Biological Macromolecules

The vast complexity of a single organism, including humans, is attributed to the intricacies found within their bio molecular contents. These contents are the very small, specific pieces that make up everything from the walls of our cells, the shape of the proteins that form functional structures of the cells, or even the basic units that contain the energy required to fuel life.
The knowledge of these biomolecules can be used to analyze food contents to allow scientists to manipulate or identify the healthiest foods, to discover new molecules that can be compounded in life saving medications, or to identify disorders in our own molecules that can be corrected. These are among some of the uses knowledge of these bio molecules could provide us. In this experiment, we are going to analyze the content of two different types of substances, a banana and some curry, to identify whether or not they contain starches, sugars, or proteins.
This experiment is a very basic test of biomolecular content where identifying agents are mixed with the substances to determine their content. Our hypothesis is that the banana will contain both sugars and starches, but will not contain protein. This hypothesis is supported by the fruit’s sweet taste and starch-like structure, possibly similar to a potato, which, based on prior knowledge, is known to be a ‘starchy-food’. Our hypothesis for curry is less precise. The curry was an original recipe and the ingredients were unknown.

Based, however, on the taste and texture alone, in comparison with other known starchy foods, we would hypothesize that it does contain starch. Protein and sugar content, however, are unknown. Specifically, we predict that when added to a banana mixture, the starch and sugar identifiers will react, and when added to a curry mixture, starch identifier will react, but the two other identifiers will be unknown. Specifics of this prediction will be discussed in the next section.
Methods – To perform this study, we first mixed controls based on known substances in order to provide a baseline comparison against our experimental data. We had three identifier solutions known to react in some way to a corresponding biomolecule, and they were pippetted following strict guidelines (see below under “Pipetting Methods. ”) These identifiers were biuret, iodine, and DNSA. We tested these identifiers with solutions known to exclusively contain protein, sugar, and starch, as well as mixing them with pure water to identify what ‘no reaction’ would look like.
The test of controls and indicators shows that biuret identifies protein, iodine identifies starches, and DNSA identifies sugar. There are some complications, however, in that DNSA also reacted (however not as strong) with proteins. This means that in substances that biuret indicates protein content, DNSA will show a reaction, regardless of whether or not there is sugar in the solution. The sugar reaction is much greater than protein, but this could still possibly give inconclusive results in anything that contains proteins.
Proteins also interact with iodine however at a much different, distinguishable way so as to be less likely to influence our qualitative results. Once our controls were created and the reactions between the biomolecules and their indicators were better understood, the next part of our method involved preparing our experimental. To do this we created three tubes of each experimental substance. We diluted banana mush with water and placed it in three tubes, and diluted the curry and did the same. We then placed in the tube the appropriate amount of indicator solution, observed the results, and compared them with our controls.