Biology Lab Report: Testing for Macromolecules

Only available on StudyMode
  • Download(s) : 1082
  • Published : December 21, 2012
Open Document
Text Preview
Aim:
The aim of this experiment was to determine the types of macromolecules of various foods and classify them as one or more of the following: * Carbohydrate (starch)
* Lipid
* Sugar (glucose)
* Protein
Materials:
* Test tubes
* Solutions : ( A,B,C,D,E,F, and G)
* Reagents: ( Iodine, Biuret, Benedict, Ethanol)
* Spatula
* Heating plate
* A test tube cleaning brush
* Tray
* Beaker
* Distilled water
* Pipette ( comes with reagents since they are in bottles) Method/Procedure:
Step #1: poor the solution into four different test tubes
Step #2: In the first test tube put a few drops of a reagent called "biuret". If the solution turns purple, then the solution contains protein. Step #3: In the second test tube, put a few drops of a reagent called "Iodine". If the solution turns black then the solution contains starch therefore it is a carbohydrate. Step #4: In the third test tube, put a few drops of a reagent called "Benedict". Then heat water in a beaker by exposing it to a metal heating plate. Then put the test tube in the beaker containing water. If the solution turns orange the solution contains sugar (glucose). Step #5: In the fourth test tube, put a few drops of a reagent called "Ethanol". Then swirl, in order to mix the reagent and solution. In another test tube poor in the same amount of distilled water as the new solution {therefore the ratio will be 1: 0.5: 1.5,

solution to Ethanol to distilled water} . After that poor in the new solution, consisting of the solution {elements A, B, C, D, E, F or G} and Ethanol, into the test tube containing water, if the mixture turns cloudy then the solution contains lipids {fat}. Step # 6: Repeat step #1 through step #5 for the rest of the solutions.

Results:
The results we interpreted from the solutions A,B,C,D,E,F and G are shown in the table below: TUBE| CARBOHYDRATES| PROTEINS| SUGAR| LIPIDS|
A| NO| NO| YES| YES|
B| NO| YES...
tracking img