Bio Lab Report
Alhia Harris
October 18, 2011
Biology Lab report
Proteins are very important throughout the body. They have a lot of functions in cells. Antibodies are proteins that help cells rebuild the cells when they are destroyed. Transport proteins move substances from one place to another. Regulatory proteins control cellular metabolism in a way that cells throughout the body can have the right amount of glucose in the blood. A common protein is an enzyme; in cells they speed up chemical reactions. For an example, “amylase is an enzyme that speeds up the breakdown of starch in the mouth and small intestine” pg 28. All proteins are made up of amino acids. There about 20 different amino acids that is found in cells. A chain of two of more amino acids is called a peptide and the bond between the different amino acids is called a peptide bond. Very long chains of amino acids are called polypeptide. In addition, a protein can have one or more polypeptide chains. To test for proteins, one must use biuret reagent. “Biuret regent contains solutions of sodium or potassium and a small amount of dilute copper sulfate solution” pg 28. The reagent then changes color to see if there is a sign of proteins. I think that the distilled water will show a negative result, Albumin will show a positive result, Pepsin will show a positive result and starch will show a negative result. For this experiment a person would need biuret reagent, four test tubes, distilled water, Albumin, Pepsin, and starch, a ruler and a wax pencil. First you get each tube and you measure up the 1cm point and then you mark the point with the wax pencil. For each tube you have to add the different contents up to the 1cm mark. Then for each tube you add five drops of biuret reagent. Last, you record the different color changes that you saw.
Biuret Test for Proteins
Tube
Contents
Conclusion
1
Distilled Water
Negative
2
Albumin
Positive
3
Pepsin
Positive
4
Starch
Negative
In order to show that proteins are
October 18, 2011
Biology Lab report
Proteins are very important throughout the body. They have a lot of functions in cells. Antibodies are proteins that help cells rebuild the cells when they are destroyed. Transport proteins move substances from one place to another. Regulatory proteins control cellular metabolism in a way that cells throughout the body can have the right amount of glucose in the blood. A common protein is an enzyme; in cells they speed up chemical reactions. For an example, “amylase is an enzyme that speeds up the breakdown of starch in the mouth and small intestine” pg 28. All proteins are made up of amino acids. There about 20 different amino acids that is found in cells. A chain of two of more amino acids is called a peptide and the bond between the different amino acids is called a peptide bond. Very long chains of amino acids are called polypeptide. In addition, a protein can have one or more polypeptide chains. To test for proteins, one must use biuret reagent. “Biuret regent contains solutions of sodium or potassium and a small amount of dilute copper sulfate solution” pg 28. The reagent then changes color to see if there is a sign of proteins. I think that the distilled water will show a negative result, Albumin will show a positive result, Pepsin will show a positive result and starch will show a negative result. For this experiment a person would need biuret reagent, four test tubes, distilled water, Albumin, Pepsin, and starch, a ruler and a wax pencil. First you get each tube and you measure up the 1cm point and then you mark the point with the wax pencil. For each tube you have to add the different contents up to the 1cm mark. Then for each tube you add five drops of biuret reagent. Last, you record the different color changes that you saw.
Biuret Test for Proteins
Tube
Contents
Conclusion
1
Distilled Water
Negative
2
Albumin
Positive
3
Pepsin
Positive
4
Starch
Negative
In order to show that proteins are