As living beings we all rely on some form of energy to survive. One form of energy for humans is food. Food contains macromolecules that are important energy sources for biological organisms and these include carbohydrates, lipids, and proteins. Carbohydrates (carbs) are what either gives us energy or store energy, they are what help us to keep our bodies going. There are two forms of carbs: simple sugars and starch (complex). Simple sugars are found in fruits, vegetables and milk products while starch is found in breads and cereals. Proteins are in the foods we eat, and they are digested into amino acids that are later used to replace these proteins in our bodies. There are 20 different amino acids, but since our bodies cannot provide 8 of these amino acids, it is important for our diet to contribute these amino acids which are found in meats, fish, tofu, eggs, nuts, etc. Lipids are known as fats and there are two types: saturated and unsaturated. Saturated fats remain solid at room temperature and are unhealthy, while unsaturated fats remain liquid at room temperature are healthier. Saturated fats include cheese, butter, ice-cream and milk whereas unsaturated fats include corn oil, avocados, olive oil and natural peanut butter. In this lab, I performed a variety of tests to determine the nutritional content of food.
The tests performed included the: Benedict test, Lugol test, Biuret test and Sudan Red Test. The Benedict test involves the reagent Benedict’s solution and it tests for monosaccharides within the sample tests. When it comes in contact with a monosaccharide, the solution in the test tube turns pink and when there is no reaction, there is no colour change. The Lugol test involves the reagent Lugol’s Iodine and it tests for polysaccharides (complex sugars) within the sample tests. When it comes in contact with a complex sugar, the iodine in the test tube turns dark purple in the presence of starch. And when there is no reaction, there is no colour change. The Biuret test involves the reagent Biuret’s solution, which is a solution of potassium hydroxide (KOH) and copper sulfate (CuSO4). It tests for proteins within the sample tests and when proteins are present, the solution in the test tube turns purple and when there is no reaction, there is no colour change. The Sudan Red test involves the reagent Sudan Red which is a fat-soluble dye that tests for lipids within the sample testes. When it comes in contact with lipids, the dye will be absorbed into the lipids, and will appear as concentrated spots of colour in the test tube. When there are no coloured spot present, it means that there are no lipids present.
METHOD AND MATERIALS Refer to the Gizmo simulation worksheet
OBSEVATION AND RESULTS
MACROMOLECULES IN FOOD This chart shows the results of the tests performed. The food sample that contains carbohydrates/monosaccharides is sample: A. The food