Lab 2 Proteins and Starches
Lab2: Testing for Proteins and Starches
In this lab 8 total substances were tested to find out whether they are a Protein or a Starch.
It is my belief that only 1 or two of each of the substances in test 1( proteins) and test 2 (starch) will test positive for either protein or starch.
For this lab the following materials were needed to complete the experiments in test 1 for proteins: Di water, ev milk, 50% egg solution, 1% sucrose, 4 test tubes, 1 test tube rate, safety glasses, pipets and the reagent solution. For test 2 for starches the following materials were used: Di water, 1% starch solution, onion juice, sucrose solution, iodine reagent, 4 test tubes, test tube rack and pipets.
In test 1 and test 2 each solution was placed in a separate test tube with the corresponding reagent added to each as well. In test one for proteins each substance that showed a purple color it indicated a positive result for proteins. Any solution that stayed blue is to be considered negative for proteins. The Di water in test tube one resulted in a blue color once the reagent was added. In test tube 2 Evaporated milk had the reagent added for a resulting color of milky purple. In test tube 3 the egg solution the color turned purple once the reagent was added. Finally for test one in test tube 4 containing sucrose turned light blue once the reagent was added for a negative result.
In test 2 for starch the first solution used was Di water as the control similar to test 1. Test tube one resulted in a yellow color and a negative test. Test tube 2 with 1% starch turned light purple once the iodine reagent was added. The iodine reagent is used in test two because it is the only reagent that will indicate traces of starch. In test tube 3 onion juice turned yellow once the iodine was added and finally in test tube 4 the sucrose solution also turned yellow.
For both tests 1 and 2 the results were as expected. In test 1 for proteins the solutions evaporated milk and 50% egg both
In this lab 8 total substances were tested to find out whether they are a Protein or a Starch.
It is my belief that only 1 or two of each of the substances in test 1( proteins) and test 2 (starch) will test positive for either protein or starch.
For this lab the following materials were needed to complete the experiments in test 1 for proteins: Di water, ev milk, 50% egg solution, 1% sucrose, 4 test tubes, 1 test tube rate, safety glasses, pipets and the reagent solution. For test 2 for starches the following materials were used: Di water, 1% starch solution, onion juice, sucrose solution, iodine reagent, 4 test tubes, test tube rack and pipets.
In test 1 and test 2 each solution was placed in a separate test tube with the corresponding reagent added to each as well. In test one for proteins each substance that showed a purple color it indicated a positive result for proteins. Any solution that stayed blue is to be considered negative for proteins. The Di water in test tube one resulted in a blue color once the reagent was added. In test tube 2 Evaporated milk had the reagent added for a resulting color of milky purple. In test tube 3 the egg solution the color turned purple once the reagent was added. Finally for test one in test tube 4 containing sucrose turned light blue once the reagent was added for a negative result.
In test 2 for starch the first solution used was Di water as the control similar to test 1. Test tube one resulted in a yellow color and a negative test. Test tube 2 with 1% starch turned light purple once the iodine reagent was added. The iodine reagent is used in test two because it is the only reagent that will indicate traces of starch. In test tube 3 onion juice turned yellow once the iodine was added and finally in test tube 4 the sucrose solution also turned yellow.
For both tests 1 and 2 the results were as expected. In test 1 for proteins the solutions evaporated milk and 50% egg both