Introduction
Organic molecules can be divided into carbohydrates, sugars, lipids, and proteins, which are analyzed in the current lab report. The combination of carbon, hydrogen, and oxygen is a carbohydrate, and it can be represented in three forms, including monosaccharides, disaccharides, and polysaccharides. Monosaccharides are composed of a single sugar, and glucose and fructose are examples of this type of organic molecule. Disaccharides can be divided into lactose, sucrose, and maltose, and they consist of two sugars.
Starch and glycogen are polysaccharides and are considered complex carbohydrates. Lipids’ primary purpose is to store energy due to their abundance in carbon-hydrogen bonds. They are crucial for maintaining the fluidity of the cell membrane, forming it, and helping keep the cell in its proper shape. Proteins help enhance the organism’s defense against external chemicals and the body’s immunity against bacteria (Li et al. 1). These organic molecules are analyzed in this laboratory report.
The experiments include a lipid test for fats, an inversion of sucrose test, an iodine test for starch, and a Biuret test for proteins. The questions in this work concern the tests typically used for fats, proteins, starch, and simple sugars, as well as the signs that the test results are positive. Another question concerns the suitable monomers for fats, proteins, and starch, and how they interact with the reagents used for the discussed tests. They are worth asking about because they reflect the essential characteristics of sugars, starches, proteins, and fats, which are critical for understanding biological reactions.
The experiments typically done for this topic include the Benedict test for sugars, the Iodine test for starch, the Buret solution for proteins, and Sudan IV for fats. The current experiments aim to determine the organic molecules in foods. The variables used for the investigation are fats, proteins, starch, and sugar.
One can measure the changes in the solution’s color. Depending on the test, they are detected by potassium hydroxide, copper sulfate, and iodine. The experiment hypothesizes that the unknown solutions contain such organic molecules as monosaccharides, polysaccharides, proteins, lipids, and disaccharides. The prediction tested in this work is that the substance has all the molecules mentioned above.
Materials and Methods
The procedures performed during the experiment included Sudan IV for fats, Buvet solution for proteins, Iodine test for starch, and Benedict test for sugars. In the Sudan IV test in liquid form, the test tubes x-4, y-4, and z-4 were used, with 4 drops per tube. In the Benedict test, similar tubes were used, and 0.5 ml of the yeast suspension was added.
In the Iodine test, the test tubes were x-2, y-2, and z-2, and 1-3 drops of I2Ki were used. In the Biuret test, 10 drops of the solution were added to tubes x-3, y-3, and z-3. The variables/treatments were monosaccharides, polysaccharides, protein, lipids, and disaccharides as the main types of organic molecules. Software was not used for data analysis.
Results
The results show that starch or glucose reacts with Iodine, changing the color from amber to yellow. Proteins or amino acids react with biuret, changing the color from blue to violet. Fats or fatty acids react with Sudan IV, altering the color from clear to pink or red. Table 1 shows the presence of organic molecules in the specific tubes.
Table 1 – Test Results
Discussion
The hypothesis assumes that the solution contains organic molecules, which can be detected using standard tests. The results generally align with this expectation, and all solutions contain organic molecules. The expected finding is that polysaccharides cannot be examined using Benedict’s test, as they are complex carbohydrates such as starch and glycogen.
Glycogen and starch are examples of complex carbohydrates that can be detected using Lugol’s test. The starch reacts with iodine, producing a black color. When iodine and starch combine, polyiodide chains are formed. The hue turns black because of the amylose, which is a straight chain. Since iodine (I2) is not soluble in water, potassium iodide (KI) is added. When they react with the solution, the negatively charged iodide releases charges, and the neutral iodine absorbs them to form polyiodide ions. Unexpected findings, in light of the hypotheses, foreground the need to conduct additional tests to identify organic molecules.
The experimental design is optimal for testing the stated hypothesis. It adequately addresses the hypotheses that are tested in the laboratory setting. The faulty assumption in the design, which confounds data interpretation, is that all organic molecules can be detected using four standard tests. New questions prompted by the results are connected to the tests that can improve the detection of organic molecules.
Conclusion
The main findings show that not all organic molecules are present in every tube for testing. There are different tests to detect various molecules based on their reactions. The lab report’s hypothesis was supported after analysis of the results.
Work Cited
Li, Jie et al. “Organic molecules with inverted singlet-triplet gaps.” Frontiers in Chemistry, vol. 10. 2022.