Biological Molecules Lab Report

Identification Of Biological Molecules

Biology 12 Behrooz Kianian
Period: 4 Partner: Chantelle
Date: Thursday, Nov 7th

Question

1. What happens to protein when they are exposed to very high temperatures?

Proteins exposed to very high temperatures become denatured. Meaning they change shape. If a protein is denatured, it usually can't function the way it is supposed to

2. Contrast carbohydrates and proteins in relation to their chemical structure and their functions in the organism?

Similarities: both contain a carbon backbone, made of smaller structures
called monomers; both are constructed by dehydration synthesis and destroyed by hydrolysis.

Differences: carbohydrates do not contain the amino group, proteins are constructed of amino acids, proteins function in movement, and carbohydrates are a quick energy food made of monosaccharaides.

3. Why are proteins important biological molecules such as antibodies and enzymes composed of protein and no carbohydrate or lipids?

The final product is protein in all the aspects in the cell. Proteins are genetically coded by our body. Carbohydrates are mostly from external source and lipids don’t take any important role, so protein are most require component for our body

4. Name some foodstuffs high in carbohydrate content?

Fructose and Granulated Sugar
Sugary Cereals
Low fat Crackers, Rice Cakes, and Potato Chips
Potatoes (Hash Browns and French Fries)

5. Although carbohydrate are rich source of energy can man survive on diet of consisting only of carbohydrates?

The answer is undoubtedly no because your body is made out of protein and needs small amounts of protein each day growth. Your body must make regulatory substances and needs, not only protein, but also vitamins and minerals.

6. What biological process provides all of the carbohydrates consumed by man?

Photosynthesis, all carbohydrates are either obtained from plants or from animals that ultimately rely upon plants on the food chain.

7. In what form is excess carbohydrate stored in an animal? In a plant?

Fat in animals, Starch in plants.
Plants - starch in storage organs, potato tubers, seeds.
Animals - glycogen in liver and skeletal muscle.

8.
Compare and contrast the chemical nature of fats oils and waxes?

Oils, and waxes are both types of fats except oils are unsaturated fats and waxes are saturated fats.
9. What is the relationship between fats and soaps?

Soaps are made from fats by hydrolysis. Fats are glycerol with three fatty acids, and soaps are the sodium or potassium salts of fatty acids.

10. Explain the result of part four telling how you determined which type of biological molecule your sample contained?

First, we obtained a test tube rack and 9 test tubes.
We had three unknown solutions, A, B, and C.
We filled 3 test tubes with the solution A, the next 3 with solution B, and the last 3 with solution C.
The first set of three test tubes A B C we drops few biuret reagent into it, then we gently shake the test tubes, and observed the test tubes for color change.
In the next set of 3 test tubes A B C we put a few drops of Benedict solution into it and we gently shake the test tubes back and forth and then we put all 3 of the test tubes into the boiling water and after a couple of minutes, we observed the color of the test tubes and then we recorded our observations in the table.
We followed the same procedures for lipids and then we copied down our
observation

11. H

Discussion

Source of error: On each part when we are adding 2 ml of each sample it may not be always 2 ml, it could be more then 2ml or less and this little error could make us to get different observation.

Conclusion

The purpose of this experiment was to perform test to detect the presence of carbohydrates, proteins and lipids, also to explain the importance of a positive and a negative control in biochemical test.
The Benedict’s test is to test for reducing sugars, Iodine test is to test for starch, and Biuret test, is to tests for proteins. We came to a conclusion that biuret solution is a blue liquid that changes to purple when proteins are present and to pink in the presence of short chains of polypeptides. The violet color is a positive reaction in a Biuret test. Proteins give a strong biuret reaction because they contain a large number of peptide bonds for example milk. For part 2 of this lab we are trying to identify carbohydrates and we got to a result that Benedict solution is used to test for simple carbohydrates. Benedict's solution is a blue colored liquid that contains copper ions and when Benedict's solution and simple carbohydrates are heated, the solution changes to orange and red for example Dextrose. As we all know from experience, lipids leave translucent spots on unglazed brown paper bags and the reason lipids make a translucent mark on brown paper is because their small particles fill up the spaces in the paper and based on this observation a translucent spot is visible, then the presence of lipid has been
verified.