Mystery Food Investigation
ntroduction
In this experiment we created standards to be able to compare a mystery substance off of. We were tasked to investigate a murder that took place by analyzing a man's last meal to find out where he had ate based on the content of his stomach. Before we could test the mystery substance we had to establish standards, so we could compare off of them. Based on the results of this lab, we believed that the victim last ate at Buffalo Wild Wings (Veliz).
Methods and Materials
We started this lab off with establishing our standards, we completed 4 tests to determine how items will appear with and without certain macromolecules. We did not have a working Sudan so we had to switch to the paper bag method. Instead of adding 5 drops of Sudan IV, waiting 5 minutes and shaking to see the results, we smeared the substances on a paper bag and waited to see how they would react.
Benedict’s (Simple Sugars Test)
First we …show more content…
one labeled “SS+” for simple sugar positive control and the other “SS-” for simple Sugar negative control. For the positive control we filled it with 2 ml of Glucose solution and for the negative control 2 ml of water (the universal negative control) in your negative control. Then we added 5 drops of Benedict’s reagent to each tube, gently shook and heated it for 3 minutes at 100 degrees celsius.
Iodine (Starch- Complex Sugars Test)
We took our two test tubes and label one “CS+” for complex sugar positive control and the other “CS-” for complex sugar negative control. In the positive control we had added 2ml of Starch solution and in the negative control 2 ml of Water. To both test tubes you will add 5 drops of Iodine and shake.
Biuret’s (Proteins Test)
We labeled our 2 test tubes “P+” for our positive and “P-” for our negative control. In the positive control we added 2 ml of Egg Albumin and 2 ml of water to our negative control. Then we added 5 drops of Biuret in each, shook them and then waited for 2 mins.
Sudan IV (Lipids Test)
Since our Sudan IV was inactive we applied a few drops of glycerol to a brown paper bag and a few drops of water on another bag. Smeared the substances into the bag and waited to see how the would change.
Results
Based on the results of this lab, we were able to set standards for positives and negatives of substances to help figure out our unknown.
We were able to determine this by the presence of simple sugar, protein and lipids which are all found in a typical meal at Buffalo Wild Wings. The way we could so easily determine this is through the standards we have established so we were able to compare our mystery meal substance to a constant. Even though we did not have a working Sudan IV in this lab we found an alternative to figuring it all out even though having it would have been nice. I personally believe these test can definitely help in the forensic field when determining parts of a crime. Below our the stands we established along with how our victims dinner held. The meal turned orange in the simple sugar test determining that it was in fact present, yet red in complex sugar determining there wasn't any. Then lilac in our protein test and the substance just sat on top of the brown paper bag in the lipid test making it positive in both proteins and
lipids.
1. Standards
Name of Reagent/Macromolecule
Positive Test Result Color
Negative Test Result Color
Simple Sugar
Orange
Light Blue
Complex Sugar
Navy
Red
Protein
Lilac
Pale, Clear Blue
Lipid
Sat on Top
Absorbed
2. Mystery Substance
Name of Test/Macromolecule
Positive or Negative?
Simple Sugar
Positive
Complex Sugar
Negative
Protein
Positive
Lipid
Positive
Discussion
Based on the results of this lab, we believed that the victim last ate at Buffalo Wild Wings. We determined this by the appearance of simple sugars, protein and lipids in the substance. We were able to find these macromolecules through multiple tests. The Benedict’s for simple sugars, Iodine for complex sugar, Biuret’s for protein and Sudan IV/paper bag for lipids. First we had to establish our positive and negative controls to compare back to all the details on this are found in the methods and materials section. Next time this is performed I'd highly suggest having a working Sudan instead of having to do the paper bag tests. Along with working on other tests while waiting for one to heat or set so you are working more efficiently.
In this experiment we created standards to be able to compare a mystery substance off of. We were tasked to investigate a murder that took place by analyzing a man's last meal to find out where he had ate based on the content of his stomach. Before we could test the mystery substance we had to establish standards, so we could compare off of them. Based on the results of this lab, we believed that the victim last ate at Buffalo Wild Wings (Veliz).
Methods and Materials
We started this lab off with establishing our standards, we completed 4 tests to determine how items will appear with and without certain macromolecules. We did not have a working Sudan so we had to switch to the paper bag method. Instead of adding 5 drops of Sudan IV, waiting 5 minutes and shaking to see the results, we smeared the substances on a paper bag and waited to see how they would react.
Benedict’s (Simple Sugars Test)
First we …show more content…
one labeled “SS+” for simple sugar positive control and the other “SS-” for simple Sugar negative control. For the positive control we filled it with 2 ml of Glucose solution and for the negative control 2 ml of water (the universal negative control) in your negative control. Then we added 5 drops of Benedict’s reagent to each tube, gently shook and heated it for 3 minutes at 100 degrees celsius.
Iodine (Starch- Complex Sugars Test)
We took our two test tubes and label one “CS+” for complex sugar positive control and the other “CS-” for complex sugar negative control. In the positive control we had added 2ml of Starch solution and in the negative control 2 ml of Water. To both test tubes you will add 5 drops of Iodine and shake.
Biuret’s (Proteins Test)
We labeled our 2 test tubes “P+” for our positive and “P-” for our negative control. In the positive control we added 2 ml of Egg Albumin and 2 ml of water to our negative control. Then we added 5 drops of Biuret in each, shook them and then waited for 2 mins.
Sudan IV (Lipids Test)
Since our Sudan IV was inactive we applied a few drops of glycerol to a brown paper bag and a few drops of water on another bag. Smeared the substances into the bag and waited to see how the would change.
Results
Based on the results of this lab, we were able to set standards for positives and negatives of substances to help figure out our unknown.
We were able to determine this by the presence of simple sugar, protein and lipids which are all found in a typical meal at Buffalo Wild Wings. The way we could so easily determine this is through the standards we have established so we were able to compare our mystery meal substance to a constant. Even though we did not have a working Sudan IV in this lab we found an alternative to figuring it all out even though having it would have been nice. I personally believe these test can definitely help in the forensic field when determining parts of a crime. Below our the stands we established along with how our victims dinner held. The meal turned orange in the simple sugar test determining that it was in fact present, yet red in complex sugar determining there wasn't any. Then lilac in our protein test and the substance just sat on top of the brown paper bag in the lipid test making it positive in both proteins and
lipids.
1. Standards
Name of Reagent/Macromolecule
Positive Test Result Color
Negative Test Result Color
Simple Sugar
Orange
Light Blue
Complex Sugar
Navy
Red
Protein
Lilac
Pale, Clear Blue
Lipid
Sat on Top
Absorbed
2. Mystery Substance
Name of Test/Macromolecule
Positive or Negative?
Simple Sugar
Positive
Complex Sugar
Negative
Protein
Positive
Lipid
Positive
Discussion
Based on the results of this lab, we believed that the victim last ate at Buffalo Wild Wings. We determined this by the appearance of simple sugars, protein and lipids in the substance. We were able to find these macromolecules through multiple tests. The Benedict’s for simple sugars, Iodine for complex sugar, Biuret’s for protein and Sudan IV/paper bag for lipids. First we had to establish our positive and negative controls to compare back to all the details on this are found in the methods and materials section. Next time this is performed I'd highly suggest having a working Sudan instead of having to do the paper bag tests. Along with working on other tests while waiting for one to heat or set so you are working more efficiently.