Biology Question
Find Background Research, Lab 3 Assignment
Complete this assignment and attach your document as a word file to the correct dropbox on Elearning before the due date. (20 points)
- You did three different simulations this week. In the chart below, I would like you to identify all of the variables (independent, dependent and ones being held constant) that you found while performing each simulation. Some were given to you in the simulation protocol and/or can be deduced by what you experienced. List them all below.
| Simulation | Variables |
|
Test for Fat |
List your variable here. This list can be as long as it needs to be.
|
|
Emulsification of Lipids |
List your variable here. This list can be as long as it needs to be.
|
|
Test for Protein |
List your variable here. This list can be as long as it needs to be.
|
- Using your chart in #1, highlight in red the dependent variable in each trial. Highlight in green the independent variable you changed in each trial. Highlight in blue every additional variable you could change in each trial (these are things that were held constant but could actually be changed in a subsequent trial).
- Your simulation of Emulsification of Lipids resulted in a qualitative description of the outcome from the experiment. How could you take the same apparatus that you have available in the simulation to make a quantitative test? If I gave you 3 unknowns that may or may not be an emulsifier, how would you determine with the given equipment something that provides a number that describes what you observe? You can add anything to the process that you have available to you at home, your apartment or your dorm, but no special scientific equipment. Make sure you explain in detail so a TA or myself can understand what you intend.
- Find a background research article that supports what you wrote in #3 above. Write the correct APA format of the source below. Also, if you were to use this source in submitted work, it would need a citation. Write the citation in the space provided.
- If we were in a physical lab, we could do a biuret assay to determine the amount of protein in a solution. We could measure the amount of light absorbance at 540 nm using a spectrophotometer. This would give us a number that would allow us to determine the amount of protein in an unknown solution.
To do this, we first need to create a standard curve of known amounts of protein. A standard curve uses data results from known amounts of a substance to create a line on a graph. Work through the process of creating a standard curve using the attached excel file. You should be making a scatter chart. The data you are using come from Keppy and Allen, 2009. Attach your excel file that includes your graph to the assignment dropbox when you submit this assignment.
- Three unknown protein solutions were measured using the biuret assay and the resulting absorption at 540 nm was observed. Using your standard curve created above, determine the amount of protein in each unknown. It is not easy to get an exact number from a graph. Get as close as you can within the limitations of the graph.
| Unknown | Absorbance at 540 nm | Amount of Protein (ug/ml) |
| A | .3000 | |
| B | .2000 | |
| C | .1000 |
- Now that you understand proteins and lipids, I want you to combine and connect both ideas. Synthesize some new ideas. What would be required of a protein to act as an emulsifier? Using your best understanding of proteins, amino acids and emulsifiers, describe a protein that could function as an emulsifier in the simulation you did this week. Make sure you explain in detail so a TA or myself can understand what you intend.
