Protein and Initial Chemical Test

Summer Mitchell 10/04/13
Analysis and Conclusion
1. Why was the water tested for each of the initial chemical tests?
The water was tested for each initial chemical test because it served as the controlled variable. Since water is pure oxygen and hydrogen unlike Glucose and Starch, one variable may be observed.
2. Biuret reagent will turn your skin brownish-purple. Explain why this occurs.
Biuret reagent will turn your skin a brownish-purple because Iodine detects protein in a substance by changing the color to a brown or purple shade, and since your skin contains protein it will also change color.
3. When greasy food is spilled on clothing, why is it difficult to clean with water alone?
Water cannot remove grease water is polar and grease is non-polar. They are immiscible. So when they are mixed they stay separate. But when soap or detergent is applied to the grease stain with water, the substances are allowed to mix. In more scientific terms soap molecules have ionic “heads” that dissolve in water and non polar “tails” that dissolve in grease.
4. Which food substances contain lipids? Are these results expected or not? Explain.
The eggs and chicken contained lipids. These results were expected because chicken is meat, and all meats contain lipids, and the eggs contain it also because the chickens lay them.
5. Which food substances contain simple sugars? Are these results expected or not? Explain.
The 7up and yogurt contain simple sugars. These results were expected because sugar is added to these artificial flavors are added to these substances to give them a better taste.
6. Which food substances contained starch? Are these results expected? Explain.
The potato contained starch. This was expected because I know a medium sized potato can contain up to 30 grams of carbohydrates.
7. Which substances contained protein? Are these results expected or not? Explain.
The chicken and the eggs contained protein. This was expected because proteins are found in meats and I know egg whites contain protein while the yolk contains lipids.
8. What organic molecule did we not test that is important (maybe the most important) to life? Why do you think this is the case? Give an example of how this organic molecule test can be used in a court of law.
We did not test Nucleic acids. It is one of the most important molecules because it is the building blocks of all organisms. Without nucleic acids there’d be no DNA and DNA sends messages and information for your cells to function. RNA is also made of nucleic acids. RNA is what copies the information from DNA and takes it to ribosomes. RNA is extremely important to the cell because it carries genetic information. RNA is responsible for the making of many vital proteins. The cell cannot live without RNA.
9. In a paragraph, describe what you learned from this lab. How might testing like this be applied in the real world? How does this relate to what we have been studying in class?
I learned from this lab that there are three solutions called Benedict, Biuret, and Iodine that indicate if a substance contains simple sugars, protein, and starch, and that very food contains them. I also learned that why water alone cannot remove oil because of the opposite bonds, polar and non-polar. These concepts are applied to the world when scientist wants to find out what a substance contains. This relates to what we are studying in class because with these solutions and knowledge on elements, we can determine if simple sugars, proteins, or carbohydrates are present.