
In this second part of the lab, our group brought in two foods of choice (pretzels and bagels) and tested them for monosaccharides (carbohydrates), polysaccharides (carbohydrates), protein, and lipids (fats), using the observations of positive and negative results from part one. To do this we first had to mash the solids into liquids using a mortar and pestal and adding water to it.
CLEAR paragraph:
We discovered that pretzels are made of starch (polysaccharides) and protein. We also discovered that bagels are made up of starch and glucose (polysaccharides and monosaccharides). To find this out, we ran 4 experiments for both food types testing the macromolecules using different indicators. For the pretzels, the iodine indicator caused the liquid to change from brown to dark blue, and the Biuret indicator stiffened the liquid and made it a think consistency. For the bagel, the Benedict's solution turned the liquid bright orange after 2 minutes in 100°C, and the iodine also turned this liquid dark blue. The water tests with these indicators had no reaction, which is how we knew these results were positive. Therefore, pretzels contain polysaccharides and protein, while bagels contain polysaccharides and monosaccharides.
Concepts
Macromolecules -
A molecule containing a very large number of atoms found in your food and cells that provide living organisms with important functions for life. Most macromolecules are polymers made up of monomers. The 4 macromolecules are Proteins, Carbohydrates, Lipids, and Nucleic Acids. This lab focused on the three macromolecules you can find in your food, which are all except nucleic acids.
Polymer -
A relatively large molecule consisting of a chain or network of many identical or similar monomers chemically bonded to each other.
Monomer -
A relatively small molecule that can form covalent bonds with other molecules of this type to form a polymer.
Carbohydrate -
A macromolecule that is the main source of energy for all living things. Its monomer is a monosaccharide.
This macromolecule can be classified by its three sub-types: monosaccharides (single sugar molecule: glucose), polysaccharides (chain of many monosaccharides: starch), and disaccharides (two monosaccharides: sucrose). Both foods we tested in our lab were mostly made of carbohydrates. Some examples of carbohydrates are pasta and bread.
Protein -
A macromolecule that is used to store energy, for transportation, regulation, the structure of the organism, and in enzymes. Its monomers are amino acids. We got a positive teset result for protein in the pretzels used in our lab. Some examples of protein are meat, beans, and nuts.
Lipid -
A macromolecule that is used for long term energy storage and to build cell membranes. Its monomers are glycerol and fatty acids. Examples of lipids (or fats) include fats, oils, and waxes. This was also a test we ran on our two foods.
Nucleic Acid -
A macromolecule whose job it is to carry genetic information in cells to make proteins. Examples of this are DNA and RNA. This was not something we could test for since nucleic acids are not found in foods.
Characteristics of Life -
D.O.G.S.R.E.A.C.H. is an acronym including the characteristics that all organisms have in order to be considered living. It stands for DNA, Organization, Growth, Stimulus response, Reproduction, Energy, Adaptation, Cells, and Homeostasis. This concept was important to know for our lab because macromolecules help power cells and complete important functions in the body of all living things.
Reflection
Overall, I feel like this lab was successful and I was able to learn and practice the correct lab procedures in a classroom, since I'd never really done that before. My group of three worked well together, including Sola and Jacob, who each did their part to help complete the lab on time.
Two things I exceeded in on this lab were my work ethic and leadership. When we were first starting this project, Sola had been absent for a day and I had been sick for two, so I was worried we would fall behind. Luckily, after we got caught back up on what we had missed, we were able to pick up the material quickly and follow the lab instructions efficiently. Although we started off a little slow, I worked hard with my team to get back on track and produce quality work by practicing my conscientious learning skills found in the 6 C's. Also, I was able to take a leadership role during this lab by collaborating well with my group and giving everyone tasks to do simultaneously with each other in order to work quickly. This is another one of the 6 C's that I was able to embrace in this project.
One thing I could have improved upon in this unit are talking more about the lab findings with my group so we could all contribute to each other's analysis. I think that we could've done a better job wrapping up our work on this lab, so in the future I'll make sure to have that conversation with my group about what all of the results mean. Another aspect I could improve in for next time is planning out who would take on what before starting the experiment, and not assigning everyone jobs as we went. This made it a little bit chaotic when time was running out and we still had to rush to complete the last test. However, I am glad that everything worked out in the end and we were able to find out some interesting things about the food that we eat.