St. Paul College PasigHigh School DepartmentSchool Year 2014-2015

Name: Brindle, Lee (Kia), Marquez, Samson, Sta. Ana Date Submitted: February 24, 2015Year and Section: IV-1 Teacher: Ms. Baccay

Laboratory Report No. 1Testing Biomolecules

I. ObjectivesAt the end of this experiment the students should be able to: Observe the reaction of the different chemicals to be processed to the food samples used Identify whether the food samples used contain starch and; Distinguish whether the food sample is a component of the reducing sugars through the tests

II. MethodologyA. Materials Fehlings Solution A Fehlings Solution B Tincture of Iodine Solution Hydrogen Chloride 1 Tongs 1 50 ml Beaker 1 10 ml Graduated Cylinder 3 Test Tubes 2 Medicine Dropper 1 Spatula 1 Mortar and Pestle 1 Alcohol Lamp 1 Test Tube Brush 1 Test Tube Holder Cream-O 1 loaf of bread MilkB. ProcedurePrepare all the materials needed for the experiment. Get small samples from each food items. Mash the food item with 10 mL of water. Make sure that the food is completely mashed. Completely mashed food can result a maximum effects. Divide each mashed mixture into two equal parts. Label two test tubes and put the divided food mixture equally in two test tubes. In first test tube, put 2-3 drops of tincture of iodine. In another test tube, put 2 mL of hydrogen chloride. Heat the test tube after until its contents crumble or boil. Add 1 mL each Fehlings solution A and B. Stir the mixture before and reheat the mixture. Stop heating the text tubes as soon as the contents stop changing their color. Record all the observations during the process. Repeat the process for the other two food samples. III. Data and Calculations

Experimenters have prepared the materials for the testing of Biomolecules. Three different food materials, bread, cream-o and milk, were prepared and the experimenters mashed them completely up with the amount of water. The food mixture of bread and cream-o had viscid character, and the food mixture of milk was a complete fluid, liquid.

With the food mixture in different test tube with equal amount, Iodine was dropped to the first test tube of the first food sample, bread, which color shown ivory. After the drop of chemical, the color was in blackish purple as observed by the experimenters. In the next test tube of the same food sample, Hydrogen Chloride, Fehlings solution A, and Fehlings solution B was dropped. This was heated after the drop of different chemicals. When it was heated for the period of time in alcohol lamp, color of the mixture started turning in yellow. For the organized summary, reader can check followed Table 1 of the paper.

Test Tube ATest Tube B

starting color of the mixtureIvory

heated/

not heated/

chemical/sIodineHydrogen ChlorideFehlings solution A Fehlings solution B

observationsturned black/purple in colorturned yellow in color

Table 1: Food Sample 1 - Bread

The next food sample was Cream-O started with the color of brown which was closely similar to black. There was black color observed when Iodine was dropped to the first test tube similar to the first food sample, but this time with some white spots visible. In the next test tube of the same food sample, Hydrogen Chloride, Fehlings solution A, and Fehlings solution B was dropped. This was heated after the drop of different chemicals. When it was heated for the period of time in alcohol lamp, color of the mixture started turning extremely black. For the organized summary, reader can check followed Table 2 of the paper.

Test Tube ATest Tube B

starting color of the mixtureBlackish Brown

heated/

not heated/

chemical/sIodineHydrogen ChlorideFehlings solution A Fehlings solution B

observationsblack in color with some white spots visibleextremely black

Table 2: Food Sample 2 - Cream-O

The last food sample was milk. It was complete fluid-liquid mixture unlike the other two mixtures. Mixture started with the opaque white liquid. When Iodine was dropped to the first test tube, bright yellow with a few spots of light yellow were observed. In the next test tube of the same food sample, Hydrogen Chloride, Fehlings solution A, and Fehlings solution B was dropped. This was heated after the drop of different chemicals. When it was heated for the period of time in alcohol lamp, color of the mixture started turning its color to sky blue with a mixture of blue. After few more minutes of heating, mixture turned its color again to the yellow. There were no more changes in color after. For the organized summary, reader can check followed Table 2 of the paper.

Test Tube ATest Tube B

starting color of the mixture opaque white

heated/

not heated/

chemical/sIodineHydrogen ChlorideFehlings solution A Fehlings solution B

observationsBright yellow with a few spots of light yellow visiblesky blue with a mixture of blue and yellow

Table 3: Food Sample 3 - Milk

IV. Results and Discussion

Nutrients are the substances of different compounds that supply the body with the energy and the building blocks of molecules. Sugar and starches make up a group of organic compounds called carbohydrates, which are important in supplying your body with energy along with some starches that provide the necessary indigestible fiber that helps in the process of digestion. Proteins, mainly organic compounds are essential in growth and repair. Lipids are the organic compounds that can supply as much as four times the amount of energy as carbohydrates or proteins.

Performing tests which can identify the presence of the different organic compounds in the food samples; bread, cream-o and milk using the indicators and chemical substances that help determine their reaction in a certain way when substances are present or added.

During the experiment, the group made use of the following food items: a) A slice of bread, b) Cream-O (sandwich biscuit), c) Milk. These three types of food were crushed into grain-like pieces and were divided to be placed in two separate test tubes. The bread placed in test tube A, containing the iodine, caused a reaction which made the mixture appear to be black or dark purple. This hints the presence of starch in the mixture. Test tube B of the bread, on the other hand, was combined with Fehlings solution A and B. The mixture which turned yellow, hints the presence of reducing sugars. Reducing sugars are any sugar that either has an aldehyde group or is capable of forming one in solution through isomerism.

The iodine test is a test to identify the presence of starch. The iodine solution was dissolved in an aqueous solution of potassium iodide reacts with the starch, producing a purple-black color. As observed all of the food samples namely bread, cream-o and milk produced a reaction positive to the iodine test resulting that the food samples contain the starch.

The Fehlings test is a way to determine whether a certain food sample contain reducing sugars through a series of tests. Types of reducing sugars would include glucose, fructose, lactose, maltose, glyceraldehyde and arabinose. It is a kind of sugar that reduces some of the chemical compounds through a certain oxidation reaction. The test contains copper (II) ions, which are blue in color which is the reason behind the reaction of the milk towards the reactant that the solution became blue/sky blue with a little mixture of yellow in color.

V. Conclusion

VI. References

Biochemistry: Nutrients & Digestion of Biomolecules. (n.d.). Retrieved February 21, 2015 from http://quizlet.com/29842956/biochemistry-nutrients-digestion-of-biomolecules-flash-cards/

Fehlings Solution. (n.d.). Retrieved February 21, 2015 from http://en.wikipedia.org/wiki/ Fehling's_solution

Iodine Test. (n.d.). Retrieved February 21, 2015 from http://en.wikipedia.org/wiki/Iodine_test

Hydrochloric Acid. (n.d.). Retrieved February 21, 2015 from http://en.wikipedia.org/wiki/ Hydrochloric_acid

Reducing Sugar. (n.d.). Retrieved February 21, 2014 from http://www.oocities.org/rosa_chan_99/carbohydrates/reducing.html

Rinzler C.A. & DeVault, K. (n.d.). The Human Digestion Process (or, What Happens after You Eat Food).Retrieved February 21, 2015 from http://www.dummies.com/how-to/content/the-human- digestion-process.html

Starch-Iodine. (n.d.). Retrieved February 21, 2015 from http://www.elmhurst.edu/~chm/vchembook /548starchiodine.html

Wolfe, I. (2015). How to Test for Low HCL Acid in the Stomach. Retrieved February 21, 2015 from http://www.livestrong.com/article/493568-how-to-test-for-low-hcl-acid-in-the-stomach/

Testing for Biomolecules in Food. Retrieved February 21, 2015 from http://tigerbiology.pbworks.com/f/Testing+For+Biomolecules.pdf