Organic Compounds Lab
Organic Chemistry Lab
AP Biology M5
Abstract:
Organic compounds are an important factor in life. Through this lab, we plan on discovering which organic compounds are in certain foods. We conducted this lab using various chemicals, an evaporation method, and heat to indicate which organic compounds are in foods like lemonade and potatoes. After conducting the experiment, we discovered that potatoes tested positively for starch and simple sugar and lemonade tested positively for simple sugars.
Introduction:
In this lab, we explored organic compounds and their importance in the ecosystem. All living things are composed of 4 organic compounds: carbohydrates, lipids, proteins, and nucleic acids. Organisms use these compounds in a process called metabolism to synthesize structures such as muscle tissue and to break down substances such as digesting food for energy.
Carbohydrates include the sugars. Their monomers are called monosaccharides and include glucose, fructose, and galactose. Two monosaccharides join to form disaccharides such as table sugar. Three or more monosaccharides combined in chemical bonds through the process of polymerization are called polysaccharides and include such important compounds as cellulose, starch, and glycogen. Breaking these complex compounds down into simpler substances is called hydrolysis.
Lipids are used for energy storage in organisms and also provide protection and insulation. They are also important in building cells and carrying chemical messages. Finally, they are important components of cell membranes. Although there is no true monomer in lipids, a common simple lipid is the triglyceride. Fats and oils are common lipids made up of triglycerides. Fats are solid at room temperature and are said to be saturated, while oils are liquid at room temperature and are said to be unsaturated.
Proteins are made up of monomers called amino acids. There are 20 amino acids in organisms. Two amino acids joined by peptide bonds are called a dipeptide. Three or more amino acids linked by peptide bonds are called polypeptide chains, and these make up proteins. The most abundant proteins are enzymes, which regulate chemical reactions.
The main objective of this experiment was to determine which organic compounds are in certain foods. Organic compounds are vital to the human body. Understanding which compounds should be put in your body to maintain a healthy body is very important. We were able to test which food contained what organic compounds by testing the food through various means, including chemicals, heat and evaporation. This experiment helped us understand what types of food would contain starch, proteins, lipids and carbohydrates.
Before conducting the experiment, we hypothesized that the lemonade drink would have simple sugars and lipids and that the potato would have starch. We came to these hypotheses’ by thinking about what we already knew about these foods. Lemonade is typically known as being a sugary substance and potatoes are made out of starch. In moderate amounts, both of these foods are essential to the human body.
Methods:
This lab was conducted in a science classroom format, at New Tech High @ Coppell. Our experiment was to test different kinds of substances for any signs of lipids, protein, sugar, and starch. The tests were spreaded among pairs to test 2 different experiments. Each group contributed to the overall data collected.
We conducted a chart to analyze if each substance were positive or negative for lipids, protein, starch, and sugar. We conducted the test to determine (1) If our hypothesis of each substance was correct (2) if our experiment were to test positive or negative.
Discussion:
In this organic chemistry lab, the group had a small portion of assumptions that were made correct. The hypothesis laid out what the group believed the results would be for both the potato and the lemonade. The instructions were kept as simple as the organic chemistry lab we did a day early with different ingredients. The group kept the all the same lab equipment as before which allowed for the results to mirror the ones received the day before as long as the ingredient being tested received a positive result for starch, simple sugars, carbohydrates, or lipids.
Along with the equipment, the experimental design was also kept the same as the organic chemistry lab that was conducted the day before. The group’s purpose behind keeping the experimental design the same as the other organic experiment was because we were still testing for the exact same things just in different substances. In this new experiment the substances were lemonade and potato.
Results:
Simple Sugars Test
The first test taken at the study showed that the substance with benedict's and glucose turned out positive indicating that it contained simple sugars. We know the result was positive because it changed form a light blue to a bright orange (Table 1) .The second test taken at the study site showed that the substance with benedict's and water turned out negative indicating that it did not contain simple sugars (Table 1). The third test taken at the study site showed that the Potato contained simple sugars. We know this because it changed from a light blue to a yellow-green color indicating that it was positive (Table 1).The fourth test taken at the study site showed that the Lemonade contained simple sugars. We know this because the color did changed indicating that it was positive (Table 1).
Starch Test
The first test taken at the study showed that the substance starch solution and iodine turned out positive indicating that it contained starch. We know the result was positive because it changed form a light yellow to a dark blue (Table 2) .The second test taken at the study site showed that the substance with iodine and water turned out negative indicating that it did not contain simple sugars (Table 2). The third test taken at the study site showed that the Potato contained starch. We know this because it changed from a light yellow to a dark blue color indicating that it was positive (Table 2).The fourth test taken at the study site showed that the Lemonade contained no starch. We know this because the color did not change indicating that it was negative (Table 2).
Protein Test
The first test taken at the study site showed that the gelatin, CuSo and NAOH it turned out positive indicating that it contained protein. We know the result was negative because it did not change colors (Table 3) .The second test taken at the study site showed that the solution of water, CuSo and NAOH turned out negative indicating that it did not contain protein (Table 3). The third test taken at the study site showed that the Potato did not contain protein. We know this because the color did not change indicating that it was positive (Table 3).The fourth test taken at the study site showed that the Lemonade contained no protein. We know this because the color did not change indicating that it was negative (Table 3).
Lipid Test
The first test taken at the study site showed that the water was not a lipid. We know this because the stain on the paper towel was not translucent. The second test taken at the study site showed that the oil was a lipid. We know this because the stain was translucent and did not fully dry. The third test taken at the study site show that the potato was not a lipid. We know this because the stain on the paper towel was not translucent (Table 4). The fourth test taken at the study site shows that the lemonade is not a lipid. We know this because the stain on the paper towel was not translucent (Table 4).
Conclusion:
The purpose of this lab was to learn about how to test for organic compounds. For our experiments that had a lot of preparations and minor errors we have learned how to determine if the substances we used had lipids, starch, sugar, and protein. For our tests we had a 3:5 ratio of a positive to negative amount for each experiment. We learned that the protein test for the potato does not contain protein, within that certain amount. For instance, a whole potato does contain a few grams, but through our experiment it showed no sign of protein which was very interesting even though we used a small amount. There should be a fine line among each test for the substances, such as the potato and lemonade did test for at least one positive outcome which our predictions were correct for the most part.
