Lab 2
Lab 2: Protiens and Starches
Purpose:
An introduction to testing procedures for two large, organic molecules: proteins and starches.
Hypothesis:
In the test for protiens the water, being that it is inorganic will not test positive for protiens; it will serve as the negative control. The milk and 50% egg solution should test positive for protien as they are subsatnce derived from animals which contain protiens in order to carry the functions of life. The sucrose will test negative due to the fact that it is a carbohydrate and not a composition of organic material but rather a single part.
In the test for starches, water again will serve a the negative control for the experiment becasue it is inorganic. it appears obvious the 1% starch solution will test positve for starches becasue it is starch. The onion juice should carry starch due to the fact that starch is stored energy for plants and onions are very bulbous, while the sucrose solution again will not test positive because sucrose is only a part of starch.
Materials:
Test tube rack
4-5 test tubes
Transfer dropper
Deionized water
Evaporated milk
1% sucrose solution
1% starch solution
50% egg white solution
Onion juice
Biuret reagent
Iodine
Methods:
Protien test:
1. Set up four test tubes in the test tube rack.
2. Label each test tube by the tested material (deionized water, evaporated milk, 50% egg white, 1% sucrose)
3. Fill each test tube with 3ml of the testing solutions, respectively
4. Add five drops of biuret reagent to each test tube
5. Swirl each test tube until fully mixed
6. Record the color of each test tube as results Starch test: 1. Set up four test tubes in the test tube rack. 2. Label each test tube by the tested material (deionized water, 1% starch solution, onion juice, 1% sucrose solution) 3. Fill each test tube with 3ml of the testing solutions, respectively 4. Add five drops of iodine to
Purpose:
An introduction to testing procedures for two large, organic molecules: proteins and starches.
Hypothesis:
In the test for protiens the water, being that it is inorganic will not test positive for protiens; it will serve as the negative control. The milk and 50% egg solution should test positive for protien as they are subsatnce derived from animals which contain protiens in order to carry the functions of life. The sucrose will test negative due to the fact that it is a carbohydrate and not a composition of organic material but rather a single part.
In the test for starches, water again will serve a the negative control for the experiment becasue it is inorganic. it appears obvious the 1% starch solution will test positve for starches becasue it is starch. The onion juice should carry starch due to the fact that starch is stored energy for plants and onions are very bulbous, while the sucrose solution again will not test positive because sucrose is only a part of starch.
Materials:
Test tube rack
4-5 test tubes
Transfer dropper
Deionized water
Evaporated milk
1% sucrose solution
1% starch solution
50% egg white solution
Onion juice
Biuret reagent
Iodine
Methods:
Protien test:
1. Set up four test tubes in the test tube rack.
2. Label each test tube by the tested material (deionized water, evaporated milk, 50% egg white, 1% sucrose)
3. Fill each test tube with 3ml of the testing solutions, respectively
4. Add five drops of biuret reagent to each test tube
5. Swirl each test tube until fully mixed
6. Record the color of each test tube as results Starch test: 1. Set up four test tubes in the test tube rack. 2. Label each test tube by the tested material (deionized water, 1% starch solution, onion juice, 1% sucrose solution) 3. Fill each test tube with 3ml of the testing solutions, respectively 4. Add five drops of iodine to